Engineering
THE AMERICAN MACHINIST
SHOP NOTE BOOK
THE
AMERICAN MACHINIST
SHOP NOTE BOOK
A Collection of Articles, Written for the American
Machinist by Practical Men, Covering a Wide
Variety of Machine Shop Activities and
Giving the Solutions qf Problems that
have Arisen in Machine Shops
the World Over
COMPILED BY
E. A. SUVERKROP
Associate Kdnor American Machinist,
Member A. 8. M. E.
FIRST EDITION
PUBLISHED BY
AMERICAN MACHINIST
McGRAW-HILL BOOK COMPANY, INC.
SOLE SELLING AGENTS
239 WEST 39TH STREET, NEW YORK
1919
Library
COPYRIGHT, 1919, BY THE
McGRAW-HILL COMPANY. INC.
PEEFACE
Many of the kinks shown in this book are from your own
pen or from the pens of men you have known and worked with.
They are the solutions of problems similar to those that you and
I and all other mechanical men bump into. Few of us have
access to a file of the American Machinist, but even when such a
file is within reach it is often difficult to find what is wanted.
The object of this kink-book is to preserve in permanent and
accessible form selected articles covering work performed on vari-
ous machine tools.
A book like this is of twofold value :
First It shows exactly how a certain specific job was success-
fully accomplished. Unfortunately it is seldom that the other
man's device or method can be used by others exactly as it was
used by him. Either the work itself is somewhat different or
the shop equipment is not the same. Only where all the condi-
tions are similar can we use the other man's device in its entirety
for our work.
Second To a far greater degree is such a book valuable be-
cause of what it suggests. This function of suggestion is limited
only by the ability and resourcefulness of those who find their
suggestions here. A kink here elaborated in connection with a
milling machine may with slight alterations be applicable to the
lathe, drill press or planer.
The field of machine-shop work is so wide that no book can
cover it, but the experiences gathered in this compilation can be
of great assistance to the ingenious mechanic in suggesting a
way out of his troubles.
THE COMPILER
CONTENTS
Section i
DRAFTING AND DESIGN PAGE
KEEPING DOWN EXPENSES IN THE DRAFTING DEPARTMENT .... 1
THEORETICAL vs. PRACTICAL ACCURACY 3
EFFICIENCY IN SPECIAL-MACHINERY DESIGN 4
MAKING DRAWINGS FOR PATTERNMAKER AND MACHINIST 5
CHANGING PART LISTS 7
DRAFTING-TABLE COVER 7
ALLOWANCE FOR CLEARANCE IN CORED HOLES 7
TABLE OF ANGLES FOR DIVIDING CIRCLES AND LAYING OUT POLYGONS . 9
PROPORTIONING A BORING BAR FOR MAXIMUM STIFFNESS 10
CHART FOR DETERMINING OF PULLEY CROWN DIMENSIONS 12
CAMS FOR SMALL AUTOMATIC MACHINERY 13
ROLLER BEARINGS IN MACHINE-TOOL DESIGN 13
PACKING FOR EXPORT 17
GRAPHICAL GEOMETRICAL PROGRESSION BY MEANS OF THE SLIDE RULE 18
INFLUENCE OF CENTRIFUGAL FORCE ON THE PULLING POWER OF A BELT 19
BLUEPRINTS FROM PENCILED TRACINGS 20
SPEEDING UP THE OLD BLUEPRINT MACHINE 21
GUARD FOR DRAWING TABLE 23
BLOTTING OUT DIMENSIONS ON BLUEPRINTS 24
EXTENSION FOR USE IN DRAWING LARGE RADII 24
SIMPLE ELLIPSOGRAPH 25
Section 2
PATTERNS AND FOUNDRY
FUSIBLE METAL FOR SOLDERING 26
PATTERNS FOR WORK WITH PROJECTING MEMBERS 27
BREAKING UP CAR WHEELS 27
TOOL FOR DRIVING BRADS 28
ADVANTAGES OF PLATE PATTERNS 28
CORE Box DOWEL PINS 30
PATTERNS FOR LARGE BEARING CAPS 31
CASTING A STEEL WORM * . . 32
TURNING SMALL BOSSES FOR USE IN PATTERN WORK 32
RAPPING PLATES FOR PATTERNS 33
A PATTERN PROTECTOR 34
MARKING W T OOD PATTERNS FOR THE PURPOSE OF IDENTIFICATION ... 35
EFFICIENT HERRINGBONE GRATE PATTERNS 36
yii
viii CONTENTS
Section 3
FORGE SHOP, HARDENING AND TEMPERING PAGE
STANDARD MARKING FOR DISTINGUISHING THE VARIOUS STEELS ... 40
FORGED HIGH-SPEED BITS 41
OXYACETYLENE WELDING HlGH-SPEED STEEL TO MACHINE STEEL . .41
ARC-WELDING HIGH-SPEED TOOL TIPS ... .43
ECONOMIZING HIGH-SPEED STEEL WITH THE ELECTRIC BUTT WONDER . 44
COST OF WELDED HIGH-SPEED TOOLS 45
BRAZING STELLITE 46
SOME HARDENING KINKS 47
HARDENING HIGH-SPEED STEEL TOOLS . . 48
HARDENING FORMED HIGH-SPEED CUTTERS 50
REPAIRING A BROKEN CRANKSHAFT ... 52
REPAIR WORK FOR STEAM-HAMMER PISTONS ........ 55
RECORDING CYLINDER AND PISTON REPAIRS 57
BALL-JOINT PISTON ROD FOR STEAM HAMMER 58
A SPRING-HEATING FURNACE 59
FURNACE FOR OIL-TEMPERING BATH 61
FORGING HIGH-SPEED STEEL 61
BENDING HEAVY PIPE IN THE BLACKSMITH SHOP 63
BENDING SHORT RODS HAVING THREADED ENDS 65
RECLAMATION OF MATERIAL IN THE SHOP 67
ANNEALING HARD SPOTS IN OXYACETYLENE REPAIRS 68
PREVENTING CRACKS IN HARDENING 68
TEMPERING THIN SNAP GAGES 69
BRAZING A BROKEN PAIR OF SCISSORS 70
SHRINKING ON A LARGE SLEEVE 71
Section 4
DRILLING MACHINE
POSITIVELY LOCATED DRILL JIG 73
AN ADJUSTABLE ANGLE IRON 74
MAKING ANGLE-FACED WASHERS . 75
AN ADJUSTABLE JIG FOR DRILLING ROUND PIECES 76
CUTTING HOLES IN GLASS . . . ... 77
A JIG FOR DRILLING STEEL DISKS 79
SMALL MOTOR-DRIVEN DRILLING MACHINE USED FOR TAPPING ... 80
INCREASING THE SIZE OF A SHELL REAMER 80
ECONOMICAL HIGH-SPEED STEEL COUNTERBORE 81
A RADIUS-CUTTING BORING BAR 82
FIXTURE FOR DRILLING SMALL HOLES 83
BORING ENGINE GUIDES . . . . . . . . 85
DRILL GIG FOR Y CONNECTIONS 85
REDUCTION HEAD FOR DRILLING MACHINE 86
DRILLING MACHINE MADE INTO A PRESS 87
SPECIAL COUNTERSINKING TOOL . 88
CONTENTS ix
PAGE
RECESSING TOOL 89
DRILL-CENTERING DEVICE FOE V-BLOCKS 90
MACHINING BEVEL PINIONS . . . ... . 93
SIMPLE DRILLING JIG FOB USE ON A YOKE CASTING 94
Section 5
ENGINE LATHE
THBEADING DIAL 96
BREAKAGE OF ROUGHING TOOLS 97
SPHERICAL TURNING WORK 98
A SAFETY LATHE DOG 99
CHUCK WRENCH REPAIRS 99
EMERGENCY FOLLOW REST 100
FACING THE Boss ON A LARGE CASTING 100
ANGLES FOR SQUARE-THREADING TOOLS 101
FINISH-TURNING WITH STELLITE 102
SELF-CENTERING WORK CARRIER FOR USE IN A STEADYREST .... 1.03
QUICK REPAIR FOR TAIL SPINDLE OF LATHE 104
QUICK METHOD OF THREADING SMALL CAST-BRASS RINGS . . . .105
IMPROVED LATHE CENTERS 106
CUTTING COARSE-PITCH SCREWS 107
CUTTING A WORM OF RAPID LEAD 10$
NONSLIP EXPANDING MANDREL 100
SETTING A TAPER ATTACHMENT BY MEANS OF A DIAL INDICATOR . .Ill
ARC-FORMING ATTACHMENT FOR LATHE AND SHAPES Ill
OLD LATHE USED AS A BROACHING MACHINE 113
BROACHING HOLES ON THE LATHE 113
SIMPLE CALCULATION OF CUTTING TIME 115
A FLOATING REAMER HOLDER 115
JIG FOR TURNING ENDS OF SQUARE TOOLS . . . 116
GANG TURNING FIXTURE 117
THREAD-CUTTING TOOL 118
CHUCK FOR NIPPLES AND STUDS . 119
CORRECTING UNTRUE CENTER HOLES . . 119
PISTON-GROOVE SIZING 120
Section 6
THE MILLING MACHINE
TOOL FOR LAYING OUT WORK: IN THE MILLING MACHINE . . . . .122
CROWNING PULLEY FACES ON THE MILLER 122
AN ADJUSTABLE V-BLOCK .. ... * * . . . . 124
DOING A LARGE JOB ON A SMALL MILLING MACHINE . . . . . .124
THE MILLING-MACHINE VISE AS A SPECIAL MILLING FIXTURE . . . 126
SETTING ANGLE FOR FLUTING TAPER REAMERS 128
POINTER TO SUPPLEMENT TABLE-FEED STOP ON MILLING MACHINE . . 129
CHART FOR DETERMINING APPROACH FOR MILLING CUTTERS . .130
x CONTENTS
PAGE
ADJUSTABLE LOCATING BUTTON
BORING A HOLE ABOUND A CORNER .
EFFICIENCY IN MILLING FIXTURES 132
AN ADJUSTABLE SIDE-MILLING CUTTER . . . . ... .133
A LATHE JOB ON A MILLING MACHINE .134
CLAMPING FLAT SQUARED WORK ... .135
ADJUSTABLE BORING-TOOL HOLDER FOR THE MILLING MACHINE . .137
MILLING VISE FOR USE BETWEEN CENTERS 137
SETTING TOOL FOR USE WITH MILLING CUTTERS 138
Section 7
PLANER AND SHAPER
REPAIRING OLD PLANING MACHINES 139
A SHAPING MACHINE REPAIR JOB .141
MACHINING A LONG RECTANGULAR HOLE 141
ADJUSTABLE EXTENSION PLANING TOOL 143
A TOOL FOR INTERNAL PLANING 144
RADIUS PLANING TOOL . . 145
A REPAIR KINK ON A PLANING MACHINE 146
DEVICE FOR HOLDING LARGE JOB ON SHAPING MACHINE 147
CUTTING A NARROW SLOT WITH THE SHAPING MACHINE 148
SQUARING THE ENDS OF SMALL RECTANGULAR PIECES 149
TURNING AND BORING ATTACHMENT 149
DIVIDING ON A LATHE OR SHAPEB 150
Section 8
TOOL MAKING
AUXILIARY BUSHING PLATE IN TOOL WORK 151
AN ECONOMICAL COUNTERBORE 154
BUTTONS FOR MEASURING ANGULAR WORK 155
CARTRIDGE-PUNCH TEMPLET 155
MAKING A CIRCULAR FORMING TOOL 156
CASEHARDENED JIG BUSHINGS . . . '. 158
ADDING LIFE BY TAKING CARE OF A MICROMETER ....... 158
GRINDING PRECISION TOOLS . . .' . . . .159
LOCATING HOLES ON CLOSE CENTERS BY MEANS OF SPECIAL BUTTONS . 160
A THREAD-GRINDING FIXTURE 161
MAKING A HEIGHT GAGE OUT OF A VERNIER CALIPER 163
A RADIUS TRUING FIXTURE FOR USE ON GRINDING WHEELS . . . .165
ACCURATE SETTING DEVICE FOR INTERNAL GRINDING . . . . . .166
TRANSFER GAGE FOR PIERCING DIES 168
USEFUL ANGLE PLATE . . 168
CONTENTS xi
Section g
DIE AND PRESS WORK PAGE
SHEET-METAL, WORK 171
LOCATING SMALL HOLES ACCURATELY IN DIE WORK . . , . . .173
ARRANGEMENT FOR A LARGE COMBINATION DIE 176
A WIRE BENDING DIE 177
PROGRESSIVE DIE FOR RUBBER WASHERS 178
PRODUCING A BULGE IN TUBING . .180
MAKING PIERCING PUNCHES 181
PIERCING OPPOSITE SIDES OF THIN SHELLS 182
PRESS KINK FOR BLANKING CLOTH OR OTHER SOFT MATERIAL, . . . 183
SPRING -FORMING DIE 184
SOME PRESS-TOOL POINTERS 185
PIERCING OBLIQUE HOLES 188
A FREAK SHELL ITS CAUSE AND CURE . . . 189
BENDING DIES FOR TUBING 190
SPRING OPERATED PUNCH PILOT 191
Section 10
GAGES
GAGE GRINDING MACHINE 192
SPECIAL V-BLOCK FOR GRINDING WORK 194
DEVICE FOR MEASURING THREAD GAGES 194
PROBLEM IN GAGE TESTING 190
THE USE OF FEELER GAGES 196
ADJUSTABLE FEMALE THREAD GAGE 197
A GAGE FOR DEPTH OF RECESSES 198
FEELER GAGE FOR RECESSES 198
GRINDING CORRECT RADIUS ON A GAGE 198
BUILT-UP LIMIT SNAP GAGE . . . . . . . ' 200
AN AMPLIFYING GAGE . 201
INSPECTION GAGE 202
ERRORS IN MEASURING THREAD PITCH DIAMETERS WITH WIRES . . . 203
PLASTER OF PARIS FOR SEALING HOLES IN GAGES ....... 205
GRINDING SNAP GAGES 205
Section n
GRINDING
KEEPING NOTES ON GRINDING 207
MOUNTING, BALANCING AND DRESSING GRINDING WHEELS . . . .210
SAVING TIME AND ABRASIVE WHEELS 211
GRINDING THE EDGES OF CIRCULAR PLATES . . ,. .. ^ .;'.'. .211
W T HEELS FOB TOOL AND CUTTER GRINDING 213
xii CONTENTS
PAGE
GRINDING THIN PIECES 215
RADIUS WHEEL-DRESSING FIXTURE 217
GRINDING A COUNTERSINK IN CHILLED CASTINGS 218
A FIXTURE FOR GRINDING 219
DIAMOND HOLDER FOR NORTON GRINDER 220
Section 12
BORING
PORTABLE CYLINDER-BORING MACHINE 221
A BAR FOR BORING A CHAMBER 224
BORING BAR FOR TORPEDO TUBES 225
BORING TAPER HOLES 225
BORING A 4-FT. HOLE IN AN 18-FT. SHIP CASTING 226
PRODUCTION CHUCK FOR A BORING MILL 229
DRIVING-BOX CHUCK 229
CENTERING WORK WITH GRADUATED WEDGES 233
Section 13
GEARING
DECIMAL-EQUIVALENT TABLE USEFUL IN GEAR WORK 235
INTERMITTENT WORM GEAR . 237
FORMULA FOR OBTAINING CUTTING ANGLE OF HELICAL GEABS . . . 238
Section 14
SCREW MACHINE
MACHINING A 5%-iN. PISTON ON A 3V4-IN. GRIDLEY AUTOMATIC . . . 239
TIME STUDIES IN SCREW-MACHINE PRACTICE 242
SLOTTING AND SHAPING IN THE AUTOMATIC SCREW MACHINE . . . 242
GUARD FOR DEFLECTING COMPOUND . 245
TOOL FOR REMOVING BURRS FROM JAM NUTS 245
SENSITIVE TAP AND DIE HOLDER 246
THREAD ROLLING IN THE AUTOMATIC SCREW MACHINE . . . . . 247
HOLLOW SETSCREW AS AN "ADAPTER" 251
Section 15
SHOP TOOLS, APPLIANCES AND EXPEDIENTS
CONSERVATION vs. EFFICIENCY 253
IMPROVED DRIP CAN FOR HANGERS . . . 254
METHOD OF RECLAIMING WASTE 254
INSTALLING OVERHEAD APPARATUS REDUCES OVERHEAD EXPENSE . . 25f>
ECONOMY IN HACKSAW BLADES 256
REPAIRING BELT SHIFTER . .257
CONTENTS xiii
PAGE
AIR-HOIST PISTON PACKING 257
SECURING CRANE HOOKS 258
POWER DEVICE FOR " SPOTTING-!N " PARTS 259
IMPROVED HALF-ROUND TAPER REAMER 261
HOLDER FOR COUNTERSUNK HEAD BOLTS . . 261
TAPPING BRONZE FEED NUTS 262
PORTABLE PRONY BRAKE 263
BUSHING A LOOSE PULLEY 264
SURFACE-GAGE KINK 264
OPERATING VALVE FOR PNEUMATIC CHUCKS 264
HANDY TOTE Box 266
DRILLING THIN STOCK 266
TEMPLET FOR MARKING OFF FLANGES 268
IMPROVED HERMAPHRODITE CALIPER 270
WHITE SURFACE FOR LAYOUT 270
IMPROVED GEAR PULLER 270
BOLTS STUCK IN SOCKET WRENCH IN BOLT-CUTTER 272
DEMAGNETIZING HIGH-SPEED STEEL 272
RAISING THE "VISIBILITY" OF THE OIL HOLES IN SHADOWED POSITIONS 272
A BRAKE FOR HIGH-SPEED MACHINES 273
LENGTH OF BELTING IN COILS 273
EXPANDING AIR CHUCK 274
TUBE-BENDING DEVICE 276
CONCEALED SPRING FOR USE ON A RATCHET PAWL 276
AN EMERGENCY REPAIR JOB 277
OVERCOMING LOOSE-PULLEY TROUBLE ON A SPECIAL DRIVE .... 279
COOLING A SMALL AIR COMPRESSOR 280
SMALL STUD GEAR FOR ENGINE LATHE 281
OPERATING SIGNAL BELLS FROM A GENERATOR 282
SPEED-REDUCTION DEVICE WITH NOVEL AND VALUABLE FEATURES . . 283
AN ADJUSTABLE GEAR FOR ELIMINATING BACKLASH 284
ELIMINATING BREAKAGE OF BOLTS ON HIGH-SPEED MACHINERY . . . 285
A PNEUMATIC RAM 285
CUTTING A KEYWAY ON A LARGE PULLEY 287
AN EMERGENCY REAMER 288
CROWNING A LARGE PULLEY 288
WHY BELTS JUMP 289
FASTENING LOCKNUTS 289
KEEPING BELT GLUE IN A BOTTLE 289
PREVENTING GREASE-CUP TROUBLE 290
A MOLD FOR BABBITT HAMMERS 290
FIBER HAMMER 291
COMBINED HARD AND SOFT HAMMER 292
How TO KEEP A HAMMER ON THE HANDLE 293
INDEX . . . 295
THE AMERICAN MACHINIST
SHOP NOTE BOOK
SECTION I
DRAFTING AND DESIGN
KEEPING DOWN EXPENSES IN THE DRAFTING
DEPARTMENT
THE ultimate object of the drafting department is to supply
the factory and production departments with drawings or prints,
and this should be done accurately and uniformly.
To begin with all drawings should be made in fixed sizes, and
if the quantity is large these sizes are generally bought already
cut; if not, then drawing paper may be bought in sizes 36 x 48
in. This size of sheet may be used for the layout of the machine
or apparatus, but for detailing, smaller sheets are better; the
36 x 48-in. sheet may be divided into two sheets 24 x 36 in., or
into four sheets 18 x 24 in. If these sizes are still too big they
may be divided again into eight sheets 12 x 18 in. or 16 sheets
each 9 x 12 in.
It will be seen that in all these divisions there is no waste
paper ; therefore, to sum up, one sheet of paper 36 x 48 in. will
give two sheets 24 x 36 in., four sheets 18 x 24 in., eight sheets
12 x 18 in. or 16 sheets 9 x 12 in.
The same method applies to tracing cloth, which may be
bought in sheets 36 x 48 in. or in rolls 48 in. wide.
Having been asked to cooperate with the supervisor in cutting
down the expenses of the drafting department, which had been
continually climbing, we found a large amount of layouts and
old designs that were made on tan Saxon drawing paper in sizes
36 x 48 in. The other side of the paper was not used and was
clean, so We cut up the sheets and used them for detailing, with
1
EAJtf/ItACHINIST SHOP NOTE BOOK
the result that we saved six months' supply of paper, and draw-
ing paper at the present time comes high. If a good grade of
drawing paper is being used (sized on both sides) save the
drawings and use the other side later on.
We also incorporated the charge-up plan for stationery; that
is, when a draftsman needs pencils, etc., they are charged against
him as a matter of record, which tends to keep the men's wants
uniform; also each tries to do with less than his neighbor. At
the end of the month the lists are gone over, and it is gratifying
to see how evenly the accounts balance pencils, paper and
erasers on the designers' account, and tracing cloth, ink and
pens on the tracers' account.
One of the best time savers in the drafting department is a
good system of filing prints. Much time is wasted in the draft-
ing department looking for a print that should be on file. Some
companies think that installing a filing system for prints is a
needless expense. However the first cost is the only expense in-
volved, as after that it only means paying a bright boy or girl
to keep the system running right.
Compass lead, while not expensive, is worth saving. In our
department we have dispensed with this article and our compass
lead is obtained in the following manner : When a draftsman
gets a drawing pencil from stock he turns in the stub of the old
one, the lead in the stub being about 1 in. long. This stub is
cut away and the lead saved, so this is given out for use in the
drawing instruments. Lead in most every degree of hardness
is collected in this way.
Another item of expense is tracing layouts and detail drawings
for experimental work. Most designs undergo extensive changes
before they finally go into production, and it is not necessary to
have these traced on tracing cloth with ink. Drawings may be
sent to the model room, and in order to keep them clean the
machinist or model maker may put a piece of glass over the
drawing while he is using it. If the model proves satisfactory
the pencil drawings may then be traced for manufacturing pur-
poses.
Shading and Cross-Sectioning. In sending out drawings
from the drafting department there is a tendency on the part of
the draftsman to do a maximum amount of shading and cross-
sectioning. This looks very well, but if it detracts from the
DRAFTING AND DESIGN 3
accuracy of the drawing it should not be done. I have seen
drawings that were perfection as far as display was concerned,
but, when assembled, the parts made from these drawings repre-
sented a lot of junk.
Leave all fancy work for the display draftsman or the Patent
Office draftsman, and send to the factory the correct dimensions
rather than beautiful shading.
Mkny manufacturing plants will not allow cross-sectioning to
be done with ink. The tracing is turned over, and all sectioned
parts are filled in with black-carbon pencil, which is a faster
method. At present, when raw material is so hard to get, the
designer should use standard material wherever possible. The
difference of a few thousandths of an inch in thickness may
mean a month's delay in receiving the raw material at the fac-
tory. All manufacturing firms generally send out catalogs of
their wares, which should be kept handy for the draftsman's
reference.
This rule applies to screws, rivets, bolts, etc. The designer
should remember that these are made in standard lengths, and
will in all probability work into his design just as well as a spe-
cial length.
THEORETICAL VS. PRACTICAL ACCURACY
I concede the facility with which theoretical dimensions may
be laid down even to the nth decimal degree, but the physical
limitations and restrictions in the way of applying these meas-
urements are such as to lead me to doubt their practicability.
Prof. Perry in a course of lectures to London workingmen
pointed this out when he said: "What is the use of expressing
the results of our calculations to the sixth or seventh decimal
place, when for all practical purposes the last three or four are
useless!" In an article on page 749, Vol. 47, American Machin-
ist, on "Uses of the Sine Bar," the author says: "so we set the
stud B, Fig. 1, 0.20795 higher than the stud A." Referring to
the illustration we observe that the tool used for determining this
measurement is a gage.
Now, is there a vernier upon which it is possible to measure
not estimate accurately, to less than 0.001 in.?
I do not believe there are many toolmakers who would agree
4 AMERICAN MACHINIST SHOP NOTE BOOK
to set a vernier even to 0.0005 in. and gamble next week's pay
envelope on the accuracy of the result.
Assuming that we have a gage capable of being set, and a man
capable of reading it to 0.00001 in., there are many other things
that must be taken into consideration. In the measurement of
angles by the use of the sine bar and plate we must be sure of
the accuracy of the sine-bar studs, their relative positions on
the bar, the absolute truth of the plates, etc., and must take
into account the constant minute changes due to local tempera-
ture changes in handling, all of which tend to remove such a job
from the scope of a toolroom and place it within that of a
laboratory if we are to depend upon the accuracy of the results.
It was stated in a recent issue of the American Machinist that
an American firm of some size refused an order for gages on the
ground that they could not guarantee them to be correct to the
fourth place of decimals. This is apt to cause one to wonder if
a good deal of the so-called accuracy is not of a doubtful qual-
ity; at the same time, in the writer's opinion it points to a high
degree of moral courage on the part of that firm, that might be
followed by others to their advantage.
EFFICIENCY IN SPECIAL-MACHINERY DESIGN
Where the quantity of parts manufactured will warrant the
expense, the special, single-purpose machine is a most important
factor in the reduction of manufacturing costs.
Much of the trouble and difference of opinion regarding the
correctness of design of machines of this class will be entirely
eliminated if suggestions and ideas are solicited from those who
are interested in the building of the machines. In this way, an
understanding as to what will constitute the best machine for a
certain purpose is arrived at before any work is started in the
drawing room.
This cooperation will prove of undoubted advantage if the
contemplated machine is new in type and there is no previous
experience to serve as a guide. Quite often such a machine is
started with a full-size or half -size layout that is a puzzle to the
shop man who, because of his knowledge of the work that the
machine is intended to do, is asked to give an opinion as to its
practicality.
DRAFTING AND DESIGN 5
The maze of lines on a drawing for a machine of this kind
may be clear enough to the designer and to those who have been
in touch with it continually, but it will prove perplexing to the
average man who is called on to give his opinion in the com-
paratively short space of time usually allowed for this purpose.
A better way is to start with a preliminary design, either one-
eighth or one-quarter size, whichever is considered necessary,
this drawing to show only enough lines to convey the general
idea of the machine. This design may be submitted for criti-
cism to those directly interested.
A discussion of the matter may change the entire scheme.
This preliminary drawing is cheap to begin with and, being
stripped of much detail, is readily understood.
MAKING DRAWINGS FOR PATTERNMAKER AND
MACHINIST
The following method has been successfully used to provide
permanent and complete drawings for both pattern and machine
shops at practically no increased cost over the usual method.
The drawing is made in ink on tracing cloth in the regular
way, but only such dimensions and notes as are required by the
machine shop are filled in.
A vandyke or brown negative print is then made from the
tracing. This print is filed as the regular machine-shop trac-
ing, and from it prints are made for the machine shop, as re-
quired.
All patternmakers' dimensions and notes are added to the
original tracing, from which pattern-shop prints are made when
needed.
With this method the machine shop is supplied with positive
prints instead of the usual negatives. If, for any reason, this
is objectionable, and it is desired to furnish the usual negative
print to the machine shop, a positive vandyke may be made from
the original negative vandyke and the negative blueprints for
the machine shop made from that.
If castings from the same pattern are to be machined to dif-
ferent dimensions, a positive vandyke is made from the original
negative, blanking off in the printing all dimensions which are
to be changed, as well as drawing numbers, notes, etc., not
6 AMERICAN MACHINIST SHOP NOTE BOOK
needed, even including drawing lines if any are to be changed.
The omitted numbers, dimensions, etc., are filled in, and a com-
plete new tracing results at very small expense.
If a comparatively small number of blueprints are required,
the vandyke may be made on paper; but if they are to be sub-
jected to considerable handling, they should be made on cloth.
Another way that proves very satisfactory is to make the
drawings for the machine shop in ink on tracing cloth, and the
sketches for the patternmaker on pencil tracing cloth. The ink
tracing has only the dimensions for the machinist, while the
pencil tracing contains those for the patternmaker alone.
The pattern sketches are made full size whenever practicable,
so that the patternmaker can if necessary scale the blueprints
made from the pencil tracings. The drawings for the shop can
be reduced to scale, all the machinist's dimensions being put on
so that no scaling will be necessary. By this method each work-
man has the dimensions and notes he needs, and no others to
confuse him. The pattern sketches are made directly on the
pencil tracing cloth, thereby saving the time for tracing, while
for the ink tracings a pencil drawing is first made and then
traced on the cloth, unless the piece is simple ; in that case it is
drawn directly on the cloth in pencil and then inked. Some-
times it is not necessary to make a pattern sketch, because the
patternmaker can work from the machinist's blueprint.
Drawings for gages, jigs and fixtures can be made on pencil
tracing cloth and the blueprints sent to the shop. This is an
easy and rapid way. A pencil tracing is sufficient, because only
a few prints will be made. It may, in fact, be used but once,
and it is therefore not wise to spend time to make an ink trac-
ing.
Another method is to make the drawings on drawing paper,
the drawing then being tacked on a light board and shellacked.
When dry, it is ready to be sent to the shop. When returned
to the drawing room, the surface is scrubbed with soap and
water, the drawing removed from the board and filed away.
The pencil tracing method is by far the better of the two for
gages, jigs and fixtures. Small drawings can be protected in the
shop by slipping them into holders made by bending over three
edges of a sheet of tin. The face is covered by thin celluloid.
DRAFTING AND DESIGN 7
CHANGING PART LISTS
A scheme that eliminates re-inking the box lines on a tracing
of a part list or a bill of material is to have the lettering on the
opposite side of the tracing from the box lines. Thus when there
is a change, the lettering will be the only inking erased, as the
box lines, being on the opposite side of the tracing, are not
touched by the eraser.
Care should be taken when the original is traced to see that,
when the side with the lines is reversed, the guiding inclosure
or box lines of the bill of material or part list will be in the
correct positions.
DRAFTING-TABLE COVER
I know of no more convenient cover for the drafting table
than a roller shade. It has the great drawback, however, that
loose tracings are drawn into the roller occasionally and thus
mysteriously disappear. In order to avoid this, I mount the
FIG. 1 DRAFTING TABLE COVER
roller shade on a strip of wood about the same length as the
table; and this strip of wood I screw on the rear edge of the
table. The upper edge of the strip should be from 2 to 3 in.
above the- top of the table.
ALLOWANCE FOR CLEARANCE IN CORED HOLES
The clearance necessary between certain parts of castings, the
conditions that determine the differences in the amount of
clearance allowed, can be learned only by blunders in the shops.
Very seldom a hard and fast rule can be formulated ; experience
is the only sure guide.
s
AMERICAN MACHINIST SHOP NOTE BOOK
One of the commonest cases is that of " black" bolts and the
holes. It is more costly to drill holes through a considerable
depth of solid metal than to core them ; hence, the reason of
using more often cored holes in preference to black, or turned,
bolts in drilled holes. There are sometimes exceptional cases
noted of special machines and special work. The general ob-
FIG. 2 CHAMBERED COBED HOLE
jection to cored holes is that the inaccuracy makes it impossible
to fit the bolts closely in the holes and therefore the holes must
be made larger in diameter than the bolts, figuring by the
amount of expected inaccuracy. The clearance will vary be-
tween %2 and % in. or even more, depending entirely on the
circumstances.
Length of Cores Important in Castings. The length of the
core and the direction of it always have to be considered in de-
ciding the amount of clearance to be given in cored holes ; these
are the most essential two points. It is easier to core a short
hole true than a long one, and to insure exactness of a core set
vertically in a mold than that of one laid horizontally and ob-
liquely. For a short core set vertically and stayed with a top
print, a slight allowance for clearance will suffice. But even
then, with the core box made correctly to size and shape and the
prints carefully fixed, the molder must insert the cores very
accurately. For these conditions the clearance allowance will be
from %2 to He in.
For cores of 3 or 4 in. in length, the increase of the allowance
must be from %2 to % in. ; from 4 to 5 in. long would need % in.
to compensate for inaccuracy of fixing ; and when 5 or 6 in. are
DRAFTING AND DESIGN 9
exceeded, cores of small diameter cannot be depended on with
even Vs in. of clearance, on account of inaccurate setting and the
liability of the core to be bent by the flow or pressure of the
liquid metal. In cases of long, slender cores the holes should be
given a large amount of clearance, or they should be preferably
chambered as shown. The diameter of the chamber need not be
much greater than that of the clearance hole. If the core be-
comes bent by the liquid pressure, it will cause no trouble, be-
cause it will not affect the short length of the clearance holes at
the end. It also lessens the cost of drilling deep holes, as only
the end portions need be reamed out.
Horizontal Cores. When holes are cored in horizontal posi-
tions, there is a general probability of greater inaccuracy, due to
both the setting of the core and its bending, than when they are
placed vertically. A horizontal core is almost always placed in
pocket prints ; and if the diameter does not correspond with the
semi-diameter of the lower portion of the print, then the amount
of the difference is always on the top side, and the core is set out
of truth by that amount. The core will often become moved
slightly in the print by reason of the sand having been broken
and mended, or pressed and pushed out of place. To insure
accuracy in cores set in drop prints, it is well to make a special
core box, which will fill up the print impressions over the core,
as well as core the actual hole, and to see that the dimensions
of print and core coincide exactly, thus leaving to the molder
nothing but to insert the core. Horizontal cores of considerable
length are more liable than vertical cores to be curved length-
wise by the liquid pressure, as the curving is upward. There-
fore, there is more reason why such cores should be chambered.
TABLE OF ANGLES FOR DIVIDING CIRCLES
AND LAYING OUT POLYGONS
The following table will be found convenient for the drafts-
man or toolmaker. It is not included in the most commonly
used reference handbooks :
Number of Sides Angle Number of Sides Angle
or Segments Deg. Min. or Segments Deg. Min.
3 120 27 13 20
4 90 28 12 51
5 72 29 12 24
Number of Sides Angle
Min.
or Segments
Deg.
Min.
30
12
25
31
11
37
32
11
15
33
10
54
34
10
35
43
35
10
17
36
10
41
37
9
44
43
38
9
28
39
9
14
30
40
9
10
41
8
47
42
8
34
57
43
8
22
44
8
11
8
45
8
22
46
7
50
39
47
7
40
48
7
30
24
49
7
21
51
50
7
12
10 AMERICAN MACHINIST SHOP NOTE BOOK
Nnmber of Sides Angle
or Segments Deg.
6 60
7 51
8 45
9 40
10 36
11 32
12 30
13 27
14 25
15 24
16 22
17 21
18 20
19 18
20 18
21 17
22 16
23 15
24 15
25 14
26 13
PROPORTIONING A BORING BAR FOR MAXIMUM
STIFFNESS
In the boring of 8-in. British shells under the severe condi-
tions imposed by forced production, it was necessary to provide
the stiffest possible boring bar. No computations for strength
were made, as the bar was laid out as large as the space allowed.
The first bars were made of steel castings, but it was found that
to give the best service they would have to be made of ham-
mered steel.
The difficulty was to get a bar that would bore clear to the
end of the nose and yet be rigid enough without obstructing the
washing out of the chips.
Fig. 3 shows the bar in three positions in the shell and indi-
cates the points to be observed in the solution of the problem.
In the upper figure the bar is seen in place for turning the
cylindrical portion; in the second the nose is partly machined.
It will be observed that as the tool approaches the center line of
the shell the cross-section of the bar at the end of the shell in-
creases and that the outline of the forward side has the same
radius as the inside of the nose of the shell. The first bar was
laid out with this part of the bar a straight line, but it was evi-
DRAFTING AND DESIGN
11
dent that this meant either excessive clearance at some points
or interference at others. The best conditions were obtained
by curving it as here shown.
FIG. 3 VABIOUS POSITIONS OF BAR IN SHELL
FIG. 4 SHOWING How THE BAR WAS MACHINED
In the making of the bar time was saved by first milling away
the larger portion of the stock. Next it was suspended on the
centers AA, Fig. 4, and the forward side turned, after which it
12 AMERICAN MACHINIST SHOP NOTE BOOK
was transferred to the centers BB. To bring the part C down
to a 2%-in. radius required handwork to a templet.
The angles of the tool slot are those found best after a lot of
experimenting. The cooling compound was carried in a copper
tube laid in the milled groove at the rear. This delivered it
through the }4-in. hole to the very tip of the tool.
CHART FOR DETERMINING OF PULLEY CROWN
DIMENSIONS
The subject of pulley crowns has been given a great deal of
consideration by various authorities, but in every instance it is
found impracticable to develop for height of crown a mathe-
matical rule that will give uniform results.
It is noticeable that all rules for determining pulley crowns
are given in terms of width of face of pulley and do not con-
sider what is probably an equally important factor, the diameter
of the pulley.
A given point on the crown of a pulley will travel farther in
making a revolution than a given point at the edge of the rim;
and a belt in passing over the pulley either stretches or slips at
the edge or at its center line, in conforming to the pulley crown,
an amount equal to half the difference of lengths of arc of con-
tact at the crown and at the edge. This amount is proportion-
Diameters, Inches
Widths of Face, Inches
. 5 CHART FOR DETERMINING PROPER CROWN FOR PULLEYS OF VARIOUS
DIAMETERS AND WIDTHS
DRAFTING AND DESIGN 13
ately greater as the diameter of the pulley becomes smaller and
is less as the diameter is increased.
The accompanying diagram Fig. 5 was developed with the
diameter as a factor in determining the pulley crown. Refer-
ring to the diagram for ' l Widths of Face, ' ' the values given are
determined by the relative heights of the ordinates and read
direct. The diagram for "Diameter" is the same as that for
" Widths of Face'' inverted, the values of which are likewise
determined by the heights of the ordinates and also read direct.
The sum of the values shown for a pulley of a given face and
diameter is the height of the crown for the pulley. For ex-
ample, required the height of crown a pulley of 48-in. diameter
and 5-in. face. Reference to the diagram for 48-in. diameter
shows the value 0.044 in., and for 5-in. face a value of 0.081 in.
Then 0.044 + 0.081 = 0.125 in., the height of crown required.
It will be observed that the table eliminates the width of face
as a factor at 16-in. width and that diameters are given up to
8 ft. only. Pulleys of greater diameter are usually made for a
specific drive, where other factors, such as speed, length of belt,
are of contact, etc., can be given their proper consideration in
establishing the crown.
CAMS FOR SMALL AUTOMATIC MACHINERY
The proportions Fig. 6 have been used by the writer in
designing wall-paper printing machinery and cigar machinery.
The proportions work out nicely for any sort of small automatic
machinery where weight as well as strength is to be considered.
ROLLER BEARINGS IN MACHINE-TOOL DESIGN
Let us consider first the application of roller bearings to the
countershaft. In many cases, the user has insured against trou-
ble by equipping the boxes, clutches and loose pulleys of his
countershafts with roller bearings.
Many advantages have been found in the use of this type of
bearing, particularly in the use of the hollow helical roller.
Rolling action is substituted for sliding friction, a saving in fric-
tional load from 50 to 75 per cent. This results in a power sav-
ing which makes possible the use of the increased available
14 AMERICAN MACHINIST SHOP NOTE BOOK
power at the spindle of the machine tool, itself. In other words,
increased production may be realized.
While power saving is an economical factor, it is not as im-
portant a one as the advantages in lubrication. With the hol-
low, helical roller there, is lubricant capacity within the rollers
themselves. Then the rollers distribute the oil back and forth
across the bearing surfaces, maintaining an oil film. The oil
used for lubrication is conserved, it does not leak from the hous-
FIG. 6 DIMENSIONS OF CAMS
ing when the housing is properly designed, and yet the bearing is
thoroughly lubricated at all times. It has been found that re-
plenishment of lubrication is not required oftener than three or
four times a year.
Where this type of roller bearing has been adopted, the
periods for inspection of the countershafts have been cut down
from once or twice a week for plain bearings designs, to once in
three or four months. The resultant saving in time, labor and
lubricant is at once apparent.
These advantages cannot be realized however, without an addi-
DRAFTING AND DESIGN 15
tional first cost for the countershaft equipped with the hollow
helical roller. But this first cost may be regarded from two
angles: If it were not justified by the advantages already dis-
cussed, it would be by the additional advantage of insurance.
Inefficient lubrication has been the cause of many failures of
the plain bearing countershaft. By making possible a more
efficient and more reliable system of lubrication, certainty of
operation is insured.
With bearings in the countershafts which eliminate the possi-
bility of a sticking clutch or loose pulley, and which give posi-
tive lubrication to all bearing surfaces, let us consider the added
advantage of insurance. The reports of those who are using the
hollow, helical type of roller bearing concur in this : The added
cost of using this style of bearing is an investment on insurance
which is worth while.
While a countershaft may be the most obvious point for using
this type of roller bearing, the machine tool itself as we shall see,
offers some interesting applications.
Let us stop for a moment and review briefly the essentials of
machine design; namely: (1) Rigid construction in reference
to particular function of machine. (2) Use of metals based on
the granular structure of the metal in hard and soft state. (3)
Lubrication. (4) Symmetry and simplicity of design. (5) Per-
manency of alignment. (6) Accessibility with regard to clean-
ing, lubrication and renewal of parts subject to wear.
Bearing friction in some classes of machines, is an important
factor in determining the power cost of operation. The use of
plain bearings necessitates provision for taking care of wear,
either by providing for adjustment or by bushing, always with
the idea of maintaining alignment.
It is a fact that the factors which determine the life of a
machine tool are the bearings. The roller bearing of the hollow
helical type will increase the first life of a machine tool. By first
life we mean the period of useful life before the machine must be
torn down for repairs or renewals. The reasons for this will be
discussed further on.
It has been found in many cases that the manufacturing cost
of a machine may be materially decreased by simplifying the
design. In many cases the helical roller bearing has replaced
the plain bearing, and a simpler design resulted. Fewer ma-
16 AMERICAN MACHINIST SHOP NOTE BOOK
chining operations are necessary to accommodate the roller
bearing. One of the reasons for this is the fact that no means
need be provided for taking up wear.
When renewals must be made they can be taken care of
quickly and simply. In most types of machine tools the de-
signer faces the problem of vibration. So far as the writer is
aware, the only satisfactory method of absorbing the vibration
on machine tool spindles is by a large mass of metal surrounding
the spindle. However, certain vibrations applicable to gear
shafts, driving shafts, etc., are absorbed by the hollow helical
roller, which possesses the quality of resiliency and absorbs
shocks and vibrations without transmitting them to other por-
tions of the machine tool.
On gear shafts the helical roller bearing has been found highly
satisfactory. Permanency of alignment, a most desirable fea-
ture of gear shafts, is assured. This results in quiet running
gears. Let us now review the points which the writer has en-
deavored to bring out briefly : From the foregoing, we see that
the hollow helical roller bearings are commanding attention
from the designer and manufacturer, as well as from the user,
for several important reasons. (1) They make available addi-
tional power for use in production. (2) They assure absolute
lubrication and require little attention. (3) They insure
against shutdown. (4) They make possible a simpler, more
symmetrical and often a less expensive design. (5) They assure
permanency of alignment. (6) They absorb vibration and are
quiet in operation. (7) They eliminate rubbing friction.
They command attention from superintendent and production
engineer for the following additional reasons: They eliminate
the problem of securing experienced help to scrape in and fit
close-fitting babbitt or bronze bushings; they also make possible
a greater production without additional investment.
MOVING MACHINERY
This applies to the moving of machinery or to the layout of a
new shop or extensions to the old one, first, lay out to convenient
scale on the drawing board a diagram of the floor space to be
occupied, together with all permanent obstructions, as pillars,
piping, etc. On a separate drawing lay out to the same scale
DRAFTING AND DESIGN 17
and in any convenient position, all tools, machines and work to
be placed on the floor, marking each outline plainly for identifi-
cation. With a pair of scissors cut out the pieces outlined on
this second drawing and place them upon the first drawing, ac-
cording to the previously determined arrangement; any inter-
ference will be promptly checked and the pieces may be moved
about until a satisfactory arrangement is found; indeed, it
would be an unusual case where such movement would not sug-
gest a more advantageous arrangement than the one first
planned.
We have located all machines for a new plant and have made
several changes due to expansion, using this method with uni-
formly satisfactory results.
PACKING FOR EXPORT
Satisfactory packing cases or crates call for considerable skill
in their design. This important work is usually relegated to
the shipping clerk instead of the drafting room where it belongs.
During the last three years, because of the enormous volume
of export tonnage moving through our ports, the handling of
freight from cars to lighters and to steamers has been a severe
tax on the packing which is employed by American manufactur-
ers. The writer has always advocated the use of the best mate-
rials and methods in constructing of export packages, and has
never believed that the additional cost was an item to merit
serious consideration.
The foreign competition which all American manufacturers
and exporters have had to meet, heretofore, will be more keen
after the war, and packing will be as much an item of competi-
tion as price; for packing represents a condition of delivery,
and its insufficiency and quality in use prior to the war, is still
a hindrance to the American exporter's foreign trade. The
object of manufacturers of export goods, should be to fortify
themselves in the markets they are now serving, and which will
be sought again by the countries at present out of the competi-
tion.
The company with which the writer is connected has always
been willing to pay for packing that would deliver its manufac-
tures and purchases at their destinations in first-class condition ;
18 AMERICAN MACHINIST SHOP NOTE BOOK
and it still adheres to that policy. This subject is a vital one
for all exporters.
10 > view v
vim cover Kemovea
j E~
::..::^i : t
i- 1
J
?;fcv_-
::^rr::*:^
Section A -A
' 'Comer Straps every
Second Plank Top
and Bottom
FIG. 7
Top View with Cover Removed
; ^-Corner Straps
Top and Bottom
-Straps around Box
FIG. 8
Bottom with Skids-
FIG. 9
FIG. 7 PACKAGE FOB LIGHT MACHINERY
FIG. 8 PACKAGE FOR MEDIUM MACHINERY
FIG. 9 PACKAGE FOR HEAVY MACHINERY
GRAPHICAL GEOMETRICAL PROGRESSION BY
MEANS OF THE SLIDE RULE
The writer has never seen published this method of finding
the successive steps of a geometrical progression by means of the
slide rule and from those with whom he has talked it does not
appear to be of common knowledge. The method can best be
explained by a definite example.
It is required to find six successive geometrical speeds between
25 r.p.m. and 360 r.p.m. (first and last speeds inclusive) :
DRAFTING AND DESIGN 19
First, draw a straight, horizontal line and establish a point at
the left end; remove the slide from the slide rule and lay it
along the line with the 25 reading coinciding with the estab-
lished point. Lay off on the line a length equal to the distance
between the 25 and 360 readings upon the slide ; now divide the
length of line into five equal parts, giving six equidistant points
along the line ; replace the slide along the line, with 25 again at
the established point, and it will be found that 25, 42.5, 73, 124,
212 and 360, the six successive geometrical steps, coincide with
each point in the order of this rotation.
INFLUENCE OF CENTRIFUGAL FORCE ON THE
PULLING POWER OF A BELT
Increasing the pulling power of a belt by an increased arc con-
tact may not always give the desired results. The question came
up, Will a changing of pulleys from 30-in. diameter to 36-in.
diameter, with 500 r.p.m., give an increase in the horsepower
transmitted by the belt?
The following calculations made by using the formulas given
in one of the standard works on belting show the results that
would be obtained. The factors to be considered are the cross-
section of the belt, which for convenience is taken as 14 x 4 in.,
or 1 sq. in. ; the arc contact, which for equal driven and driving
pulley is 180 deg. ; and the coefficient of friction, as found by
the formula
140
500 + v
The actual pulling power of the belt, which is the resultant of
the different forces acting on the belt, may be found by the fol-
lowing formula :
(100.00758/0 _ i) (2A 0.00061036v 2 )
P =
2 >< 1Q0.00758/0
For a 30-in. pulley at 500 r.p.m., v equals 3927 ft. ; and for a
36-in. pulley, 4712 ft. Then 2
140
/ = 0.54 0.51;
500 X 3927
6 = Arc contact in degrees ;
20 AMERICAN MACHINIST SHOP NOTE BOOK
A = 240, a value depending on the tension of the belt under
working conditions.
1Q0.00758/0 - JO - 00758 X - 51 X 18 = 10- 6995
or
0.6995 log 10 = log 0.6995
The corresponding number is 5.007, or 5. Substituting the
above values, we have:
4(2 X 240 159.76)
p = - - -=116.5
and the horsepower transmitted equals
pv 116.8 X 3927
H = - - = - =13.8
33,000 33,000
Calculating in the same way for a 36-in. diameter pulley, we
find p = 94.4, and H = 13.4, showing that the belt would trans-
mit less power than in the first place. Under 2000 ft. per min..
this centrifugal force need not be considered, but at speeds
higher than 4000 ft. a steady decrease in the pulling power of
the belt, under equal conditions, will be found.
BLUEPRINTS FROM PENCILED TRACINGS
If drawings made with pencil on tracing paper are not after-
ward traced with india ink on tracing cloth, the blueprints made
from the paper tracings are sometimes indistinct. In the draft-
ing room of one manufacturing company considerable annoy-
ance was experienced in this respect after the company had
adopted the system of making blueprints from tracing paper, on
account of being rushed for time. There was more trouble
after the drawings became old and less transparent. It was
considered necessary to go over the drawings with pencil and
make the lines heavier, but a better method was discovered.
The back of the tracing paper was painted with cocoanut oil
with an ordinary paint brush, and then wiped clean. After
this the drawings were hung up to dry. No oil was put on the
side of the paper which contained the pencil marks, as it was
desired to leave this side so that erasures and alterations could
be made, When treated in this manner the tracing paper was,
DRAFTING AND DESIGN 21
much more transparent and very good blueprints were pro-
duced.
The effect of the oil treatment is to not only make the paper
more transparent but to make the pencil lines darker. This
latter effect may be more imaginary than real, however.
SPEEDING UP THE OLD BLUEPRINT MACHINE
In a shop where the writer was employed some time ago we
had an electric blueprinting machine of the vertical glass-cylin-
der type with a contact cloth that had to be rolled back and forth
for inserting the tracings. We had trouble with our blueprint
boys, who left us at the rate of about seven a year, and a maxi-
mum day's work was about 275 prints. We needed nearly
double this number at times, and when we appealed to the
manager for another machine he wanted to know if we wanted
another one of the same kind.
He observed the cutting of the paper, the rolling back and
forth of the contact cloth, winding up the escapement mechan-
ism, getting tue prints into the water, slushing them with a brush
and then putting them on a rack to dry. Then he called the
writer and said: "Let's make that thing continuous; let the
printing, washing and drying be done by a motor so that all
the boy needs to do is to put in the tracings, letting the prints
come out dry at the other end where an extra boy can trim
them."
After much sketching and discussion the continuous-printing
machine shown in the illustration was evolved. The writer
makes no claim to originality of design, but proposes to show
how with little expense and by using material already at hand
any blueprint machine of the type mentioned can be trans-
formed into a machine of 100 per cent, efficiency. The general
scheme only is shown, as space forbids details.
We procured a small slow-speed motor which we belted to a
set of cone pulleys so arranged as to provide minute speed vari-
ations in order that the printing speed of the paper might be
accommodated. The glass cylinder from the machine was
mounted in a cradle formed by four felt-covered rolls of wood,
which were driven at a common speed by means of bicycle chain
and sprockets, the sensitized paper being therefore at rest in
22 AMERICAN MACHINIST SHOP NOTE BOOK
respect to the cylinder and showed no tendency to slip. The
tracings were inserted from below at the front of the machine
and the entire width of the cylinder was kept covered.
In the wash tank the paper was sprayed from the under side
by means of four pipes which were drilled with a row of small
holes throughout their length. The spray coming from below
caused considerable motion of the water and made the washing
practically perfect, which fact was demonstrated by the non-
fading qualities of the print when exposed to strong light.
The drier was made up of thin wood slats riveted at their
ends to rubber belts. These belts ran over pulleys large enough
VARMTOR
^
FIG. 10 AN IMPROVED BLUEPRINTING MACHINE
to admit a steam radiator of about 100 sq. ft. area between the
running parts of the belts, the radiator being set at an angle
of 45 deg. with the wash tank so that the drip would run back
into the tank. The drier was in fact a belt conveyor, as the wet
prints would not stand any pulling. After passing over the
drier the tracings were allowed to fall into a large box, and the
blueprint was cut up into 6-ft. sections for trimming.
One might think that this machine would need a very intelli-
gent person to run it, but the fact is that two colored boys at $4
per week ran it nicely.
On one occasion there was a lot of tables to print for new shop
standards, etc., on 18 x 24-in. sheets. After eight hours' work
DRAFTING AND DESIGN
23
the prints were counted and there were 996. Thus the capacity
of "Big Liz" had been nearly quadrupled.
GUARD FOR DRAWING TABLE
The illustration shows a simple means for eliminating a source
of continual annoyance due to the rolling off of drawings and
FIG. 11 A GUARD TO KEEP DRAWINGS FROM ROLLING OFF THE TABLE
tracings from the table. The stock used was 1-in. oak strips
fastened by countersunk screws.
FIG. 12 PAD FOE BLEACHING BLUEPRINTS
24 AMERICAN MACHINIST SHOP NOTE BOOK
BLOTTING OUT DIMENSIONS ON BLUEPRINTS
It is frequently necessary to blot out dimensions, etc., on blue-
prints and bills of materials. A good way to accomplish this is
to cut a pine block Fig. 12 so its dimensions will be about the
same as the space which it is desired to blot out and fold a strip
of blotting paper over this end in the manner indicated in the
illustration, and fasten with thumb tacks. When moistened
with the bleaching solution and pressed down squarely on the
print it whitens the spot exactly where it is required.
EXTENSION FOR USE IN DRAWING LARGE RADII
To avoid the necessity of removing a drawing from the board
to permit the scribing of arcs whose centers lie beyond the edge
of the board the extension here illustrated has been devised.
FIG. 13 EXTENSION FOB DRAWING LARGE RADII
Two pieces of wood and a small clamp are all that is required.
A suitable width for both pieces is 2 in. The upper piece, which
can be made 12 in. long, should be a trifle less in thickness than
the drawing board at the base to enable the clamp to grip the
DRAFTING AND DESIGN
25
board. Both edges and the under side of the extension should
taper toward the outer end in order to lighten it and give it a
better appearance. A hole is bored through both pieces, after
they are fastened together for the clamp to slide in easily. It
will be seen that nothing projects above the drawing surface
except the upper part of the clamp and that no difficulty will be
experienced in drawing radius lines with trammel points or
beam compass.
SIMPLE ELLIPSOGRAPH
The ellipsograph here shown will save you time and money,
when you try to lay out elliptical templets, dies or anything of
the sort. It is so simply made that the illustration is self-ex-
FIG. 14 -COMPONENT PARTS AND ASSEMBLED ELLIPSOGRAPH
planatory. The pencil protector can be bought for 2c. A com-
mon pencil is always handy. A piece of catgut string (non-
elastic), a ring and wheel and two setscrews complete the
instrument.
SECTION II
PATTERNS AND FOUNDRY
FUSIBLE METAL FOR SOLDERING
SOME time ago, while doing pattern work, I received orders
that the lead figures, or pattern numbers, should be attached
with soft solder. The only solder available at the time was half
and half. I attempted to use it, but soon found that the lowest
heat which would cause it to flow was sufficient to melt or
bring the figures to a soft spongy state in which they could not
be moved.
I was about to give up in despair when I happened to remem-
ber a small piece of composition that had found its way into the
corner of my tool box. It was one of those little curios that all
mechanics, while drifting from place to place, pick up, only to
toss into some obscure corner, little dreaming of the important
uses to which such things may be put at some future time and
this was one of those times. This piece was fusible metal, a
composition of bismuth, lead, tin and cadmium, and had a melt-
ing point of 60 deg. C., or about 140 deg. F.
The pattern was heated and tinned in the customary manner,
except that the fusible metal took the place of solder. I sur-
prised my shopmates by spreading the melted solder with my
bare fingers and also used my fingers to align the figures, which
remained perfectly hard at this low temperature.
Anyone who has tried to solder sheet zinc for the first time
will remember how, with an iron too hot, a large hole is melted
in the article being soldered. This trouble is eliminated with
fusible metal, as the temperature required is much lower than
the melting point of zinc.
Several good formulas for fusible metal may be found in the
"American Machinist Handbook/'
26
PATTERNS AND FOUNDRY
27
PATTERNS FOR WORK WITH PROJECTING
MEMBERS
The tendency nowadays is to simplify patterns for the molder.
Assuming that the strips A, B and C are about ^ in. in
thickness and the body holding these strips is 2^4 in., I would
make this part of the body in two pieces, parting the pattern at
D with a narrow guide at E.
FIG. 15 IMPROVED PATTERN
In making the pattern in this way the body could be drawn
from the mold, leaving the part with the strips A, B and C in
the mold. After drawing the main body from the mold, this
part with the strips can then be moved back into the opening
left by the main pattern, and then withdrawn all in one opera-
tion. Making the pattern in this way would not require any
great amount of skill on the part of the molder.
BREAKING UP CAR WHEELS
A large number of 24-in. car wheels were broken as follows:
A piece of nickel steel 2 ft. long was turned tapering % in. per
ft., 3 in. and 4V6 in. at the ends. The bore of the wheels was 3*/4
to 4 a /4 in. The wheels were placed in a 9-in. hydraulic wheel
press, the tire side next to the ram, and the taper mandrel forced
into the bore.
It required from 30 to 50 tons to split the wheels into pieces
28 AMERICAN MACHINIST SHOP NOTE BOOK
of suitable size for a small foundry to handle. The time re-
quired was about 5 min. per wheel.
TOOL FOR DRIVING BRADS
The tool illustrated herewith is for driving brads in places
where it would be difficult to use a hammer. The sectional view
shows all parts lettered.
FIG. 16 BRAD DRIVER FOR PATTERNMAKERS
The plunger or driver A slides in the case B. The spring C
holds the driver up, leaving the opening H in the case to intro-
duce the brad, which is attracted and held by the plunger point
F, which is magnetized. The length of plunger movement is
regulated in each direction by the slot G in the case B and the
stop pin E. This tool is a most convenient one for the pattern-
marker's tool box.
ADVANTAGES OF PLATE PATTERNS
My experience with metal plate patterns is somewhat limited.
I have had considerable to do with the making and the molding
of plate, or match-board, patterns made of wood. All, or nearly
all, of these were intended for what were termed season, or
model requirements and extras for stock and repairs. For the
production of these castings wood plate patterns served the
purpose.
Many of the troubles with plate patterns made of wood can
be attributed to the patternmaker's limited knowledge of what
is required and what constitutes a practical and well-made pat-
tern. For example, I have seen plates made % in. in thickness
with plain flat battens at the ends, fastened with wire nails only,
PATTERNS AND FOUNDRY
29
the pattern varnish-finished in a slipshod manner. The reason
given by the patternmaker was that a thin plate is light for the
molder to handle and if made thicker the flask pins would not
reach through, which is a rather lame excuse for spoiling an
important and expensive piece of work.
I apply at least three coats of varnish to each half-pattern,
also the board, before assembling the parts of the board. The
width and length dimensions of the board are determined by the
size of the flask that is to be used. The thickness I make 1 in.,
never less. I use cherry wood in the construction of both pat-
terns and match board. The shape, dimensions and assembled
batten, fastened with glue and screws, are shown in Fig. 17.
FIGS. 17 AND 18 METHOD
L.
OF SETTING THE BATTENS AND A SAMPLE MATCH
BOARD PATTERN
Assembling and Matching. My method of assembling and
matching the half-patterns on the plate, as shown in Fig. 18, is
not common in pattern shops, but it is a simple way and practi-
cal. A sheet of drawing paper a little larger than the board is
fastened with thumb-tacks to one side of the board. The paper
is carefully trimmed flush with the edges of the board. The
half-patterns are placed on the paper in their correct positions
and temporarily fastened with fine wire nails driven through the
patterns, the paper and into the board about a /4 in. In other
words, these nails are nothing more than dowel pins.
With a knife made pointed and sharp, the paper is cut through
30 AMERICAN MACHINIST SHOP NOTE BOOK
along the edges of the patterns. If this job is carefully done,
the sheet of paper can be lifted away from, the patterns and the
plate, leaving the patterns and the paper under the patterns
fastened to the board. Each half-pattern, the plate and the
paper should be carefully marked in a way that will insure the
return of the patterns and paper to their correct and relative
positions on the board. The paper is transferred to the oppo-
site face of the board, flush with the edges; the match halves
of the patterns are placed in the holes in the paper and fastened
in the way described above.
The job is now ready for the final fastening of the patterns to
the board. The patterns are removed from the board, a coat of
thick shellac is applied to the joint face of the patterns, and
while the shellac is fresh, the pattern is securely clamped to the
board and fastened with fine wire brads. When the pattern is
finished, it is given a last coat of shellac.
The holes are cut and fitted to suit the pins on the flask that
is to be used on that special job. Do not be guided by templets
or measurements. See the flask; notice its condition. A good
plate pattern and a rattle-trap flask do not work well together.
Store your plate pattern on end in a special box made for the
purpose. Wherever the pattern goes this box goes with it and
saves much trouble.
CORE BOX DOWEL PINS
We have five plants situated in different locations. Four of
these plants are using taper dowel-pins in core boxes and claim
that they are the best and most satisfactory.
I claim that a straight dowel pin is the only correct pin to use
for core boxes and will produce a more perfect core. I back this
up for the reason that our foundry has less imperfect castings
returned to them due to imperfect cores than any of the other
plants. If a straight dowel pin is used, any particle of sand in
the hole will be pushed through by the pin and the box allowed
to close tight. If a taper dowel pin is used, any particle of sand
left in the taper hole will stay there and the core will not be
perfect, owing to the fact that the core box will not come to-
gether. This also applies to iron core boxes where the pin is
driven through one-half of the core box. I also claim that it
PATTERNS AND FOUNDRY
31
takes more time to equip core boxes with taper dowel pins, con-
sequently, they are more expensive.
PATTERNS FOR LARGE BEARING CAPS
I was working for a large manufacturing company, who up to
this time, had been providing lubrication for the large bearings,
by drilling and countersinking the caps for the bearings. It was
decided to provide oil pockets or wells on all of the various
bearings, and as their product included many styles and sizes
of machines, and many sizes of bearings, it appeared to be some-
what of an undertaking. However, the drawings were all
changed, and orders sent to our patternmaker to change the pat-
tern to provide for an oil pocket to be cast integral with the caps.
FIG. 19 THE LEAD PATTERN AND ITS APPLICATION
This is the way the patternmaker went about the job. He
selected the largest cap and made a pattern A, Fig. 19, of wood
of the oil pocket.
Then he made several molds, B, of plaster of paris and poured
enough lead castings at one heat for the entire lot of patterns.
The lead castings were fastened to the caps by brads, as shown
at C; the lead bending to the contour of the wood pattern very
readily. When he wished to provide for a shorter cap he would
simply cut out the required amount from the center and join the
ends, as shown at C. The lead was far more durable than wood,
to say nothing of the saving of time and labor, if the usual
method had been followed.
32 AMERICAN MACHINIST SHOP NOTE BOOK
CASTING A STEEL WORM
In Fig. 20 is shown a worm that was used in bottom-dumping
coal cars. The worms were steel castings, approximately 4% in.
in diameter and 9^4 in. long. They were made a loose fit for a
square steel shaft by which they were turned when dumping the
bottom of the car. As very little power was required, they could
be made fairly light. They were cast entirely in dry sand cores,
FIG. 20 ASSEMBLED AND DISASSEMBLED VIEWS OF WORM PATTERN
the boxes being constructed of hard wood, metal lined. The
worm pattern was of cast iron, fitted with a babbitt nut at one
end. The cone-shaped pieces, in the assembled view, are prints,
the core box for these being shown at the top in the disassem-
bled view. After being rammed, the worm was turned out and
the box separated, being held together with two clamping bolts.
Locating lugs were provided on the end and center cores so that
they could be placed accurately in relation to one another.
TURNING SMALL BOSSES FOR USE IN PATTERN
WORK
The following has been found a simple and quick method of
turning bosses from 2-in. diameter down to the smallest size used
on jig and fixture work for small parts of machinery.
In the illustration the wooden chuck is shown with the stock A
glued thereon, and also shows the different steps followed in the
method.
The order of procedure is as follows : True up the diameter
of the stock A to the size of the fillet required and face off the
stock. Mark off with dividers the circle B, which is the true
diameter of the boss. Gage with marking gage the required
PATTERNS AND FOUNDRY 33
height or thickness of the boss, and this line should be gaged
%4 in. deep. Turn diameter and fillet as shown at D. The next
operation is to cut off the boss if no hole for a dowel is to be
drilled in the latter. To cut off, take cutting-in tool (Vs-in.
chisel) and using gage line as guide, cut into small enough diam-
eter to break off as shown at E.
If it is desired to use the boss as a loose piece (using center
dowel as shown at F) first, after turning, take diamond point
tool and turn small countersink in the center of the boss, which
should be turned exactly true as shown at G. Next using the
FIG. 21 TURNING SMALL BOSSES FOR PATTERNS
countersink as a center for a twist drill, bore a hole to the depth
required. It is needless to add that the hole should be drilled
before cutting in for thickness of the boss. Bosses up to 1^-in.
diameter, and in almost any thickness, can be turned in the fol-
lowing manner without moving tool rest from its original posi-
tion: First, set the tool rest to proper position for turning
diameter ; second, face off the end of the stock ; third, set dividers
to radius of circle, and setting a tool across tool rest as shown
at H, locate center and scribe circle. After this operation pro-
ceed in the manner previously described to the conclusion of the
job.
RAPPING PLATES FOR PATTERNS
Some patternmakers might call the following an expensive
way of attaching the rapping plates to a pattern when only a
34 AMERICAN MACHINIST SHOP NOTE BOOK
few castings are wanted, but rapping plates are only put on very
large patterns and standard patterns from which a large number
of castings are to be produced.
Attaching a single plate with screws to a pattern which is thin
in section, is a rather difficult job for the patternmaker, as it
soon works loose. The proper method is to put two plates on
thin patterns in the manner shown in the sketch. The plates
come in pairs: plain holes in one, tapped holes in the other,
secured with brass screws screwed into the wood and plate.
PATTERN
-.Plate
-Tap for Screws PATTERN-
FIG. 22 RAPPING PLATE FOR THIN PATTERNS
The writer suggests to makers of rapping plates that stock
plates be made with holes for wood screws in the outer circles ;
the inner circles having one hole for rapping and one tapped
hole for lifting. To attach the plates more securely, without
increasing their size, they should be made with four holes in-
stead of two for the wood screws, thus doubling the security of
the plate to the pattern when only one plate is put on. The
zigzag position of the holes prevents splitting the wood.
A PATTERN PROTECTOR
While visiting a local firm recently I was somewhat interested
in the way the foreman patternmaker " armored" his patterns,
which I believe is worth copying in other shops. The method
PATTERNS AND FOUNDRY 35
adopted may be understood from the illustration, which is from
memory. As will be seen the faces A and B are covered with
thin sheet-iron plates, also the faces C and D on the boss, while
the two core prints are made of mild steel.
This method adds considerably to the life of the patterns with-
out adding the weight usual with iron patterns. It saves the
FIG. 23 A PATTERN PROTECTOR
molder a good deal of making up, which is necessary with a
wood pattern when it has been used a few times. This foreman
made no claims in this direction but he said : "It only protects
my patterns, and if they want iron patterns later on they can
have them. ' '
MARKING WOOD PATTERNS FOR THE PURPOSE
OF IDENTIFICATION
I have given quite a bit of study to the marking of wooden
patterns that are sent to the foundry, and have arrived at the
conclusion that I have found a new and cheap way of marking.
I had three common rubber stamps made with the company's
name on them in letters %, */4 and Vz in. in size and also bought a
common black inking pad.
After the pattern is finished and sand-papered, stamp an im-
pression on the pattern in any convenient place, then take com-
mon white marking chalk and rub it all around the impression.
Gently smooth the chalk over the impression with the finger
until it is entirely covered (this prevents smudging the impres-
sion when shellacking), then apply a coat of yellow shellac over
the impression. Be sure to use only one stroke of the brush, as
more might cause the ink to spread. After this has dried apply
as many more coats as the pattern requires, usually one more.
36 AMERICAN MACHINIST SHOP NOTE BOOK
The pattern can now be shellacked all over with black shellac,
painting around the impression.
This makes a very clear, cheap and lasting marking, and has
all the other methods that I have seen beaten 50 ways.
EFFICIENT HERRINGBONE GRATE PATTERNS
As I have had considerable experience in making patterns for
single- and double-angle herringbone grate bars for furnace and
boiler fireboxes, also for catchbasin grates in various designs,
my method may be an improvement on the one followed by many
patternmakers.
Cutting and fitting one at a time the bars to the side
frames is slow and tedious ; especially is this true in the making
of a herringbone grate pattern. One of several patterns for
catchbasin grates recently made will serve as an example and
will aid me to make clear the description of my method.
FIGS. 24 AND 25 PATTERNS FOB CATCHBASIN GRATE
A corner of the assembled pattern is shown in Fig. 24. The
frame FG is made and varnish finished. The angle bars B are
made and varnish finished on the flat sides only. In Fig. 25 is a
board 1 in. thick and 6 in. wide, planed flat and true on one
face. Strips of drawing paper 1 in. wide are fastened with glue
at the edges of the planed surface; and construction lines are
drawn across the face of the drawing paper, indicating the
angle and position of the bars and the spaces, The bars are
PATTERNS AND FOUNDRY 37
''spot" glued to the drawing paper, wide face down. Remem-
ber, a spot of glue ; a "slobber" of glue will spoil the job. When
the glued spots have set, lay the frame on the ''board side" of
the bars, and mark along the inside edge. Tilt the band-saw
table at the same angle as the inside of the frame, and band-saw
along the line. If the marking and sawing are carefully
done, the bars will drop into place in the frame without further
fitting.
Varnish (not glue) the ends of each bar; assemble and fasten
with wire nails, first drilling small holes to receive the nails.
This is important. To remove the board, start each "spot,"
using a wide chisel and hammer. A light, smart tap will do the
job. Plane and finish the edge surfaces.
The following shows a method of making double herringbone
grate bar patterns.
After having planed the stock for both the crosspieees and the
frame, the block A, Fig. 26, was made to the exact size of the
inside of the bar, the ends being tapered to fit the frame and the
angled faces to fit the cross-pieces.
The pieces C were then made to the same length and taper as
A, but about % in. higher. These pieces are merely for addi-
tional guides for the back-saw. After mounting pieces A and C
on the block B, I sawed the slot in the center and the sawing jig
was ready. I then took D, one of the strips which was made for
the cross-pieces, and in the manner shown, cut as many right-
hand pieces as there were crosspieces in the bar; I then cut the
same number of left-hand pieces.
These pieces were then taken to a surface plate G and all glued
in pairs as shown at E, Fig. 27. While the glue was setting the
frame F, Fig. 28, was made.
After the crosspieces had set, they were nailed both ways at
the point (a scrap of the crosspiece strip being used to hold
them in the vise), glue-cleaned and well shellacked. They were
then put on the jig again and cut to the exact length of the
block A, Fig. 26.
I have found that the back-saw, if carefully used, will make
truer, cleaner cuts than the band-saw, and when the pieces C
are located on the jig, the sawing of the ends is comparatively
easy.
When the crosspieces have all been cut to length, the frame F
38 AMERICAN MACHINIST SHOP NOTE BOOK
is turned upside down on the surface plate, as shown in Fig. 28,
and the crosspieces glued in as shown at E.
Care must be taken to see that the first piece is set square,
the others can then be set in like so many dominoes, proper
spacing being accomplished by using little squares of wood the
size of the required opening.
FIGS. 26, 27 AND 28 A METHOD OF MAKING GRATE PATTERNS
After approximately five crosspieces have been set in, the
little squares that were used to space the first two can be picked
out with a scriber and used again. Then the pieces that were
used in the second space can be taken out, thus proceeding down
the bar.
After the glue has properly set, the clamps are removed and
each crosspiece is first drilled, then nailed in the frame. The
PATTERNS AND FOUNDRY 39
frame is then filleted with %-in. fillet, finished and shellacked.
In this manner I have made bars from 18 in. to 6 ft. in
length, and have cut from $5 to $15 per bar from the former
cost of making.
SECTION III
FORGE SHOP, HARDENING AND
TEMPERING
STANDARD MARKING FOR DISTINGUISHING THE
VARIOUS STEELS
THERE is one thing in connection with steel which I think could
be used to advantage throughout the country, and that is a uni-
versal color scheme for the marking of the various grades so that
when steel is received by the consumer, jobber or dealer he would
at once know machine steel from tool steel and tool steel from
high speed, etc.
We have adopted certain markings, and these, with the rea-
sons for our choice, are given below :
All machine steel and screw stock we mark white, as this is
the general custom for low-carbon steel. Chrome-nickel and
other alloy steels we mark with yellow. High-speed steel we
mark red, as this seems to be so closely connected with the under-
standing of high-speed steels. This leaves for tool steel, the
other principal color, blue.
Then, if you have a steel that is halfway between any of these ;
for instance, an air-hardening steel that is neither tool steel nor
high-speed, mark it blue and red. If you have a high-grade
machine steel that is neither machine steel nor tool steel, mark it
blue and white and the same with other combinations.
If this idea could be adopted by all the steel plants, it would
save a great deal of confusion and expense. People constantly
come to us asking whether stocks they have are tool steel or high
speed, and even ask us to differentiate between tool steel and
machine steel. This is a problem that is very difficult to solve
unless a person is familiar with the various grades.
Of course from our experience we can quickly tell, but the
ordinary supply house, and in fact most factories, cannot tell the
40
FORGE SHOP, HARDENING AND TEMPERING 41
difference. With some such scheme of marking as the fore-
going, however, all this trouble would be eliminated.
We mark the full length of the bar in stripes if it is a com-
bination steel, but in a solid color if a known standard grade
that agrees with the standard market. If we have any short
ends they are always marked.
FORGED HIGH-SPEED BITS
I have had the experience with bits forged from high-speed
steel that the lightest cut would take the edge off and ruin the
tool.
To remedy this defect, I reharden them and draw the temper
to a very light yellow, and. with that temper it stands up just
as well as the original piece did before it was hammered out.
OXYACETYLENE WELDING HIGH-SPEED STEEL TO
MACHINE STEEL
Owing to the high cost of high-speed steel, the practice of
welding high-speed steel tips to machine-steel shanks is of inter-
est to manufacturers. Welding a high-speed steel tip to a ma-
chine-steel body for cutting off tools for automatic machinery
has been more or less a difficult problem, owing to the shock the
weld has to stand from the constant chatter of the stock against
the tool.
Take two pieces of high-speed steel A, % in. square by 2 in.
long, and grind a 3 /i-in. radius on the end of each. A rough
machine-steel body is milled at both ends as illustrated at B.
The parts are assembled and put in the jig C, which is made
from two pieces of % x %-in. machine steel D and E. They are
fastened with two clamps, F, made of flat steel held by a /- or
%-in. U-bolts G. Wing nuts should be used if at all possible, as
they are easily and quickly adjusted.
The reason for using the jig is that when the flame of the
torch is directed on the places to be welded it heats the tips and
the body of the blade very quickly and causes the steel in the
blade to expand before the jig has time to get very hot. These
two bodies, when heated until they run at the weld, are forced
together by their expansion, resulting in a better weld,
42 AMERICAN MACHINIST SHOP NOTE BOOK
The work should be removed from the jig quickly and placed
in powdered lime or bar sand, to prevent chilling and the for-
Awembly showing Blade
clamped in
Block for Holding Blade
(MACHINE STEEL)
Contour of Blade after Welding
t
Contour of^fmished Btade
16 Threads per
Inch.U.S.Std
Right Hand
Clamp (COLD~K>UD STEEL)
FIG. 29 JIG FOB WELDING HIGH SPEED STEEL TIPS TO MACHINE-STEEL
BODIES
mation of hard brittle spots in the weld, which are difficult to
machine even after the regular annealing process.
FORGE SHOP, HARDENING AND TEMPERING 43
ARC- WELDING HIGH-SPEED TOOL TIPS
Arc-welding was brought prominently before the public by its
use in restoring the broken engine castings of the interned Ger-
man ships a short time ago. When breaking these castings the
Germans thought they could not be repaired and that it would
require a year or more to replace them. But even before the
ships could be otherwise overhauled and made ready for trans-
port service all the broken castings had been repaired and were
as good as new. This achievement impressed the value of arc-
welding on the minds of many shop managers, and in several
plants castings and other parts of apparatus which in the past
FIG. 30 WELDING HIGH-SPEED TIPS ONTO MILD-STEEL SHANKS
would have been scrapped as hopelessly damaged are now per-
fectly restored by the arc-welding process at small cost and
great saving of time.
One large manufacturer working on munitions has installed a
Westinghouse arc-welding equipment for the sole purpose of
making tools for turning shells. Ordinarily these tools are made
from high-speed steel and cost about $12 each. This manufac-
turer uses high-speed steel for the tip of the tool only, welding
it to a shank of carbon or machine-steel, and in this manner the
tools are produced at a cost of $2 to $4.
For several weeks this plant has been turning out 240 welded
tools a day, the men working in shifts of four, which is the
capacity of this outfit.
The equipment consists of a 500-amp. arc- welding motor gen-
44 AMERICAN MACHINIST SHOP NOTE BOOK
erator with standard control panel, and three outlet panels for
metal-electrode welding and one special outlet panel for the use
of either metal or graphite electrodes. The special panel is in-
tended to take care of special filling or cutting processes that
may be necessary, but ordinarily it is used in the same manner
as other panels for making tools. These panels are distributed
about the shops at advantageous points.
For toolmaking, which involves the hardest grades of steel, a
preheating oven is used, not because it is necessary for making a
perfect weld, but because otherwise the hard steel is likely to
crack from unequal cooling and also because preheating makes
it easier to finish the tool after the welding process has been
completed. For ordinary arc-welding operations the preheating
oven is never used.
ECONOMIZING HIGH-SPEED STEEL WITH THE
ELECTRIC BUTT WELDER
The increased cost of high-speed steel has made it necessary
to economize in its use in the shop. One way to do this is to
put a short tip of high-speed steel on a carbon-steel shank. Va-
FIG. 31 BUILT-UP TURNING TOOL FIG. 32 BUILT-UP REAMER
rious methods of attaching this tip have been attempted, such as
brazing, and also welding with the oxyacetylene torch.
The Reo Motor Car Co., Lansing, Mich., is using Winfield
butt-welding machines for affixing the high-speed steel tip to
carbon-steel shanks for cutting tools. The current required is
4 to 10 volts and 400 to 500-amp., depending upon the size of
the tool section being welded. In Fig. 31 is shown a bent turning
tool that has been made with the electric butt welder. The
carbon-steel shank A and the high-speed steel tip B are first cut
to length. For a bent tool this tip is made about 1W in. long.
On a straight tool the tip is usually about 3 in. long. A piece of
tin is spot welded over the joint of the two steel sections to hold
FORGE SHOP, HARDENING AND TEMPERING 45
them in alignment, as shown at C. The tool is then held in the
jaws of the butt welder, and the two pieces of steel are united.
The average time required to make the butt weld is approxi-
mately 1/2 minute.
One of the tools as it comes from the machine is illustrated at
D. The joint is ground off, as shown, by the tool E. The tool
may be either bent or left straight, according to requirements.
A bent tool may be seen at F.
At this factory, reamers have been built up in a manner
similar to that described for turning tools. In Fig. 32 is shown
the making of a reamer from the loose shank and tip to the
ground and fluted reamer. For reamers the high-speed steel tip
is approximately 2 in. long.
For the annealing operations that follow the dressing of the
joint and subsequent bending the tools are put into an oven at
1600 deg. F., where they remain for approximately 6 hours.
Then they are placed in lime to cool, remaining for from 7 to 10
hours. This process is merely a preventative against crystal-
lization and is followed by the hardening process. For this oper-
ation the tools are heated to approximately 2200 deg. F. and are
then quenched in kerosene or fish oil, being left in the liquid for
from 3 to 5 hours.
The tools and reamers made by this process are giving satis-
faction in service.
COST OF WELDED HIGH-SPEED TOOLS
The accompanying figures, from costs taken on a lot of 300
welded tools recently made, readily indicate the advantages of
COST OF 300 WELDED TOOLS
Labor :
Saw $2.00
Shape 3.00
Blacksmith 3.00
Pack harden 1.60
Oxyacetylene weld 22.00
Rough grind 8.90
Gas harden . 6.22
$46.72
Material, 320 lb., new cold-rolled stock 22.40
Total , , ,,,.,.,.,,,,,,.,,...,... $69.12
46 AMERICAN MACHINIST SHOP NOTE BOOK
tools with cheap steel shanks and welded high-speed steel cutting
tips taken from the scrap box. At a total first cost of less than
24c., a tool was made that replaced the customary $4 one in use
in most shops.
BRAZING STELLITE
I have noticed the various articles printed in the American
Machinist regarding the brazing of stellite to steel shanks. The
Haynes company discovered a method of brazing stellite to steel
shanks which is superior. By referring to Fig. 33, the reader
will notice that a thin web A is left on the side opposite the cut-
ting edge of the bit. This web is of course governed by the
width of the bit and should be chamfered, as shown at the point
B,'ai about a 45-deg. angle, and of a depth that is approximately
% of the total depth of the bit. The reason for leaving this web
is to insure plenty of copper in the joint prior to lifting the
tool from the fire.
FIG. 33 METHOD OF SETTING A STELLITE BIT
Place the stellite tip and the shank in the forge, allowing both
to soak in the fire and become white hot. Then place a thin
sheet of copper between the steel shank and the stellite tip,
applying borax freely. Bring the tool to a white or such heat as
will soften the stellite slightly. From time to time additional
copper should be melted either from a piece of copper tube or
copper sheet and allowed to flow in the chamfer B, being care-
ful to borax the joint freely before the copper is flowed in. In
this way the copper will run down and wash away the dirt, and
FORGE SHOP, HARDENING AND TEMPERING 47
at the same time exclude the air and do away with oxidation.
After the tool is brought to a point at which the stellite begins
to soften it should be removed from the fire and squeezed slightly
with a pair of tongs or any other convenient tool, such as a vise
or press.
This method will require some practice and the maker of the
tool should not be discouraged if his first braze is not a success,
as we have found that these tools are capable of standing any
strain up to a point of breaking the shank.
SOME HARDENING KINKS
Most of the articles on heat-treating and hardening are for the
fellows with up-to-date furnaces and pyrometers and all that go
with them. There is nothing for the little fellow who has only
a forge in which to do his heat-treating and hardening. Here
are a few kinks we have developed in a small toolroom where we
have only a forge for such work. A few requisites for a forge
are some pieces of channel iron, 6- and 4-in. sizes, say about 12
in. long, some good gas coke, a barrel of water and a tank of
quenching oil. There should be a wire basket that can be easily
lifted out. This is very handy and allows a number of pieces to
be handled at once.
High-Speed Steel Taps. High-speed taps are difficult to
harden because of the chance of blistering. The best method
we have found is to use a piece of heavy channel iron in the
fire, bank the fire around it and cover with a plate. Preheat the
taps in the channel iron to a good red heat, using a moderate
blast. Then with the poker make a hole in the fire under the
channel iron and shut off the blast. This gives a small retort
that is white hot. Hold the tap in this. It will quickly come
to a yellow heat and can then be quenched in oil. To keep the
tap from scaling, I use a compound of the following ingredients :
50 per cent, of corn meal, 20 of borax, 20 of common salt and
10 of crushed resin. When the tap gets a dull red heat, I put
it in the compound for a minute and then put it back in the
channel iron. This forms a coating that protects the threads
and is easily washed off, at the same time it permits the work to
quench quickly.
Carbon-Steel Tools. The same treatment can be used success-
48 AMERICAN MACHINIST SHOP NOTE BOOK
fully for high-speed cutters. I also use the channel iron for
hardening all carbon steel. If there are a number of small
pieces, they can be all put in together, with no fear of burning
them. To harden a long reamer, it is best to use a new piece of
channel iron or one that is perfectly straight. Lay your reamer
in the bottom and keep rolling it from side to side of the chan-
nel iron until you get the right heat. Then quench straight
down in the water, moving the reamer slowly up and down
until you feel that the steel has finished sizzling. Then take it
out and let it cool in a warm oil bath. With a little practice you
will be able to get the reamers nearly straight. Before harden-
ing anything round that lias to be ground, I drill a hole in the
end about % deep. After hardening I plug up the hole and
then have a soft center to help get the piece fairly true. Be
sure to plug 'the hole with a little putty before hardening.
A hard thing to make in the average small shop is a chuck
wrench of the box type. The average chuckmaker does not leave
enough room to permit a good heavy wall on the wrench. The
result is that when the machinist gives his chuck an extra tight-
ening, away goes his wrench. For box wrenches I have the most
success with chrome-nickel steel. To heat-treat it, bring it to a
good cherry heat and quench in oil until cold ; then draw to a
light blue.
HARDENING HIGH-SPEED STEEL TOOLS
We have experimented with the carbonizing treatment and
have found that it is very difficult to regulate the thickness and
uniformity of the skin. We have also found that the carbonized
portion has a tendency to lift away from the rest of the body;
and since the carbonizing extends over a considerable space of
time, there is a decided leaning to grain growth in the carbonized
section, which yields a very coarse and brittle edge. The in-
creasing brittleness with increasing carbon content also must
not be disregarded.
In the treatment of high-speed steel the first essential is to
have a heat in which the atmosphere is not of a decarbonizing
nature. Decarbonizing leads to oxidation, and oxidation causes
heavy scaling. Blower or compressed air or dry steam is a suit-
able atomizer, but an excess of fuel should be used to prevent
FORGE SHOP, HARDENING AND TEMPERING 49
excessive oxidation and scaling, which would prove ruinous to
small fine tools.
The method of heat-treatment described applies to all our
tools, from the smallest to the largest, which include heavy
formed milling cutters, punches and dies, circular formed tools,
taps and chaser dies. We have never been troubled with exces-
sive scaling or changing in size, and microphotographs show a
perfect, uniform, true hardness to the very center of the tool.
First, our tools are preheated to 1600 to 1700 deg. F. (the
greater the cross-section of the tool the higher the temperature)
in an overtired furnace in which oil is used as a fuel and steam
as an atomizing agent. This heat-treating shortens the length of
time for the hardening heat, which follows, and assures perfect
and uniform assimilation of that heat.
The temperature of the hardening furnace, which is similar to
the one used as a preheater, depends on the analysis of the steel,
which, of course, must be known before any heat-treatment is at-
tempted. The steels of lower tungsten content harden at much
lower temperatures than those which contain the higher per-
centages. Having worked on all brands of steel, we have found
that the temperatures can safely be included within the limits of
1950 to 2300 deg. F. The correct furnace temperature is essen-
tial, and the use of accurate, foolproof pyrometers equipped with
rare-metal thermo-couples cannot be too strongly advised. Even
in the small shop an expensive tool saved will more than offset
the entire cost of the equipment.
The length of time in the hardening heat depends wholly on
the size of the tool being hardened. It is essential to shorten
this period of time as much as possible, and the piece should be
allowed to stay in the furnace but a very short time after reach-
ing the determined temperature. Moving the piece around in
the furnace will promote uniform heating. Soaking at the hard-
ening temperature may be essential on the larger sections, but
should never be practiced on the smaller finer tools.
The universal quenching medium for high-speed steel is oil of
such character that prolonged use will not cause it to thicken,
for an extremely nonviscous mass must be used to insure the
speedy transmission of the heat from the tool to the bath.
The chemical composition of high-speed steel permits the use
of a higher tempering point than in ordinary carbon steels. It
50 AMERICAN MACHINIST SHOP NOTE BOOK
is essential to use the maximum temperature, for tempering will
preclude the possibility of cracking and will give a much tougher,
stronger tool. Most high-speed steels will stand a temperature
of 1000 deg. While it is not necessary to temper to this point,
it is strongly recommended to use a temperature of 600 to 700
degrees.
This method can be carried out in any muffle to semi-muffle
furnace, at the very front of which the preheating may be done
satisfactorily, where the temperature ranges within preheating
limits. For the hardening heat, it is only necessary to move the
tool farther back on the hearth, where the desired heat may be
obtained. Our loss by tLis method has been practically negli-
gible. We have handled the finest and most particular tools,
and from actual shop tests the efficiency of a tool heat-treated
in this way is far greater than that of the tool heat-treated in
any other way that we have ever used in our shop.
HARDENING FORMED HIGH-SPEED CUTTERS
Some time ago I had cause to experiment along these lines
and found that the results were not altogether satisfactory.
Tools were packed in charcoal in a cast-iron tube, placed in a
gas furnace and heated from cold.
Temperatures over 1900 deg. F. were found to fuse the out-
side of the tool, completely ruining its form. Temperatures of
1750 to 1800 deg. F. produced a satisfactory surface hardness,
but after the surface had been ground away the tool was not
hard enough to give good results. This effect I attributed to
overcarbonization of the steel. This also would account for the
tendency of the cutters to crack when left too long in the
furnace.
I found that by extremely careful heating according to steel
makers ' specifications, with special regard to the condition of
the atmosphere in the furnace, it was possible to obtain a fairly
high degree of hardness in a furnace kept at 2100 deg. F., with-
out damaging the surface of the tool. I did not, however, have
an opportunity of testing the actual performance of the cutter
in use.
I have also tried a powder (called "HeTzy" and supplied by
the Bennett Metal Treating Co., Elm wood, Conn.), that I under-
FORGE SHOP, HARDENING AND TEMPERING 51
stand has been used with success by makers of high-speed steel
cutters. The cutter to be hardened is packed in this powder and
thoroughly heated at a temperature of from 1700 to 1750 deg. F.,
then quenched in oil ; small pieces may simply be allowed to cool
off in the air. I tried regular lathe tools hardened in this way
and found that on cast iron and bronze good results were ob-
tained, but the tool failed when cutting tough alloy steels.
There appears to be some doubt as to whether high-speed steel
can be hardened successfully at low temperatures, when packed
in charcoal or similar powders, and claims to success should be
accepted only after tests have been made of the cutting powers
of tools so hardened against tests under similar conditions.
Another writer says :
I have been using high-speed steel with varied results since it
was first introduced and have tried a number of compounds
recommended to protect the steel from oxidation, with little or
no success until I tried coke dust. The coke is ordinary foundry
coke, and forming cutters treated in dust made from it come out
harder at a lower heat, are free from scale and pitting and will
do better work. The coke dust can be procured from the
screenings at the foundry or, better, take clean coke and grind
it in an ordinary rattler by adding some scraps of iron. The
finer it is ground the better results will be obtained.
Pack the cutters in an ordinary cast-iron box with a layer of
coke, then a layer of the cutters, and so on until the box is full.
Be sure to use plenty of coke. Heat in a furnace to 1740 to
1800 deg. F. for two or more hours, according to the size of the
work, and quench in a light tempering oil. A mixture of 10 to
1 of lard oil and kerosene works well. The coke can be used to
good advantage for pack hardening parts of machinery made
from low-carbon steels, also cast and malleable iron, that require
to be hardened on the surface. It may be necessary to add
ground bone or burnt leather for some parts that must have a
deeper and harder case than others.
Still another method is as follows :
It was found that cutters used for blocking gears would not
stand up under the feed required of them. After some experi-
menting on our part, it was easily seen that to eliminate break-
age the cutters must be drawn to toughen them, but not too
much to cause excessive grinding.
52 AMERICAN MACHINIST SHOP NOTE BOOK
The following method of handling gives good results: The
cutters are preheated six at a time, held as in Fig. 34, to 1550
deg. F. and then submitted to a heat of 2330 to 2380 deg. (ac-
cording to the amount of carbon) in the high-speed furnace.
The cutters, however, are not allowed to reach this heat, but are
handled faster by running it high. They are then plunged
into oil at from 200 to 400 deg. and either kept moving or the oil
circulated.
FIG. 34 CUTTEB HOLDER AND CURVE SHOWING RELATION OF DRAWING
TEMPERATURE TO HARDNESS
After removing the bolt, they are brought up gradually to
1050 deg., the drawing point, and cooled in oil. The curve
above shows the relation of other drawing points to 1050 degrees.
Cutters treated as outlined above will block out a bevel-gear
tooth 0.400 in. deep in 13 sec. that is, a 48-tooth bevel will
require 10 min. Under fair conditions, regarding hardness of
stock to be machined and the state of repair of the machine, 40
gears may be blocked at one grind.
REPAIRING A BROKEN CRANKSHAFT
We were recently called upon to repair the crankshaft of a
10 x 20-in. steam engine which operated the pulp grinders at the
local paper mills, it being important that the repair should be
made in the shortest possible time as the mill depended upon
this power unit for its supply of ground wood. A new forging
could not be obtained in less than three weeks, and as this delay
FORGE SHOP, HARDENING AND TEMPERING 53
was out of the question our only resort was to weld the broken
shaft.
The shaft was broken at A. and partially broken at B, as shown
in Fig. 35. We had an oxyacetylene welding outfit, and our first
idea was to weld the shaft as it was, which could have been done
at A, but the break at B was so located that it was impracticable
to scarf off the sides to secure a sufficient bonding surface for
the weld. We decided to cut the pin from the webs as at X
54 AMERICAN MACHINIST SHOP NOTE BOOK
and substitute a new one, and in order to save the time necessary
for turning the new pin after it had been welded in place we
decided to finish it complete beforehand. This meant that the
pin must be held firmly in perfect alignment with the main
parts of the shaft during the welding process.
To do this we made four V-blocks with projecting lugs to
match the groove in our planing machine, and another block of
the same dimensions without the lug. As an extra precaution
we turned the new pin Me in. oversize with the idea that we
would have enough stock for re-turning in case anything hap-
pened to move the parts out of alignment during the welding
process. At the same time we calculated that if the parts did
come square it would only be necessary to rebore the crankpin
box to fit the oversize pin, which would be a small job compared
with re-turning the pin.
After the webs were cut off each was scarfed at an angle as
indicated by the dotted lines at C and C. The whole was then
assembled on the planing-machine, table D being fastened first;
then the new pin was placed in its V-block and carefully lined
up with the main parts of the shaft.
Two finished strips E were then bolted to the table to form a
guide for the V-block holding the new pin, as it was thought that
this block would have a tendency to move when heat was ap-
plied. To take care of this expansion the distance from center
to center was made about VIQ in. less than the required throw.
Some of the straps are omitted for the sake of clearness. As-
bestos paper and firebrick were placed underneath and around
the pin and webs in order to protect the planing-machine table
from the heat.
The welding was now started, heat being applied first to one
side and then to the other with the idea of heating the webs uni-
formly. The building-up process was carried out in the same
manner by alternating the torch from one web to the other to
avoid distortion as much as possible and thus make it unneces-
sary to re-machine the pin and possibly the whole shaft. After
one side of both webs was welded the whole was turned over and
the process repeated upon the other side. During the welding
process the bolts holding the pin were eased off slightly in order
to allow the block to move outward in the guides.
After the weld was completed and the shaft had cooled suffi-
FORGE SHOP, HARDENING AND TEMPERING 55
ciently it was put upon centers, tested for accuracy and found
to be correct in every way. The engine has now been running
approximately 60 days since the repair and is giving complete
satisfaction.
It will be noticed that the new portion of the web was made
wider than the original and resulted in a much stronger web,
the middle section being built out to 7 in. instead of 5 as in the
original.
REPAIR WORK FOR STEAM-HAMMER PISTONS
It seems to be a view quite generally held among a great many
hammersmiths using steam hammers that, when any accident
occurs to the piston of the hammer, causing it to break, nothing
can be done except to replace the broken part with an entirely
new piston, and that pistons to be serviceable must be forged out
of one piece of steel. So this practice is often followed, no
matter how large the piston head is; in many cases an enor-
mously large billet is required to be of sufficient diameter for
the head. For the past two or three years we have been dis-
proving- this theory by the continued use of several repaired
pistons and heads, which are giving remarkably satisfactory
service.
Several years ago the piston of our 1500-lb. steam hammer
broke off several inches below the head. For such a break the
suggestion of a weld would really be absurd, for the continued
percussion stresses would quickly open the best of welds, whether
forged, thermit welded or acetylene-torch welded. The piston
head is about 12 in. in diameter, nearly double the size of any
billet that we then had available, but we did have in the scrap
pile a number of old high-carbon steel car axles that were
sufficiently large to machine up to the diameter of the piston.
The manner in which the repair was made is illustrated where
the parts C and D are shown. The broken stub of the piston was
sawed from the head, and the latter was bored out and threaded
to a diameter equivalent to that of the piston rod, a large fillet
space being cut off the bottom edge to accommodate a correspond-
ing fillet-like collar provided on the piston rod. The sketch of
the piston rod also shows the precaution taken to provide a
fillet, since it seemed possible that if there were any tendency
56 AMERICAN MACHINIST SHOP NOTE BOOK
toward breakage of this new rod, it would occur at this point,
which takes the full side twist of the head.
The rod was tightly screwed into the head; the threaded sec-
tion was of sufficient length so that it projected slightly above the
upper side of the head, and this projection was battered and
peened over to prevent all possibility of the rod working loose.
The repair was successful, and the hammer has been in constant
daily use for over two years.
On two of our other steam hammers we have had occasion to
bore out the cylinders, on one for excessive wear, on the other
FIG. 36 STEAM HAMMER PISTON REPAIR
for the removal of deep grooves cut by a broken piston ring.
Both times the amount of material removed from the* inside walls
was so great that there was no possibility of using the old piston
heads, as they formerly were, by simply providing new rings.
Each of these pistons was turned down to 2 in. less diameter,
leaving two ribs or bands, to act as keys, extending completely
around their circumference, as shown at X in A. A shrink band
of sufficient width and thickness to allow for the increased diam-
eter of the cylinder was welded up as shown at B. The interior
of this band was bored out, and the two grooves at T were pro-
vided, V& x % in., to match the bands that were left on the head.
FORGE SHOP, HARDENING AND TEMPERING 57
The bore of the band is left %a in. less in diameter than the head,
to give plenty of pressure upon shrinking.
When thus made, a band will expand enough when heated to
a good red so that it will pass over the ribs of the thickness men-
tioned left on the piston head. The ribs and recesses are given
a little taper on their edges, as indicated in the sectional views
at R and S, so that there will be no chance for the band to hang
on any of the edges of the ribs when it should be shrinking
tightly into place. These sizes for ribs and grooves apply for
heads that are left at least 10 in. or more in diameter; smaller
pistons must have proportionately smaller ribs, grooves and
shrinkage allowance.
After the band is shrunk on the head, the outside is turned
off to match the inside diameter of the rebored cylinder, and
new ring grooves are turned in its outside surface.
In making up new rings for such a piston, one point worth
remembering, which probably must be explained to the machine-
shop foreman, is that rings for a steam-hammer piston, unlike
those for a plain steam engine, are not made of cast iron, but
must be turned from a forged-steel band that the forge shop
should have prepared while the other work is being done.
Cast-iron rings are really most unsuitable, because the jar of
the hammer in service will break up rings of this material in a
few days ; and these pieces will start in at once to score the in-
side walls of the cylinder.
The largest hammer that we have so far had occasion to re-
pair in this manner is rated at 2500 lb., but both of those that
we have so repaired have been in service for a long time with no
signs to date that the rings are either loosening or slipping.
RECORDING CYLINDER AND PISTON REPAIRS
In the table, Fig. 37, is shown a method of keeping a record of
steam hammer and cylinder repairs. It is also applicable for
use in other classes of work, and provides a convenient method
of keeping a repair record up to date. This record may be kept
in any desired or convenient place on the cylinder, by space
lined horizontally and vertically. On the horizontal lines are
noted the dates of the repairs, while the vertical sub-divisions
contain dimensions of the cylinder, piston, piston rings and
58 AMERICAN MACHINIST SHOP NOTE BOOK
length of piston rod after each repair job ; dimensions B and C
refer to cylinder bore and piston-ring diameter respectively.
For example, in B column it is seen that on Sept. 14, 1914, the
cylinder was bored to 14% in. and on Mar. 6, 1917, to 15 in.
Records are similarly kept of repairs made on piston heads,
piston rings and also on the piston rod; as the anvil base is
always set on wood, which allows it to settle somewhat, provision
is made to record the increased length of piston rod as required.
A method of attaching the piston head to the piston rod is
shown in the illustration. We have used this method for a
period of about three years with excellent results, and on ham-
mers ranging from 2000 to 6000 pounds.
A
B
C
D
Sept 14,19/4:
*6)
14^
~
70?
M<?Kh 6,19/7
*'
Ib"
JS&
MS*
FIG. 37 RECORDING CYLINDER AND PISTON REPAIRS OF (STEAM HAMMERS
The piston rod is tapered to fit and extend through a tapered
opening in the piston head. The piston head is heated and
shrunk on the rod, and the rod then well riveted.
The hammers referred to are probably worked as hard as any
that might be found. During the period of three years they
have been in service, they have operated practically without
interruption 115 hours per week. The material hammered was
of carbon and high-speeM steel, neither of which yields readily
under the hammer, especially the high-speed steel, and this con-
stituted about 20 per cent, of our hammer work.
BALL-JOINT PISTON ROD FOR STEAM HAMMER
We were having a great deal of trouble with the breaking of
piston rods in our steam hammer, and the breakage appeared to
be caused by the larger dies striking at one side which caused
the metal of the rod to crystallize. We had tried different kinds
of steel without satisfactory results and at last decided to try
FORGE SHOP, HARDENING AND TEMPERING 59
the ball- joint rod as shown in the accompanying illustration and
that seems to have eliminated the trouble.
FIG. 38 BALL JOINT FOR STEAM HAMMER PISTON ROD
A SPRING-HEATING FURNACE
The accompanying illustration shows a furnace for heating
and tempering the leaves of springs, and by the use of which
excellent results have been obtained in the Renovo Shops of the
Pennsylvania Railroad.
The furnace is 6 ft. 2 in. by 15 ft. over-all, and the corners are
made rigid, and further reenforced by means of angle irons,
which are held by three horizontal sets of bands or strips ex-
tending the length of the sides and ends of the furnace, and
connected at the corners. The horizontal strips hold in place
vertical plates, which are disposed at suitable points on the sides
and ends, and serve to materially strengthen the latter.
FORGE SHOP, HARDENING AND TEMPERING 61
The side walls of the furnace are further reenforced by the
use of 70-lb. steel rails, vertically located at required intervals.
Large pipes for supplying air from the blower enter the sides
of the furnace in a straight line, as this has been found more
satisfactory than when the pipes are led in on an angle.
The furnace can be supplied with air from the compressed-
air system by means of a connection entering at the same point
as the fuel oil. This arrangement is made to provide against a
possible breakdown of the blower system. The blower pipe line
is 3 in., and the oil and compressed-air lines, each % in.
The doors of the compartments, of which there are two on
each side and at opposite ends of the furnace, are raised and
lowered by pivoted levers having ball weights, and which hold
the doors in an open position when raised. Each of the com-
partments is equipped with a Thwing electrical pyrometer.
FURNACE FOR OIL-TEMPERING BATH
Fig. 40 shows a furnace designed for steel parts which
require tempering in hot oil. It consists of a brick furnace in-
closed in a steel jacket. In this is suspended an oil pan lined
with a wire basket which may be raised and lowered by chains
fastened on the end of a shaft supported by wrought-iron
brackets at either end and operated by means of a crank. The
basket is raised when the chains are wound around the shaft.
A ratchet at one end holds the basket in position while it is being
filled or emptied.
This is a very cheap device and a simple one to make, and as
it requires very little attention the upkeep is a small item.
FORGING HIGH-SPEED STEEL
Trouble with high-speed steel breaking off and showing a
coarse grain after being drawn down under the steam hammer
invariably arises either through the steel having been worked at
too low a heat or not having been properly annealed after draw-
ing down.
It is essential in working high-speed steel to get it to as high
a heat as that particular brand will stand. Work it until it is a
bright red, then reheat. Never work it below a bright red.
If the steel to be drawn down is in long lengths, take a long
heat ; but never work it the full extent of the heat. Always leave
FORGE SHOP, HARDENING AND TEMPERING 63
a margin of at least 3 in. that is not touched by the hammer
faces that is, if the heat is 12 in. long, never work more than
9 in., as the last 3 in. is not quite as hot.
If short pieces, bar ends, etc., are being drawn down, it is
possible to heat the pieces uniformly throughout. After all the
pieces have been drawn to size, place them in a casehardening
box, cover with old bone or leather that has been repeatedly
through the casehardening furnace, seal with fireclay, place in a
cold or moderately heated furnace, damper the fire and leave to
cool off.
BENDING HEAVY PIPE IN THE BLACKSMITH SHOP
A few days ago one of our shops was called on to make a half-
circle bend on the ends of four pieces of S^-in. black iron pipe
to be used for the ornamental railing of a new bridge. The
circle was rather small for a pipe of this size ; the radius allowed
being only 18-in., while the specifications called for a smooth
bend, free from kinks, and with no noticeable degree of flatten-
ing of the pipe. It was likewise desirable that there should be
no coupling near the curved portion. This necessitated using a
full 20-ft. length, which for this diameter of pipe is rather heavy
to handle. For jobs of smaller sizes of pipes and in larger
numbers, it might pay in such a case to rig up a bending jig
similar to that shown in Fig. 41, on which the pipe is bent around
a curved and grooved form A by means of a similarly grooved
roller B fitted to the diameter of the pipe being handled, and
located between the arms of an operating lever C.
However, for small quantities of job bending, the production
of such a jig would be expensive, and so heavy as to be out of
the question. For others, who may some day run into a task of
the same nature, the following description of two methods of
handling this work may be of interest.
The method illustrated requires a careful workman to get a
smooth job, and though adaptable to the largest sizes of pipe,
may require a tedious amount of work. Two stakes are required
for the necessary leverage to pull the pipe around, and although
these have in this case been illustrated as inserted in a plate D,
the latter is in itself unnecessary although desirable for keeping
the bend in a true plane.
The procedure consists of heating the pipe in a small spot at
64 AMERICAN MACHINIST SHOP NOTE BOOK
a time on the inside of the bend, as shown in the shaded portion
at E. If the heat should extend around to the outside of the
pipe, this should be chilled with water immediately before bend-
ing, the object being to keep the outside cold to prevent flat-
tening of the pipe while the pressure of the bending causes the
inside to upset, and so furnishes the shorter radius for the inside.
FIG. 41 VARIOUS METHODS OF BENDING PIPE
Only a very small portion of the pipe can be heated at a time,
and should the pressure cause the inside to start to kink at any
point, that place must be instantly chilled with water, and the
bending continued further along. On account of the constant
shifting of the heat on a very short portion at a time, the use of
an oil-torch for heating is a great advantage, as it saves carry-
ing the pipe to and from a forge, but the latter can be used if
necessary.
The method that was used on the bridge-railing job is also
FORGE SHOP, HARDENING AND TEMPERING 65
illustrated. A coupling and short length, of pipe are tem-
porarily fitted on the end at the start as shown at F. A short
heat is taken close to the coupling at G; the pipe laid over the
horn of an anvil and with a swage and sledge the bend is started ;
turning the pipe over on its side if necessary to work out any
kinks or flattening that may occur while this first bend is being
made. The added section of pipe is then removed and a quite
different method continues the work. The clamped band handle
H is now bolted on some distance back from the end ; and the
pipe itself is suspended by a block and sling so that it may be
easily raised and lowered as necessary ; and must be hung from
a support far enough above it so that it may be swung pendu-
lum fashion through a swing of three or four feet. A heavy
wood block 7 for a "butting-post" is leaned up against a con-
venient anvil or wall, as shown.
A short heat is then taken on the pipe just beyond and ad-
joining the portion that was first bent. It is then swung like
a ram against the block, and the force of the blow acting on the
tangent of the first bend causes a continuation of the bending
in this next section, while sufficient upsetting of the material
takes place at the same time so that there is no flattening down
of the outside, and the pipe holds up to its full form. This
same procedure is continued for one section following another,
and the pipe rolls up into forms as illustrated at /, where in this
case the shaded portion K indicates the place where the bending
is taking place. Care must be used that the bend does not run
out of a true plane, and if there is any tendency toward doing
so, the work must be laid on a faceplate or anvil and trued up.
In working these methods, the smith must work up to an in-
side templet, which has been made up for the radius of the inside
of the bend; using care to keep each added bend close to the
templet size to save any unnecessary bending or straightening
of the work later on when it might not be so easily performed
without reworking the whole piece.
BENDING SHORT RODS HAVING THREADED ENDS
There are many shops that have occasion to bend short rods
with threaded ends, or long rods with the bend so close to the
threaded portion that the operation must be performed after
66 AMERICAN MACHINIST SHOP NOTE BOOK
threading ; otherwise there would be no chance to get the die up
to work.
In one shop these rods, one of which is shown in Fig. 42,
were formerly bent by hand, the smith using a wooden mallet to
avoid injuring the threads, the first turn being made over the
horn of the anvil and the bend completed on a former.
As our requirements ran well into the thousands, this method
was naturally too slow, and in casting about for a more efficient
means of production, the bending fixture shown in Fig. 42 was
FIG. 42
finally evolved. A base B with its upper edge made to conform
to the shape of the finished piece carries the two levers C and D.
Firmly attached to lever C is a former E and a roller F. A jaw
H is attached to lever D, which in construction was firmly
clamped in closed position, and a pocket, half in the jaw and
half in the base, was formed by drilling and tapping to fit the
threaded end of the piece to be bent. In operation the lever C
is thrown back, striking the end of lever D and opening the
threaded pocket for the reception of the work. As lever C
moves forward jaw H grips the threads on the hot rod, but as
the pocket is fitted to them, it does not injure them. Continuing
its movement, roller F carries the work around the formed sur-
face until the final bend is accomplished by direct pressure deliv-
ered by former E. The helical spring shown exerts sufficient
pressure upon jaw H to hold the work in position during the
FORGE SHOP, HARDENING AND TEMPERING 67
bending operation. This fixture was entirely constructed in the
blacksmith shop, and in use is bolted to an anvil as in Figs. 43
and 44 which show the fixture respectively in open and closed
positions.
FIG. 43 FIG. 44
With this fixture it was found possible to reduce the working
time on a given number of pieces to one-fifth of that required by
the hand method.
RECLAMATION OF MATERIAL IN THE SHOP
Conservation of materials as well as of time can be effected
to a very appreciable degree in most manufacturing plants, by
closer attention to the subject of reclamation. The scrapping
of an article in many shops, means its consignment to the junk
pile, from whence the chances of its recovery are remote.
The demands on the producers of unfinished products are be-
coming more and more insistent, and the conditions of waste
could be reduced considerably if a systematic study were to be
made of the general run of parts that form the bulk of scrapped
material, and of their potentialities as reclaimed material.
Used bolts form a prolific sources of reclamation work, and
are easily reworked. Steel T-rails are made to withstand hard
usage, Avhile the head split from a heavy steel rail is good mate-
rial for making stubs for the business end of crowbars, set ham-
mers, and swages for the forge shop, etc. Most of them will
take a good temper and will weld readily and the reworking
necessary to bring them to the required shape materially im-
proves the steel.
68 AMERICAN MACHINIST SHOP NOTE BOOK
ANNEALING HARD SPOTS IN OXYACETYLENE
REPAIRS
These hard spots may be neutralized by the use of suitable
fluxing. I know from experience, that borax used as a flux
produces a good weld, thoroughly annealed, but when the same
identical rod was used without borax, the weld could not be
filed.
PREVENTING CRACKS IN HARDENING
The blacksmith in the small shop, whose equipment is usually
very limited, often consisting of a forge, a small open hard-coal
furnace, a barrel of water and a can of oil, is expected to, and
usually can, produce good results if proper care is taken.
Too much cannot be said in favor of slow, careful heating, or
against overheating.
My experience has taught me, however, not to take the work
from the hardening bath and leave it exposed to the air if there
is any heat left in it, because it is more liable to crack than if
left in the bath until cold. The reason for this is not hard to
find. In heating, plenty of time is taken for the work to heat
evenly clear through, thus avoiding strains caused by quick and
improper heating. Now in quenching in water, contraction is
much more rapid than was the expansion while heating, and
strains begin the moment the work touches the water. If the
piece has any considerable size and is taken from the bath before
it is cold and allowed to come to the air, expansion starts again
from the inside so rapidly that the chilled hardened surface
cracks before the strains can be relieved.
The method that I have been most successful with is to have
the hardening bath about blood warm. AYhen the work that is
being hardened is nearly cold, it is taken from the water and
instantly put into a can of oil, where it is allowed to finish cool-
ing. The heat in the body of the tool -will come to the surface
more slowly, thus relieving the strain and overcoming much of
the danger of cracking.
The temper should be drawn as soon as possible after harden-
ing ; but if this cannot be done for some hours, the work should
be left in the oil until the tempering can be done. Forming
dies and punch-press dies that are difficult to harden will seldom
FORGE SHOP, HARDENING AND TEMPERING 69
crack if treated in this way. Small tools or pieces that are very
troublesome because of peculiar shape may be hardened in a bath
composed of 1 Ib. corrosive sublimate, ^2 gal. vinegar and % bbl.
rainwater at a much lower heat than is required for clear water,
the temper to be drawn in the usual way. This bath should be
warmed the same as the water, and the work hardened in it
should be also put in the oil. This solution works well on drill
bushings, taps and dies, small punches and the like.
For high-speed steel in such a shop as the one I have just
mentioned, and where a small hard-coal furnace is located, ex-
cellent results may be obtained in the following manner : Place
on the fire a graphite crucible large enough to admit the work
to be heated without touching the -crucible. Build up brick as
high as the top of the crucible ; fill that with lead, and the space
between the crucible and the brick with coal. When the lead
begins to boil, skim it and cover its surface with fine charcoal.
Now put on blast enough to bring the heat up to the degree
wanted. If the lead is kept well covered with charcoal, it will
not burn away. Preheat the work on the fire before it is put
into the lead. A uniform heat is thus obtained. Some small
particles of lead will stick to the work, but will scrape off easily
after the tools are cold. Taps, dies, reamers, milling cutters
and, in fact, all fine tools may be heated in this way without in-
juring their cutting edges.
The writer has used this method for a number of years and
has had very few complaints. The tools thus hardened give as
good satisfaction as those which were heated in an electric fur-
nace.
TEMPERING THIN SNAP GAGES
On a recent large order of snap and angle gages for various
gun and gun-carriage parts the company by whom I am em-
ployed experienced difficulty in getting the gages through the
hardening without warping.
As the number to be made ran into the hundreds, the matter
was given much thought, and several kinds of steel was experi-
mented with. A few gages of mild steel were made up and sent
out to a hardening concern to be carbonized, but they came back
so badly warped that most of them broke in the straightening
The company then decided to do the tempering itself and use
70 AMERICAN MACHINIST SHOP NOTE BOOK
Firth sterling special tool steel for all the gages, as these were
so light that the cost of material was unimportant when com-
pared with the results gained.
The method used in tempering the gages, some of which were
14 in. long and %e in. thick, while it may be "old stuff" to some,
still worked beautifully and may serve to help others engaged on
similar work. We made a shallow pan about 3 in. deep of
heavy galvanized iron and placed in this an ordinary surface
plate, the pan being considerably larger than the plate, which
was, of course, selected to be a little longer and wider than the
largest gage. We then filled the pan with good fish oil to about
% in. above the surface of the plate.
The gages had been first roughed out, annealed and then
worked to size. They were heated in a cyanide bath to a me-
dium-cherry red and the hardener simply laid them on the sur-
face of the plate in the oil while his assistant placed over them
a plane-surfaced weight fitted with handles so as to be easily
handled. When I tell you that some of the gages 14. in. long
cleaned up on the surface grinder with the removal of only
0.003 in. stock you will realize how simple and effective is this
method.
Slitting saws or any other tools having a uniform thin sec-
tion can be successfully hardened, and this cheap but effective
rig will be an appreciable addition to any hardening or toolroom.
BRAZING A BROKEN PAIR OF SCISSORS
Some years ago when I was an apprentice in a small, old-
fashioned shop in Aberdeen, Scotland, a novel repair job came
under my notice, namely, brazing a pair of scissors which were
broken in one of the legs just back of the pivot hole, as indicated
in Fig. 45. As the break happened to be a clean one the
following method was used to join the two pieces: A small
dovetail was cut at each end of the broken parts, a piece was
fitted to the dovetails and lightly tapped in with a small hammer
to keep the parts in position while the brazing was done. To
keep the temper from being drawn from the cutting edge during
the brazing operation I was sent out to a near-by cafe for a
potato into which the fitter stuck the scissor 's leg, the potato
practically covering the cutting part thereof, and just leaving
FORGE SHOP, HARDENING AND TEMPERING 71
the part which was to be brazed sufficiently clear to allow the
flame to be used. The operation was entirely successful and
the scissors practically as sound as when new. The potato being
moist served to keep the scissors' leg cool .during the brazing.
Break HerQ
FIG. 45 POTATO USED TO KEEP BLADE COOL WHILE BRAZING
Needless to say I have never forgotten the somewhat unusual
method and have since employed the idea for similar jobs.
SHRINKING ON A LARGE SLEEVE
I recently had to shrink a large bush on a long shaft. The
job was an odd one in this shop, so I got all kinds of valuable
information regarding it while I was preparing to do the work.
The foreman said he thought it best to leave the bore in the
FIG. 46 How THE WORK WAS HELD
bush about VG in. smaller. I settled this dispute by getting
out my " American Machinist Handbook" and, turning to page
231, found that about 0.005 in. was sufficient for a 9-in. bush.
If the bush of cast steel were made %2 in. smaller than the
72 AMERICAN MACHINIST SHOP NOTE BOOK
shaft, it no doubt would be so strained beyond its elastic limit
that its grip would be greatly reduced.
A bush of this size and weight could be nicely slipped over a
shaft when in a vertical position, but the shaft being too long
we proceeded as shown. The shaft was supported upon two
timbers and the bush supported a % x 3-in. bent iron securely
fastened to the floor, after the bush was lined up. We then
heated it just a little hotter than mother 's flat iron and shoved it
home.
Do not attempt to put a bush of this size and weight over a
shaft without some means of guiding it on parallel with the
shaft, for it is almost sure to catch.
SECTION IV
DRILLING MACHINE
POSITIVELY LOCATED DRILL JIG
WITH this contrivance a piece with any number of holes may
be jigged and drilled without any possibility of the jig rotat-
ing and becoming dangerous to the operator. Pig. 47 shows
the arrangement.
FIG. 47 POSITIVELY LOCATED DRILL JIG
A is the jig proper ; B is a piece slotted as shown. It may be
part of the jig or a piece attached to it in any manner best
adapted to the general shape of the jig, so that it lies flat with
the jig on the drill table. At C is a bolt threaded within the
thickness of the piece B from the head of the bolt and having a
diameter equal to the width of the slot, so that the piece can
slide in any direction around the bolt.
73
74 AMERICAN MACHINIST SHOP NOTE BOOK
The bolt is screwed into a hole tapped at one end of the drill
table D. Then the jig can be slid to bring any hole into position
directly beneath the drill, and the bolt will act as a stop and pre-
vent the jig from rotating and working loose while drilling.
The jig can easily be taken from the table for inserting the
work and may be dipped in a pail of washing soda for cleaning.
The jig is easily positioned and easily handled.
AN ADJUSTABLE ANGLE IRON
After designing a drill jig for a piece of work that had five
angular holes, besides a few straight ones, my next proposition
was to design angle irons that would give the required angles.
Formerly all drill jigs used for drilling holes in a piece of
work on an angle had a separate angle iron for each hole. My
FIG. 48 ADJUSTABLE DRILL JIG
idea was to do away with all but one, thus cutting down ex-
pense.
Fig. 48 shows the main base made of cast iron, which holds
the hardened and ground steel bushings that are inserted to give
the different angles required.
The top plate, upon which the drill jig is set, swings on the
lower pin and rests on the long locating pin with the knurled
handle. The plate also has two small hardened steel plates
screwed on, as shown. These take the wear on the hardened
and ground steel locating pin.
DRILLING MACHINE
75
It is well to stamp or in some way mark opposite each hole
the angle it is for.
This angle iron proved very satisfactory, and the design was
followed out in all others that were made. We found that the
adjustable type not only cut down tool expense and the bother
of having five angle irons around the drill press, but also con-
siderably increased production.
MAKING ANGLE-FACED WASHERS
A large number of taper washers like the one shown in Fig. 49
were being called for made of duralumin. The first order was
for 10,000 and the way we got at the job may be of interest.
The blanks were punched accurately to size from sheets, after
FIG. 49 FIXTURE FOB MAKING TAPERED WASHERS
which they were inserted in the fixture shown at the left for
drilling the hole. This fixture was built up principally from
scrap and is not difficult to make. The holder A had previously
done duty as the bridge piece of a stop valve, and the baseplate
B is made from mild-steel plate. The inclined-plane piece C
was forged and pinned on as was bracket D. A number of
washers are shown in position for drilling in recess E while re-
cess F is ready for loading. The washers are clamped by the
76 AMERICAN MACHINIST SHOP NOTE BOOK
threaded guide bushing, operated by means of the handle G,
onto the bolster H.
A small sensitive drilling machine is used, and when the
washers are in the position the power feed is put on and the
operator then loads recess F. An automatic trip is used, and
when drilling is completed handle G is pushed back and holder
A turned half round, bringing the next dozen washers in posi-
tion. When turning, bolster H travels up C, ejecting the fin-
ished washers, the operator catching these with his left hand.
With this fixture practically continuous drilling is obtained and
very little skill is required; in fact the most difficult part at
first was to have the hand in position as the washers were
ejected, otherwise some fell on the table and the remainder
dropped back into the recess when the bolster dropped.
After the drilling the washers are placed in the chuck shown
at the right, which is operated by handle 7. Beneath the washer
a steel washer J is placed as a packing piece. It raises the
work slightly above the chuck and by means of the counter-
bore K one side of the washer is faced, the depth being regu-
lated by means of the pilot coming in contact with 'stop L.
An ejector M is arranged in conjunction with handle / to lift
the work when the handle is pushed down and the chuck re-
leased. For facing the opposite side of the washer the same
fixture is used, with the substitution of a steel packing piece of
exactly the same angle as a finished washer for the packing
piece J. Although close limits are required for thickness and
angle and smooth faces these methods proved very satisfactory.
AN ADJUSTABLE JIG FOR DRILLING ROUND
PIECES
A handy tool for service around a sensitive drilling machine
is shown in Fig. 50. Small Vs are located on both the fixed and
the movable jaws, and T-slots are provided at each end for bolt-
ing in position any small work that may require holding in an
upright position.
Brackets are provided to clamp in any position in the slots,
and carry the flat adjustable bar which is designed to hold
drill bushings of various inside diameters as well as a clamping
screw to hold any work that may be placed in the adjustable V
DRILLING MACHINE 77
formed by the conjunction of the interlocking jaws. The bar
is graduated for convenience in bringing the drill bushing to
center in whatever position the jaw may be.
FIG. 50 AN ADJUSTABLE DRILL JIG
CUTTING HOLES IN GLASS
It is sometimes necessary on experimental work to drill holes
in glass. A job of this kind came to us a short time ago, the
work being to drill a %-in. hole through the bottoms of six can-
ning jars made of ordinary bottle glass,
78 AMERICAN MACHINIST SHOP NOTE BOOK
If the glass is uniform in thickness and of a high grade, a
hole can be drilled with a diamond drill, but where the thick-
ness is not uniform and the glass is poor this cannot be done sat-
isfactorily. It was found that where the bottom of the jar
joined the sides the thickness of glass varied from % to a /4 in.
The result was that when we started to drill, the strain was
Cutting Mixture
Turpentine and -
Carborundum Dust
COPPER
./'TUBE
FIG. 51 DRILLING GLASS JABS
taken by the thin section of the bottom, which would crack and
fall out.
After using different speeds and varying the cutting com-
pounds the idea of drilling was given up and the following plan
was hit upon, which worked successfully. We held a %-in.
copper tube in the chuck of a drilling machine and used turpen-
DRILLING MACHINE 79
tine and carborundum dust for a cutting compound. The glass
jar was placed on the table, inverted and firmly clamped. The
operator put just enough pressure on the lever to keep the tool
grinding and soon the hole was through.
We lost a few by this method, but it was because the bottoms
were of varying thicknesses, also blowholes were found which
tended to weaken the glass.
When selecting glass vessels to be drilled, select those that
are of even thickness, and breakage will be practically elimi-
nated. Fig. 51 is self-explanatory and shows the complete
set-up.
Though I have not tried it I believe if the jar were set on a
piece of felt and held by the hand the result would be as good
as that obtained by clamping the jar.
A JIG FOR DRILLING STEEL DISKS
Fig. 52 shows a jig for centrally locating, drilling and
reaming tool-steel disks. Besides being held between the jaws
A and B the disk is held down by the bushing C that locates the
hole. This bushing screws into the leaf of the jig and bears
FIG. 52 JIG FOB DRILLING STEEL DISKS
upon the disk, thus preventing it from buckling, while the
combination drill and reamer does its work.
The jaws are provided with fine teeth (about 50 to the inch)
to hold the disk firmly and prevent it from turning. A is the
sliding jaw, and it is actuated by the cam lever Z>. The yoke E
80 AMERICAN MACHINIST SHOP NOTE BOOK
is not absolutely necessary, but it is an aid to rapid production.
The sliding jaw A is guided in its movement by the two
pieces F. The leaf G turns upon a stud and is clamped in place
by the thumbscrew H.
SMALL MOTOR-DRIVEN DRILLING MACHINE
USED FOR TAPPING
I have been using a bench drilling machine for some time for
the purpose of tapping small motor parts, such as rotors, jour-
nal boxes, frames, etc., driving by means of a d.-c. motor of Vz
hp. running 950 r.p.m. The reversal of the tap is accomplished
by reversing the motor with a small switch operated by a
treadle, a spring closing the circuit and running the motor
forward, while pressure on the treadle reverses the motor and
allows the tap to back out.
The field circuit in the motor is left closed to prevent spark-
ing when the armature is reversed. To reduce tap breakage to
the minimum the amount of torque is controlled by loosening
or tightening the belt.
This idea, so far as I know, is original and I hope it may be
of value to others.
INCREASING THE SIZE OF A SHELL REAMER
In the small job shop we get some strange work to do and have
to do the best we can with the available equipment. In a
hurry-up repair job it was necessary to ream four 3.005 in. -diam-
eter holes in a gray-iron casting abort 8 in. thick. These could
be a plus-or-minus limit of 0.001 in. in diameter, but the holes
must be round and straight. The casting, because of its size
and shape, could not be handled in any lathe or boring mill we
had, nor could the holes be bored with a bar without a lot of
extra work, so I decided to drill and ream them. As we did not
have an expanding reamer a mild-steel taper mandrel was
fitted to a worn-out 3-in.-shell reamer, the mandrel being turned
about 3 in. further than it would go into the reamer. A split
bushing was then made to fill up the chamber in the center of
reamer so that with this split bushing in place the hole in tki
reamer was a true taper hole.
DRILLING MACHINE 81
The bushing was then sprung into the reamer, and both being
brought to a good red heat the taper mandrel was driven in as
quickly as possible until the reamer was stretched as much as
was thought to be necessary. The reamer was then tempered, a
new bar made for it, and it was ground to fit a collar that had
been bored to 3.005 in. A test collar was then reamed, which
proved to be right size. I did not grind the hole in the reamer
nor the face of the flutes as would have been done if there had
been sufficient time. By the time the reamer was ready the
first hole in the casting had been drilled and reamed with a 3-in.
standard reamer. The oversize reamer was then put through
and the other holes machined in like manner. On installing
this casting (in a hydraulic press) the job was found to be per-
fectly satisfactory and it was done in much less time than was
anticipated.
ECONOMICAL HIGH-SPEED STEEL COUNTERBORE
In view of the present high price and the difficulty of obtain-
ing high-speed steel, it behooves both designer and shop man to
exercise their brains in the interest of conservation.
The accompanying sketch shows a method of making high-
speed steel counterbores with a minimum of this expensive
material.
D
:_nj ran /TTN
L - e fi m w:
D A
FIG. 53 ECONOMICAL HIGH-SPEED COUNTERBORE
The counterbore A is made double-ended with a center hole
of suitable size passing clear through, and is tapped at the side,
midway of its length, for a headless setscrew. The driver B is
made of unhardened tool steel with same sized center hole as the
counterbore; it is tapped on the side for the setscrew, and has
teeth cut the same as in the counterbore, in order that the two
parts will interlock when they are placed together. The pilot
passes through the counterbore and is fastened by the setscrew
in the driver. The setscrew in the counterbore is to prevent the
82 AMERICAN MACHINIST SHOP NOTE BOOK
latter slipping off when pilots of the same size, or smaller, than
the center hole are used.
A RADIUS-CUTTING BORING BAR
Having a steel casting to machine in a half circle with a
4-in. radius, and our lathe being too small to swing the casting,
it may interest some of your readers to know how the work was
done on a 21-m. upright drilling machine.
Fig. 54 shows the device assembled ready for work, also some
of the details. Fig. 55 shows the work which has an opening
f F
FIGS. 54 AND 55 THE BAR AND THE WORK
through it which permits the passage of the pilot of the boring
bar. The boring bar A, Fig. 54, is similar to the one used
in many shops for counterboring, and was made with a No. 2
Morse taper at its upper end, while the lower end was
centered to run on a center secured to the base plate of the
drilling machine, and running through the table of the latter.
In this way the bar was kept from springing while taking a
34-in. cut.
A %-in. hole was drilled through the bar, and it was then
planed off on each side to afford a bearing for the stud B, the
DRILLING MACHINE
83
shank of which was threaded and extended through the bar, and
held in place by nuts. This stud B was provided with a %-in.
hole for the passage of the feed screw C, having a coupling
yoke at its lower end, and receiving a feed nut D, which was
made so that it would come up to the stud just tight enough to
turn. The nut D was made with a ^-in., 20-thread hole tapped
through, and was fitted on the feed screw, and extended through
the opening in the stud B, where a collar E was pinned, so that
the feed nut could turn freely and yet be securely fastened.
A }6-in. tapped hole was provided in the boring bar to receive
a stud F on which the cutting bar G was pivoted. One end of
cutting bar was journaled in the yoke of the feed screw. The
cutting bar was of %-in. square key stock, bent on one end to
bring the cutting tool in line with the center of the bar, as
shown at H.
Care should be taken to have the length of the cutting bar G
from its center, where it is mounted on the stud F to the point
of its connection with the feed screw, equal to the distance from
YtoZ.
The action of the device is simple. When the drill is started
the cutting tool is fed to the work by turning the feed nut D.
FIXTURE FOR DRILLING SMALL HOLES
In the production of percussion pellets for time fuses, the
tooling on the automatic screw machines which produced these
parts, was such that it was impossible to counterbore the small
hole in the end of the pellet. This operation was therefore done
Percussion Pelfet
FIG. 56 FIXTURE FOB DRILLING SMALL HOLES
84 AMERICAN MACHINIST SHOP NOTE BOOK
on a drilling machine with the fixture illustrated in Fig. 56.
The base of the fixture was made as thin as possible so that the
operator could rest arms and hands on the drilling-machine
platen in order to operate the fixture with the least amount of
effort. The handles were gripped in the left hand, and a
definite number of pellets found their way through an orifice in
an elevated box, down a chute to the drilling-machine platen.
r/^ : : " " ~ ~ j '*-''*?$?&&"**'
FIG. 57 BORING ENGINE GUIDES
The pellets were placed on their correct ends for drilling, and
fed along one after the other. An undrilled pellet pushes one
that is drilled out of the fixture down another chute and into a
box. This feeding operation was done without interfering with
the drilling operation, because the drill spindle was operated
with a 5-ft. treadle. The spindle speed was 8000 r.p.m., and
the production in 9 hours was 15,000 pieces. The recesses cut
in the clamps A, center the pellet while the pilot on the counter-
DRILLING MACHINE
85
bore, insures concentricity. The compression spring B for
holding the clamps open was discarded, as the operator found it
unnecessary for this class of work. For some kinds of work,
however, it would be an advantage.
BORING ENGINE GUIDES
Fig. 57 shows how a small machine shop tackled the problem
of boring the guides of a small engine. The only machine avail-
able for the job was an upright drilling machine. There was no
possibility of supporting the bar at both ends, as the hole next
to the table was too small. A guide was rigged up as shown,
clamped to the sides of the drilling machine and the engine cast-
ing located on parallels. A boring head with the roughing tools
in advance of the finishing tools, and a roller steady immediately
behind them, made a good speed job.
DRILL JIG FOR Y CONNECTIONS
In the illustration is shown a simple and very effective drill
jig for small Y-shaped castings. These castings, which are made
FIG. 58 DRILL JIG FOR Y CONNECTIONS
of brass, are used in considerable quantities as soldered unions
in oil pipes, gas lines, etc. The holes are drilled for }4-in.
tubing.
86 AMERICAN MACHINIST SHOP NOTE BOOK
The body of the jig is of steel, about 114 in. thick, originally
a round piece about 4 in. in diameter. The central hole is bored,
and the piece is given six flats, as it is drilled from three direc-
tions.
The knurled screw bushing in the top is bell mouthed to center
the casting, and forces it down into the double V-block milled
from a round pin. A side view of the V-block is given; it has
90-deg. notches milled in 45 deg. each way from the center line.
The thread 011 the screw bushing is cut eight to the inch and
% in. in diameter. Two turns of this screw release the casting
completely. As may be imagined, it is quite rapid in operation,
the rate being about 175 to 200 pieces per hour per operator.
REDUCTION HEAD FOR DRILLING MACHINE
Fig. 59 shows a specially designed gear reduction head to be
used in connection with the drilling-machine spindle, where low
FIG. 50 GKARKD REDUCTION HEAD
DRILLING MACHINE 87
speeds are not available. This head may be designed to give any
gear ratio required, according to the safety strength limit of the
drilling spindle and the nature of the work being done. The
head is able to clean up castings that have too large a projecting
portion to be conveniently swung in a lathe, and as an auxiliary
to the milling machine it will prove very handy.
At A is the driveshaft, fitted the drilling-machine spindle.
The latter on its lower end, is cut to form a pinion, engaging in
the two idler gears B. These idler gears are compound, having
been stepped down, and in turn they engage in the reduction
shaft C. The idler gears, being mounted in a floating case Z>,
have a tendency to turn backward or creep around the reduc-
tion shaft when load is applied ; but this action is prevented by
applying to the case a rod E, which is allowed to rest on the up-
right of the drilling machine. There is a bearing of the extreme
end of the shaft A in the shaft C ; this gives rigidity and pre-
vents wabble, while the ball races F take up all the end thrust.
A great variety of work can be done with this head, espe-
cially in experimental shops and jobbing shops. It will be
found to be a very accurate and handy tool for reaming and in
using fly cutters.
DRILLING MACHINE MADE INTO A PRESS
Having to pierce a great many holes varying from Vs to WQ in.
in diameter in strip brass from No. 20 to No. 14 gage and in
sheet steel No. 24 gage, I considered drilling too long an opera-
tion. Therefore, I constructed the attachment in Fig. 60, mak-
ing of the drilling machine a very serviceable and efficient punch
press. I removed the pinion that engages the rack on the quill
and bushed the hole, allowing passage for the H-in. bolt A.
I then bent the piece of 1% x *H6-in. flat iron B, forming the
handle and half the toggle. Two straight pieces C of the same
stock completed the toggle. Another piece of the same flat was
bent into a U and drilled for a ^-in. bolt at D, so that it just
rested on the top of the frame when the flat was up against the
under side. A light tie-rod E, of %-in. round iron threaded on
the ends for nuts, held a section of 2-in. angle iron, thus support-
ing and taking the pressure from the table. The spindle was
raised to its limit and locked by the take-up screws F. To elim-
88 AMERICAN MACHINIST SHOP NOTE BOOK
inate any further motion, a ^-in. stud was passed through the
tang slot and screwed into a tapped hole in the head H, the tight-
ening screws of which were drawn up just so the head could slide
on its ways /.
FIG. 60 DRILLING MACHINE USED AS A PUNCH PBESS
With this arrangement I secured a %-in. stroke and pierced
Tie-in, holes in No. 20 gage brass without the slightest difficulty.
SPECIAL COUNTERSINKING TOOL
The device shown in Fig. 61 has been used successfully to
countersink a hole where it breaks through into a slot, as desig-
nated at C. According to the dimensions given, of course, the
tool is adaptable only to this particular job. However, it may
suggest a principle that could be applied to similar conditions.
A is a piece of 9ie-in. drill rod slotted to take the pivoted cutter
B, which is kept in the position indicated at B by centrifugal
force. On entering the hole in C, the extending end is shoved
DRILLING MACHINE
89
back, which brings the lower end out into the slot in position to
cut. A hardened collar serves as a stop to regulate the cut and
prevents the cutter from digging into the work.
FIG. 61 SPECIAL COUNTERSINKING TOOL
RECESSING TOOL
The machining of a recess in a small cylinder to very accurate
limits has caused considerable trouble, so I have designed for
the operation the tool shown in Fig. 62. This tool can be
applied to any vertical drilling-machine chuck or to any auto-
matic lathe.
The guiding bushing E enters the bore of the cylinder to be
recessed, until the end of the cylinder comes in contact with the
stop ring D, which rides on the balls M. Further movement of
the tool causes the driving shaft A to press against the spring B,
and the tapered end of the driving shaft then engages in a
conical hole in the sliding toolholder (7, causing the tool to move
radially and cut the recess.
The adjusting nut F limits the movement of the driving shaft,
thus controlling the depth of the recess. The spring H returns
the sliding toolholder to its original position, so that the tool
is in the position shown in the sectional view. When thus lo-
cated the drilling spindle is raised and the tool withdrawn from
the hole without touching it.
90 AMERICAN MACHINIST SHOP NOTE BOOK
This Dimension
must be very accurate
Retaining
Ring
'ecess/ngToo/
Cylinder-
FIG. 62 RECESSING TOOL FOB ACCURATE WORK
DRILL-CENTERING DEVICE FOR V-BLOCKS
To make a quick and accurate job of drilling holes in small
round stock such as may be required in the general work of the
toolroom is not always an easy task. No matter how carefully
the job may be laid off or how warily the drill may be coaxed
to straddle the curved surface, the resulting hole is never a safe
bet. The device illustrated in Fig. 63 stops the uncertainty
and saves much time besides. In reality, it is an attachment
for a V-block about the size of the ordinary tool-makers 7 block
sold by the Starrett and the Brown & Sharpe companies. The
size described here was designed for the kit of the workman at
the bench, but the field of usefulness could easily be enlarged.
DRILLING MACHINE
91
Made up on a little larger scale, it would be handy as a general
toolroom fixture.
The capacity is for stock from V& to 1J4 in., and for holes from
We to */4 in. The outside diameter of the bushings is % in.
They are a slip fit in the holder and are prevented from turning
by a small set-screw tightened against a small flat, ground on
the side. The holder is a close sliding fit between the ways and
is clamped at any height by the thumb-screw at the back.
After the piece to be drilled is clamped down in the V, a bush-
FIG. 63 V-BLOCK WITH BUSHING HOLDER
ing of the size desired is placed in the holder, which is then ad-
justed on the ways so as to bring the lower end of the bushing
close to the work, thus dispensing with laying off or using care
in centering. In slotting small cutter bars, for example, it is
required that the bulk of stock be removed by drilling to leave
the slots in shape for finishing with an end mill or the more
primitive way filing.
First, mark the center of the radius at one end of the slot and
clamp the piece in position. Then with the V-block in place on
the drill table or other flat plate, fasten a lathe dog or similar
device on the free end of the work being drilled, so that the
tail rests against the plate. This will keep the row of holes in
line, and they can be so far overlapped that very little stock will
be left, thus making a quick job in the finishing.
92 AMERICAN MACHINIST SHOP NOTE BOOK
In connection with the slot drilling, it will be well to mention
the sliding center point, which is placed at the bottom of the V,
in the center line of the drill bushing. This center, having an
angle somewhat sharper than a drill, is a close sliding fit so that
it may be easily removed after the work is located and clamped
in position. ' If a hole must be accurate in distance or angle
with other parts, it can be marked and punched and this center
point be brought up in the punch mark to locate it. The main
use for the centering point, however, is to locate holes diametric-
ally opposite in tubing or other work, as shown in the cross-
section sketch. In drilling small holes through work of com-
paratively large diameter where the stock is tough, it is better
to drill halfway through, then turn the piece halfway over,
locate it and finish from the opposite side.
FIG. 64 SWEEP TOOL FACING THE BEVEL GEAB
DRILLING MACHINE
93
MACHINING BEVEL PINIONS
About three years ago, while with a large auto concern in
Detroit, I worked out a tool set-up for machining the main-
bevel drive pinion shown in Figs. 64 and 65.
The first operation to finish the taper hole and face back
is done in a screw machine or automatic turret lathe. Opera-
tion 2 keyseating is done on any keyseater.
Operation 3 finishing the front face and angle is done in
a high-speed drill press by the tool shown in Fig. 64. The hold-
ing fixture consists of a hardened taper pin in a steel block with
a fixed key. The gear is placed on the taper pin and swept to
form and size by the high-speed facing-form tool in the drill-
press spindle, which pilots on the taper pin in the table fixture.
The end of the shank extends into the pilot hole in the form-fac-
o
FIG. 65 THE LATHE SET UP FOE BACK AND FRONT
ing tool, and the form tool is threaded and secured by a locknut
on the spindle. This allows an adjustment for grinding and
also for maintaining the correct thickness of the blank, as the
tool is forced by hand until the reduced end of the shank bears
on the pilot of the taper pin, always assuring a close dimension.
Operation 4 is done in a lathe with the equipment sketched in
Fig. 65. The headstock spindle is fitted with a ball center ; the
tailstock spindle has an arm with the center set at an angle and
off center to correspond with the face angle of the pinion. The
lathe is equipped with two toolposts, one for finishing the back
angle and one for turning the outside diameter,
94 AMERICAN MACHINIST SHOP NOTE BOOK
After the size is secured, the cross-slide is locked and not
moved. When the cut is finished, the ball-center arbor with the
gear is removed, the carriage run back, another arbor with gear
put in, the back angle finished first by forcing the carriage back
to a stop, then the outside cut started. While this is going
across, the operator removes the finished gear from the second
arbor and places an unfinished blank on it ; consequently, a con-
tinuous operation is secured.
On operation 3 facing the end of the blank it is possible to
get 200 per hour from nickel alloy blanks about 3V4 in. in diam-
eter.
On operation 4 facing the back angle and turning outside
diameter the rate was 25 per hour on the same-sized blank.
SIMPLE DRILLING JIG FOR USE ON A YOKE
CASTING
The jig shown in Fig. 66 for drilling two %6-in. holes through
the yoke casting D is inexpensive and can be quickly made.
IV "
D
j i
Work
Clamp Ring
V-B!ock
FIG. 66 DRILL JIG FOE A YOKE
DRILLING MACHINE 95
One end of the jig is shown in the perspective ; the opposite end
is rigged up the same.
The V-block A and the two clamping rings B were made of
scrap. The two pilot bushings C have the same diameter as the
bearings to be drilled. The bushings C are clamped in the V-
block A by means of the clamping ring B and the setscrews E.
Two lengths of the yoke castings D can be drilled on this jig,
with overall dimensions of 10 and S l5 /w in. respectively. The jig
can be changed instantly for either job.
The drilling is done in a drilling machine, the jig resting on a
center in the table. The top hole is drilled and the jig reversed
for the other hole.
SECTION V
ENGINE LATHE
THREADING DIAL
ALTHOUGH the lathe is generally regarded as the simplest of
all machine tools, it is doubtful if any mechanical feature is as
little understood by the average mechanic as the lathe threading
dial. If used according to the directions, it generally produces
the desired result ; but how and why is to most machinists a hid-
den mystery.
In order to explain fully the mechanism, certain things must
be emphasized: First, most lathes have 6-pitch lead screws;
next, the threading dial is divided into ten parts by five long
and five short lines. By counting the number of teeth on the
worm gear that meshes with the lead screw at the bottom of the
dial shaft, it will be found that there are 38. Therefore, 30
turns of the lead screw will cause one revolution of the dial ; or
six turns of the 6-pitch lead screw, which is 1-in. travel, will
move the dial one-fifth revolution, or from one long line to the
next long line. The space between any two long lines or any
two short lines on the dial represents 1-in. travel of the lead
screw. The space between a long and a short line would conse-
quently mean ^-in. travel of the lead screw. Therefore, when
chasing threads which are an even number per inch, as eight,
for example, the carriage can be moved from one line to the
next, or ^ in., which equals four threads of the eight on the
work, thus allowing the threading tool to enter the work thread
properly. Hence, the rule on the dial, "When chasing even
threads, engage nut at any line."
For chasing odd threads, such as 13, it will be plainly seen
that by moving the carriage one division of the dial, or % in.,
the threading tool will be moved % in. along the work, or 6^
threads. If the nut is engaged at this point, the threading tool
will enter the work at 6^ threads, thus splitting the thread;
96
ENGINE LATHE 97
but by moving the carriage from a short line to a short line, the
carriage is moved 1 in., or 13 threads, which allows the thread-
ing tool to enter the work thread properly. Hence, the rule on
the dial, "When chasing odd threads, engage nut on short lines
only," or on the long lines only, if that threading was started
on a long line.
By observing the dial again, it will be seen that the long lines
are numbered 1, 2, 3, 4 and 0. The following will explain why :
Suppose the pitch of the work thread is 4 1 /. By moving the
carriage one mark, or Vz in., we get 2 l /i threads on the work.
This will not allow the tool to drop into the work thread. By
moving the carriage from a long line to a long line, or 1 in., we
get 4% threads on the work, which still will not allow the tool
to engage the work thread. But by moving the carriage two
long lines, or 2 in., we get nine threads on the work, which
allows the threading tool to engage the work thread properly.
Hence, the following rule, which I have never yet seen on a
machine, but which is generally to be found under the hat of a
good mechanic: "When chasing threads of a pitch involving
one-half of the thread in each inch, as 4%, engage the feed nut at
line 1 for the first cut ; for the second cut, skip one long line and
engage on line 3 ; for the third cut, engage at 5, and so on until
the thread is finished.
BREAKAGE OF ROUGHING TOOLS
Considerable trouble had been experienced in having high-
speed roughing tools break in two in the middle directly under
the screw of the toolpost. Sometimes they would even break
when a very light cut was being taken.
On first thought, I attributed the breakage to cracks caused by
a flaw in the steel or improper heat treatment, but upon making
a very careful examination of a number of these fractures I
could discern no trace of a flaw or crack in the steel.
I reduced this trouble to a minimum by placing under each
tool, after it was placed in the toolpost, a piece of ^-in. flat iron
the width of the tool and about 6 in. long. This, acting as a
cushion, tended to overcome the unevenness of the bottom of the
tool caused by redressing and treating.
98 AMERICAN MACHINIST SHOP NOTE BOOK
SPHERICAL TURNING WORK
At the top in Fig. 67 is shown a low-pressure air compresser
piston for which it was necessary to devise some rapid as well
as accurate means of turning the spherical surface A. The
work, illustrated in dotted lines, is placed on the cast-iron cen-
tering block F, which has a hardened steel-center bushing G,
and fits snugly to the 6% in. inside diameter of the piston. On
the other end is clamped a lathe dog E, driven by the faceplate,
and the work is ready to put on the lathe.
I V I.
Work
Turning' Fixture
FIG. 67 SPHERICAL TURNING
B is a machinery steel plate about 3 in. wide and 1H in. thick,
fastened securely to the bed of the lathe with 1-in. capscrews.
The swivel link C is l 1 /^ in. wide by % in. thick made from ma-
chinery steel and case-hardened. This link is fastened to the
strip B, and to the cross slide by means of two casehardened
machinery steel studs Z>, allowing the link to swivel as the tool
is fed in.
The tool is held in the toolholder on the cross slide, and the
carriage is loose to allow free movement along the ways. As
the cross-slide is fed in by the handwheel H, the link forces the
carriage toward the head end and causes the tool to travel on
the required radius. The center distance between the studs in
the link C is 5 in., the same as the radius on the finished piston
and the center of the stud D, and is located directly under the
center of the radius on the piston. This rigging is inexpensive
and efficient, giving highly satisfactory results.
ENGINE LATHE
99
A SAFETY LATHE DOG
Fig. 68 shows a means of making the ordinary lathe dog a
safety one. A piece of cold-rolled steel A is bent in circular
form with its ends flattened. These flattened ends are pro-
FIG. 68 SAFETY LATHE DOG
vided with holes to receive screws for attachment to the lathe
dog B as shown. This steel piece is of such size that the clamp-
ing screw C is permitted to clear the opening in the dog which
receives the stock.
CHUCK WRENCH REPAIRS
We had considerable breakage and wear on chuck wrenches
and decided upon the following procedure : An apprentice was
FIG. 69 CHUCK WRENCH END
given the job of turning up a number of bushings as shown in
Fig. 69. The blacksmith heated them and drove a square drift
through the small end. The hole at the end B was made a size
suitable for a shrink fit on the shank of the old wrench.
100 AMERICAN MACHINIST SHOP NOTE BOOK
EMERGENCY FOLLOW REST
A few days ago, while passing through the shop, I noticed an
"old-timer" turning a small long shaft on a large lathe, an
emergency job. His steadyrest jaws could not reach so small
a shaft, and the shaft was too long to be turned without a rest
of some description. He took a straight-tailed dog, put it on
FIG. 70 EMEKGENCY FOLLOW REST
over the tool post in the manner shown in Fig. 70 and adjusted
it to bear upon the shaft. He had a follow rest that, so far as
doing the work effectively, could not well be beaten. The job
was turned smooth, without chatter and in record time.
When I felt obliged to commend him, he replied that he had
used the same method years before.
FACING THE BOSS ON A LARGE CASTING
Some time ago some castings weighing about two tons each
were delivered to our shop for the purpose of having a boss that
was on one end of the castings faced off. There were no plan-
ing machines in the shop large enough to do the work nor had
we any convenient means of handling such heavy pieces, there-
fore it was necessary not only to devise a way of removing the
stock, but to do it in such a manner as to involve the least
amount of handling, both of which requirements were met as
here described.
ENGINE LATHE'
The set-up is shown in Fig. 71. Two 18-in. I-beams were
bolted to the floor plate of a radial drilling machine, parallel
and a convenient distance apart, to which at one end was
bolted the headstock of a lathe in position to bring the cone into
alignment with the cone of the radial, the drive being by belt
from the latter.
On the faceplate of the lathe was bolted a facing attachment.
FIG. 71 FACING A Boss ON A LARGE CASTING
The castings were put in place with a couple of chain blocks,
bars, roller, etc., and secured in position by long T-head bolts
running down to the slots in the floor plate.
The time required to face each casting was about 45 min., and
the operation did not interfere with the continuous use of the
drilling machine.
ANGLES FOR SQUARE-THREADING TOOLS
When cutting square threads some workmen are inclined to
grind the tool as shown at A, Fig. 72, and while favorable re-
102 AMERICAN MACHINIST SHOP NOTE BOOK
suits are sometimes obtained, the sketch B will enable the me-
chanic more readily to obtain the requisite clearance or angle.
The sides of the cutting tool must be inclined from a vertical
line, the amount depending upon the diameter of the screw and
the pitch of thread. The inclination of clearance may be ob-
tained as shown at C.
FIG. 72 ANGLES FOB SQUARE THREADING TOOLS
The line ab is vertical and at right angles to cd, and in length
is equal to the circumference of the root of the thread. On cd
lay off the point e a distance from a corresponding to the pitch
of the thread. The line be represents the angle of the side of
the thread. To insure sufficient clearance for the tool the side
angle of the tool should be greater than the line drawn.
FINISH-TURNING WITH STELLITE
It is generally conceded that Stellite is not adapted to finish-
turning steel shafting of any description. We have found
lately, however, that we can produce an excellent finish at much
greater speed than any other tools known, Fig. 73 showing
how the operation was accomplished.
All of the particulars outlined are essential, as by eliminating
any one of them it is impossible to get the proper results.
ENGINE LATHE
103
First we took a very broad-nosed tool, set the cutting edge
about Vs in. above center, giving it an angle of about 10 deg. for
rough turning and 20 deg. for finishing-turning. We did this
on an ordinary shaft-turning lathe, the tools being 2 x % x 4 in.,
using our No. 2 Stellite at a surface speed of 97 ft., depth of cut
%2 in. and feeding 3 ft. per minute, turning six 30-ft. shafts to a
0.001 in. limit with one grind.
-TttAVEL OF BAR
CUTTING EDGE-..
STELLITE TOOL
TOP FACE OF
TOOL
ANGLE -A
10' for Rough Turning 20 'for Finish
Cuffing Edge % above Confer
for Rough and Finish
C
Chip Cis improper and i$
fhe Result of using flat
Broad Nose Tool
wifhouf Rake
RECORD OF PERFORMANCE.
Work - Open Hearth Sfeef Shafting
Machine - Shaff Turning Laf he
Tool - 2*5o-x4 StelliteNo. 2
Surface Speed- 97 Feet
Depth ofCut - !/32*
Feed - J Feef per Minufe
Re.marks - Six-30 Feef Shaff s turned
to 0.001 LJmif with one Grind
To get the reguired Polish and
hold Shaft fo Size Edge of Toot
must taper back towards Center
as shown at "D "so that back
Side of Tool fakes a very Light
Shaving Cut fuming Chip 0$
shown inB
FIG. 73 FINISH BURNING WITH STELLITE
To produce this result we tapered the tool back, as shown at
A, giving it %2-in. taper about I 1 /* in. back. This leaves the
tool cutting the full 1V4 in. and dragging the other % in. with a
side rake sufficient to cut a chip shown at B. We found that the
shape indicated at C was incorrect and was the result of using a
flat, broadnosed tool.
SELF-CENTERING WORK CARRIER FOR USE IN
A STEADYREST
Fig. 74 shows a self-centering work carrier, or chuck, de-
signed for the purpose of supporting unfinished bars of round
section in the steadyrest when the number of pieces required is
104 AMERICAN MACHINIST SHOP NOTE BOOK
too large to warrant centering each piece and turning a place
for the steady rest jaws and yet requires too accurate internal
work to allow them to be run upon the rough surface of the bar.
The illustration is almost self-explanatory. The outer ring is
of cast iron turned on the outside to receive the jaws of the
FIG. 74 RING CHUCK FOR THE STEAD YREST
steadyrest, and on the inside a portion is threaded for the pres-
sure ring, while the remainder is bored taper to fit the outside
of the split clamping ring.
A clamping ring is required for each size of stock to be used.
To tighten the carrier on the stock the outer ring is held by a
spanner while the threaded pressure ring is turned in by a sec-
ond spanner.
QUICK REPAIR FOR TAIL SPINDLE OF LATHE
Fig. 75 shows a quick-repair nut for the tail spindle of a
lathe. I have charge of a number of lathes and cannot have
them down very long for repairs, therefore I keep three of these
nuts in stock at all times and a repair is made in 10 minutes.
Part A fits into part B and part C screws into part B against
part A. A key in part B prevents part A from turning, and
part C has a flat ground on it to let part B pass over the key
that is in the tailstock. The reason for this flat is that the key-
way in part B breaks through into the threaded hole.
ENGINE LATHE
105
FIG. 75 RENEWABLE TAIL SPINDLE NUT
QUICK METHOD OF THREADING SMALL CAST-
BRASS RINGS
Having several thousand small cast-brass rings upon which
to cut external threads the writer proceeded to do the work in
the manner shown in Fig. 76. The ring had a division
through the center, which furnished a ready means of holding.
A threading die was made from a square piece of steel and held
FIG. 76 THREADING BRASS RINGS
in the chuck of the speed lathe while the rings were fed up to
and through the die by the hand-operated tail spindle,
The operation was continuous, the rings being fed clear
through the die and dropped out of the opening between the
chuck jaws. To prevent the rings from being thrown by the
chuck a guard of wood was built over it, and far enough away
106 AMERICAN MACHINIST SHOP NOTE BOOK
to prevent jamming an opening is left at the bottom for the
rings to roll out.
IMPROVED LATHE CENTERS
A lathe center with a high-speed-steel insert seems to be little
known except by those who have had trouble with carbon-steel
centers. I have used centers of this material for eight years
on speed and engine lathes up to 87 in. swing and upon various
grades and weights of work up to 2500 lb., and during this
period I have experienced no trouble from centers softening or
seizing and wringing off in the work.
FIG. 77 STELLITE LATHE CENTER
I always use a plain center without oil grooves, and on heavy
pieces I cut three narrow V-shaped grooves in the work.
Another writer adds : I would also mention that excellent re-
sults are being derived from the use of Stellite tips. Some of
our work is on heavy forgings and we have had difficulty with
burned centers.
The center shown in Fig. 77 has done away with this burning
and there is little or no "ringing." Stellite has heat-resisting
qualities superior to the best of high-speed steels. It is brittle,
ENGINE LATHE
107
but with ordinary care this characteristic is not a hindrance.
The base of the tip is ground so that a good shrink fit will
result when inserted into the shank. Any sized tip can be made,
but one fitting a %-in. hole % in. deep has given us satisfaction.
The tip can be made to protrude V& in. or it can be finished flush.
In case of the protruding tip the work will always be away from
the carbon steel. Where oil is to be used a groove extending to
the point is ground on the face.
CUTTING COARSE-PITCH SCREWS
I once had to rig up to cut a 2%-in. pitch thread on a 24-in.
lathe with a four-pitch lead screw and no change fears for
threads coarser than %-in. pitch.
The only gears available for special rigging were a pair with
cast teeth of l^-in. pitch and having a ratio of 2% to 1. In
FIG. 78 COARSE THREAD CUTTING RIG
order to use these I had to have a screw of 1-in. pitch. This dif-
ficulty was overcome by making a new lead screw with a pitch
of two threads per inch, which was substituted for the regular
lead screw in the lathe. The nut was then babbitted to fit it,
and with the lathe geared as it would have been to cut two
threads per inch with the regular four-pitch lead screw, a left-
108 AMERICAN MACHINIST SHOP NOTE BOOK
handed 1-in. pitch thread was cut on the end of a piece of
l^i^-in. shafting.
Fig. 78 will serve to explain the rest. The lM6-in. shaft was
supported along the front of the lathe by one bearing fastened
to the front of the headstock, and another carried by a trestle on
the floor. The threaded end of the shaft ran in a babbitted
nut fastened to the top of the lathe carriage, as shown. In
order to furnish a satisfactory drive with reverse motion, the
countershaft with its cone pulley and drive pulleys was turned
end for end in its bearings. The drive pulleys on the lineshaft
were shifted to line with the countershaft pulleys in their new
position.
The larger of the two gears was bolted to the faceplate, and
the smaller one was keyed to the l^ie-in. shaft, on which was
also mounted a 30-in. driving pulley, which was belted to the
small step of the countershaft cone pulley. As the lathe was
driven from the shaft which also acted as lead screw, there was
no unusual stress on the lathe parts, and a heavy cut could be
taken without danger of breakage. I believe the most unusual
feature of the job was the making of the special lead screw with
which to thread the iWe-in. shaft.
Another method is as follows:
CUTTING A WORM OF RAPID LEAD
After reading of some of the methods employed by others in
cutting screw threads of very coarse pitch, when the lathe avail-
FIG. 79 THE WORK
able is not especially adapted to this class of work, the writer
desires to describe the means he used to accomplish this purpose.
Fig. 79 shows the pieces required, the threaded portions of
which were a trifle over 514 in. in diameter with double Acme
ENGINE LATHE 109
thread of 4-in. lead. The only lathe available was a 32-in. Pond
with a four-pitch lead screw and a rather weak train of change
gears ; therefore the problem assumed formidable proportions
until the following method was evolved.
The forgings were rough turned all over and then finish
turned at all points between the faces of the collars, leaving the
outside ends Vs in. large. We next made a bushing 14 in. long by
5 in. in diameter and bored it to a slip fit over the long end of
the forging, drilling and tapping it for ten %-in. hollow-head
setscrews. The bushing was then cut with a double square
thread of 4-in. lead, the same as the worm to be cut.
With this master screw, as it had now become, in place on one
of the forgings a casting suitably chambered to receive babbitt
was placed over the screw and bolted to the carriage and a bab-
bitt nut cast around the master screw.
With this arrangement we were able to proceed with the
thread cutting in a very satisfactory manner, even less trouble
being experienced than if a lathe with suitable lead screw and
gearing had been used, for if the dog slipped no harm was done
as the work and the master screw stopped or revolved together.
After one thread of the worm was cut it was necessary only
to run the nut off the master screw and enter it upon the other
lead in order to cut the other thread. As the smallest diameter
of the nut would go over the tail spindle this could be done with-
out releasing the work from the centers.
NONSLIP EXPANDING MANDREL
Fig. 80 shows a positive-drive expanding mandrel which was
designed and constructed by the writer for the purpose ~? ^B-
ishing some special bronze bushings, 18 in. long, 4%6-in. bore,
4 1 %6 in. in diameter, with a 6-in. diameter by %-in. head or
flange on one end, and having three equally spaced oil grooves,
Vs x Vik in. deep broached clear through.
A holder of cast iron is bolted to the faceplate of the lathe
and bored through to fit loosely over the mandrel. The taper
pin passes loosely through the mandrel, serving as a driver and
also holding the mandrel in place while changing the work.
The mandrel B has two tapers as shown, and is threaded at a
point midway between them, A corresponding sleeve C finished
110 AMERICAN MACHINIST SHOP NOTE BOOK
to a nice fit in the bushings, has three slots cut in each end to
a point about 1 in. from the center, and has one % x %2-in. deep
groove cut the whole length on the outside.
In operation, a piece of }6-in. drill rod is laid in this groove
and the sleeve slipped into a bushing, one of the oil grooves
covering the wire. The sleeve and bushing are then slipped
over the mandrel, the thread run up by hand, the tail spindle
brought up to place and a cut started. As soon as the tool takes
hold, the bushing turning the sleeve through the medium of the
wire in the oil groove, makes up the threads and expands the
sleeve until the friction is sufficient to drive the work.
I
I
32'
-Jr-
ifc.
J*DRILL
/6*
iM
^n
-1
r**:
6 R.H. Threads
r ~--*\perInch.
H
WRENCH
FIG. 80 DETAILS OF NONSLIP MANDREL
To release the work, the wrench is slipped on the head of
the bushing with the V-shaped part in one of the oil grooves;
the bushing is then turned back about one-half turn, when it can
be taken off and the sleeve run off by hand ready for the next
piece.
For this work, this mandrel has several advantages over the
standard, four-blade expansion type : as the centers remain true,
the work cannot slip, and only the bushing need be lifted into
and out of the lathe. As the bushing is made in a single piece
with three saw slots 120 deg. apart at each end and not in three
individual pieces, one is not bothered by having it come apart
or by accidentally mis-assembling it,
ENGINE LATHE 111
SETTING A TAPER ATTACHMENT BY MEANS OF A
DIAL INDICATOR
My method of setting the lathe for turning tapers of various
kinds is if possible to secure a piece having the same taper as
the one to be cut an end-mill, taper shank reamer, or similar
tool. With this on the centers of the lathe and the dial indicator
in the toolpost I adjust the taper attachment until the indicator
will pass along the sample piece without movement of the
pointer.
If no sample is obtainable I put a parallel piece on the centers,
mark off a convenient distance, say 6 in., and adjust the taper
attachment until the difference in the readings of the indicator
at the two marked points equals the sine of half the included
angle of the taper, calculated to a radius represented by the dis-
tance between the marked points. This method is equally serv-
iceable in setting either the taper attachment or the compound
rest for boring a taper hole in the lathe.
ARC-FORMING ATTACHMENT FOR LATHE AND
SHAPER
Figs. 81, 82 and 83 show an attachment for forming radii on
different kinds of work. It can be used on a shaper, a lathe and
other machines, and if properly operated, good results are ob-
tained. The mechanism may be best understood by studying
Fig. 81, which shows the principle. The base A carries a slide B,
and at right angles to this is a slide C on the member D. Also
mounted on the base A is a worm gear E operated by the worm
and handle. The worm gear is provided with a slot G passing
through its center. In this slot is a stud H, which can be ad-
justed and secured at any distance from the center of the worm
gear, within the confines of the slot. The upper end of this stud
bears in a hole in an arm I secured to the top slide C.
For the sake of demonstrating, two pencil holders J are se-
cured to the slide C. If the worm wheel E is caused to rotate,
the pencils K will duplicate the path described by the center of
the stud H around the axis of the wormwheel G. In this way,
boring or turning can be done as indicated diagrammatically in
Fig. 82.
112
ENGINE LATHE
113
In Fig. 83 is shown the outfit as designed for use, and also some
forms of tools with inserted cutters. Referring to Fig. 83, the
sliding block A is mounted on a screw B. The amount that A
is off center determines the diameter of the circle to be turned
or bored. The block A is set by means of a socket wrench C
inserted through the hole D when the end of the screw B is in
line with the inner end of the hole D. Two pins E and F are
provided for ascertaining how much the block A has been set off
center. The pin E is secured to the tool slide, while F is sta-
tionary in the bottom slide.
OLD LATHE USED AS A BROACHING MACHINE
An old hollow-spindle lathe that was no longer in use was
made into a broaching machine in the following manner:
A nosepiece A, Fig. 84, was turned and fitted to the spindle.
FIG. 84 LATHE AS A BROACHING MACHINE
The inside of the nosepiece was threaded to take the lead screw,
which carried the broaches. Bushings in the tailstock sup-
ported the outer end of the lead screw. The carriage was tight-
ened to the lathe bed, and behind it a heavy angle plate was
fitted as a bolster for the work.
This arrangement made a good machine for broaching out nu-
merous shop jobs.
Another broaching job was done in the lathe as follows:
BROACHING HOLES ON THE LATHE
The special toolpost for broaching on a lathe shown in Fig.
85 is intended only for toolroom work, and is designed to pro-
vide a method of accurately cutting square or other shaped holes
in work not requiring duplication.
114 AMERICAN MACHINIST SHOP NOTE BOOK
The external shell A is turned out of a solid block of steel of
the shape of the base B, and drilled to receive bolts for attach-
ment to the cross-slide C. This shell is bored out and threaded
to receive the toolholding post. The shell A and post are slotted
as shown, to receive the tool E, the slot in the shell being elon-
gated to permit the vertical movement of post and the tool which
it carries.
On the projecting upper end of the post, is a nut F, having
FIG. 85 TOOLPOST FOE BROACHING HOLES IN THE LATHE
a series of openings, in any one of which may be inserted a short
rod or pin G, by means of which it may be turned to raise or
lower the toolpost. The nut F, rests on a ring or collar H, which
is clamped to the shell A, by means of the setscrew /. The ver-
tical movement of the toolpost is obtained by turning the feed
nut F.
The tool E is secured in position by a long setscrew J, which
is located in a threaded opening in the toolpost.
In operation, the work is clamped in the chuck of a lathe and
indicated by means of the chuck jaws. The lathe spindle is also
clamped in position as needed. The hole to be broached is first
bored round, then by feeding the lathe carriage lengthwise on
the bed, and also feeding the cross-slide in the right direction
ENGINE LATHE 115
on its ways, a cut is started. In obtaining the vertical feed,
the special toolpost described is brought into operation.
SIMPLE CALCULATION OF CUTTING TIME
A great deal has been said and written upon this subject;
elaborate tables have been compiled; constants involving the
calculation of speed expressed in terms of feet per minute have
been worked out until the subject would seem to be exhausted.
The average mechanic does not take kindly to calculations of
this kind, and cutting speed thus expressed does not appeal to
him, but if he be a wide-awake fellow he will give the tool what
it will reasonably stand expressed shall we say, in certain lever
positions, belts on certain cone-steps, or more briefly in revolu-
tions per minute.
The mechanic, however, is interested in knowing how long it
is going to take to finish the piece in hand; and if his lathe or
milling machine is supplied with index plates showing revolu-
tions per minute and feed constants for the various lever posi-
tions, the following simple calculation will suffice :
Let us say he has a cut 8 in. long (diameter does not matter)
and his index plates show the spindle speed to be 55 and the
feed 32, he simply multiplies the length of cut by the feed, and
divides by the revolutions per minute thus :
8X32
= 4.65 +
55
indicating that the tool will make this cut in approximately 4.65
minutes.
A FLOATING REAMER HOLDER
The writer has had an opportunity to try a number of forms
of floating and so-called floating reamer holders. Some work
well until worn, others work indifferently from the start. We
have adopted the form shown in Fig. 86, as being equal, if not
superior, to most others, especially for hot-rolled or other tough
steel work. It has been our experience that reamers give more
trouble in this material than in either cast iron or brass.
The steel reamer R fits the standard ^-in.-per-ft. taper on the
116 AMERICAN MACHINIST SHOP NOTE BOOK
holder D, and is driven by the two keys K. The holder is bored
Ha in. over the size of the small diameter of shank S, giving this
amount of float. Holder D is drilled out beyond the counter-
bore to a suitable size to admit the hardened thrust plug T, and
the steel ball. A similar hardened thrust plug is supported in
the end of shank 8. The counterbore for the ball allows about
^2-in. play, and the holder and shank are kept separate laterally
by the same amount. The entire thrust is taken by the ball and
thrust plugs, allowing the reamer to follow the hole with very
little effort.
Several forms of floating drivers were tried, but the two shown
FIGS. 86 AND 87 FLOATING REAMEB HOLDEBS
work best. In Fig. 86, the drive is by a hardened pin P, a drive
fit in shank S, but having ^2-in. play in the holes in the driver.
This works well for smaller size reamers, but wears out more
rapidly than the form shown in Fig. 87. Here the drive is taken
by the shackle ring 0, which is the standard Oldham coupling
drive.
JIG FOR TURNING ENDS OF SQUARE TOOLS
Fig. 88 shows a jig for use in turning 1-in. square tools
on both ends. The jig A is of machinery steel and accom-
modates eight pieces of stock. It is 3 in. square and 10 in. long,
and has a horizontal slot extending through it which receives the
stock to be turned. The stock projects beyond the faces of the
jig. The openings (7, E and F in each end are for the purpose
of receiving studs to be carried on the centers. There are eight
ENGINE LATHE
117
holes Z>, tapped in the upper face of the jig to receive safety-
head setscrews which hold the stock in place for turning. After
the stock is secured in position, the jig is placed in the lathe with
the center studs at C, and the stock turned to length; then the
FIG. 88 JIG FOR TURNING ENDS OF SQUARE CUTTERS
center studs are moved to E. Turning the stock from this cen-
ter position puts cutting clearance on one end. The center studs
are then moved to F. Turning from this position puts clearance
on the opposite end. A cutter with clearance on both ends is
shown at G. This jig is also used for grinding the cutters, and
has proved satisfactory.
GANG TURNING FIXTURE
Fig. 89 shows a fixture fo^ turning several small pieces to
a given radius. The old method was to drive the work into the
FIG. 89 GANG TURNING FIXTURE
118 AMERICAN MACHINIST SHOP NOTE BOOK
grooves. They had to be driven out from the back of the face-
plate when finished, and the work did not come true. The fix-
ture had to be made out of malleable iron or steel. I devised the
means shown of clamping the work with special T-head bolts.
This method has proved very satisfactory and does not distort
the work. The fixture is made of cast iron, and the work can
be put in and taken out in much less time than formerly. The
same method could be used with other kinds of work, provided
the lower part is larger than the upper.
THREAD-CUTTING TOOL
The cutter head swivels at A, Fig. 90, and is set to the angle
lead
of the helix, - = tangent of helix. The
pitch diameter X 3.1416
screw B adjusts the tension of the spring C, the screw D acts as
FIG. 90 THREAD CUTTING TOOL
a stop, so that the cutter will return to proper position after the
cut; E is the lock-screw by which the tool may be locked for
roughing external threads and to hold the tool rigid for internal
cutting, using the cutter bar as shown in the illustration.
The great advantage of this tool is that the circular cutter
may be removed from the holder for sharpening and be returned
accurately to its position. The spring feature also insures a
smooth, well-formed thread, so difficult to obtain with the fixed
tool.
Any excessive cutting pressure is taken care of by the spring,
when locked the tool is as rigid as a solid one.
ENGINE LATHE
119
CHUCK FOE NIPPLES AND STUDS
Fig. 91 shows an efficient chuck for nipples and studs. The
body A is threaded to a shoulder to receive various sizes of
nipple holders B and is slotted and bored for the wedge C and
the plunger D respectively. The shank of the body A is turned
down to facilitate chucking when the pipe machine is used.
FIG. 91 CHUCK FOB NIPPLES AND STUDS
In operation, the wedge C is first driven home, thereby forcing
the plunger D against the inner face of the nipple holder; the
nipple is then screwed into place and the thread cut. To release,
the wedge is loosened by a light blow, thus taking the pressure
off the plunger, when the nipple can be easily removed by hand.
CORRECTING UNTRUE CENTER HOLES
I was given a job, one day, of turning down the end of a shaft
to receive a gear. After swinging the shaft up on lathe centers,
I found that the center holes had been drilled and reamed nearly
%2 in. off center, as shown at A, Fig. 92. There was but one
remedy, and that was to correct the position of the center holes.
The following method was successfully employed in doing this:
120 AMERICAN MACHINIST SHOP NOTE BOOK
One end of the shaft was gripped in a chuck having four inde-
pendent jaws; the other end was held in the steadyrest. The
shaft was trued up nicely. A center-finding tool B, with one
cutting edge, was placed in the toolpost, and with it a conical
hole greater than 60 deg. was machined in the end of the shaft,
as shown. Next, a half-round reamer C, having its cutting edge
FIG. 92 CORRECTING UNTRUE CENTER HOLES
on the front end only and a diameter greater than the diameter
of the conical hole at the point where the drilled hole breaks
through, was made from drill rod. When ready, it was placed
in a drill chuck and fed into the end of the shaft, by using the
tailstock. Finally, the conical hole was brought to the proper
angle by reaming with a standard center reamer D. The shaft
was then removed, turned end for end, and the same operations
performed.
PISTON-GROOVE SIZING
By adopting the following method for an unlimited number
of automobile pistons to be grooved to a limit of plus or minus
0.0005 in., very satisfactory results were obtained. They were
ENGINE LATHE 121
roughed out in the usual manner on a screw machine, leaving the
grooves, four in number, about 0.015 narrow and the outside
diameter about V\Q large, then they were passed on to an engine
lathe and finish turned to grinding size. The next thing on the
program was to finish the grooves to size.
The piston was run between centers at not too hasty a speed,
and a square-nosed tool the exact width of the groove was run in
to the required depth. All would proceed well until a few pis-
tons had been finish grooved, and then the tool would begin to
cut small, so that the low limit gage would not go. This, of
course, ordinarily necessitated a new tool being ground up.
After grinding quite a number of tools, it became evident that
some scheme must be found to save these pieces of %-in. square
tool steel.
The idea suddenly suggested itself to peen the tools as they
became small, instead of taking them out of the toolholder. By
a very slight tap with a small hammer the trick was accom-
plished, and our trouble vanished. When a tool showed signs of
wear, all that was necessary was a light tap with the hammer.
In this manner it was possible to finish piston grooves day in
and day out with scarcely a stop. Practically every groove was
made a perfect fit for the piston rings, which were finished to
size on a surface grinding machine.
SECTION VI
THE MILLING MACHINE
TOOL FOR LAYING OUT WORK IN THE MILLING
MACHINE
FIG. 93 shows a device which I find very helpful in laying
out work on the milling machine where a series of holes is to be
located at different points. The body of the tool has a hole to
fit the arbor of the milling machine, and at a right angle thereto
is a smaller hole to which is fitted a small prick punch held in
position by a collar and spring as clearly shown in the sketch.
Hole to fit Arbor
. of Milling Machine
FIG. 93 TOOL FOB LAYING OUT WORK IN THE MILLING MACHINE
To use the tool it is clamped tightly on the arbor in the same
manner as a cutter, care being taken to have the body set square
with the table. Fasten the die blank to the milling-machine
table and spot the center. Then by means of the indexes on the
traverse and cross-screws any number of holes can be laid out in
quick time and to good advantage.
CROWNING PULLEY FACES ON THE MILLER
In a shop the line of manufacture of which included large
quantities of cast-iron pulleys, the turning of the crown face
122
THE MILLING MACHINE 123
got to be a considerable item of labor expense, as it was a slow
operation and required closer attention because of the crown.
A fixture, or machine, like that shown in Fig. 94 was made,
and its success was immediate.
Except for changing the pulleys and starting the cut the
machine takes care of itself, and having finished a pulley (which
it does in one revolution) it will run merrily along without dam-
age until somebody gets ready to put on another casting.
FIG. 94 CROWNING PULLEYS ON THE MILLER
It was made the duty of everyone, from the floor sweeper up,
whenever he passed one of the machines that was running idle to
take off the finished pulley and start a new one. Thus the labor
cost was brought to a very low figure as the changing would
almost always be done by someone who was waiting for a cut to
run out on the milling or planing machine or by someone who
for one reason or another could spare a moment without inter-
fering with his regular work.
The drawing is self-explanatory. The diameter of the in-
serted-tooth cutter and the relation between the center lines of
124 AMERICAN MACHINIST SHOP NOTE BOOK
the two shafts is so computed that the path of the cutters will
leave the requisite amount of crown.
Whenever a man sees a machine idle and he has a moment to
spare he simply turns back the handle A a turn or two, loosens
the nut B, takes off the finished pulley, puts on a casting and
runs up the cutter again to a fixed stop, at which time it is cut-
ting the full depth required to size the pulley.
AN ADJUSTABLE V-BLOCK
Fig. 95 shows an adjustable Y-block I am uj^ng for mill-
ing the surface of the casting shown in place in the sketch.
The best means of locating the work seemed to be by a V-block ;
FIG. 95 ADJUSTABLE V-BLOCK
a solid one was tried, but gave trouble on account of excessive
variation in the diameter of the boss on the castings, so I con-
ceive the idea of making it adjustable, as shown, to compensate
for variations. Adjustment is by means of setscrews A.
DOING A LARGE JOB ON A SMALL MILLING
MACHINE
Several castings were to be machined, as shown in the upper
right hand corner in Fig. 96. The work was ordinary shop
THE MILLING MACHINE
125
practice up to the point of cutting the slots across the face of the
rim. A formed cutter was plainly the only tool to use that
would insure interchangeability of the pairs of slots two adja-
cent slots constituting a working pair in the special machine of
which the wheels were to be a part. A limit of 0.008 in. was
allowable in the spacing of the pairs of slots. The only machine
FIG. 96 DOING A LARGE JOB ON A SMALL MILLING MACHINE
available for the slotting was a No. 2 plain milling machine
which was in good condition, but too small for such a job.
After the, lathe work was finished, the rim was carefully laid
out into 20 divisions, using a glass to secure accuracy and a line
to indicate working depth marked before removing from the
lathe. For each pair of slots milled, the wheel was set by the
division marks from a fixed point on the face of the milling ma-
chine, again using the glass to insure close work. The finished
parts showed this method to be quite accurate enough.
The castings were laid in a horizontal plane on the table of
126 AMERICAN MACHINIST SHOP NOTE BOOK
the milling machine and the vertical (hand) feed used for cut-
ting. A casting that served as a center stud and baseplate was
made and the work was placed upon it. A parallel under the
front and a clamping bolt completed the arrangement.
Owing to the size of the wheels the table had to be run out to
its limit, causing it to overhang to such an extent that would
have rendered feeding not only difficult but would have imposed
serious strains upon the machine itself. The castings weighed
600 Ib. each, nearly half the weight of the machine. To avoid
trouble, the simple counterbalancing scheme shown in the draw-
ing was adopted. An eye-bolt was screwed into the center stud,
to which was fastened a rope that passed over two grooved
pulleys and down in the rear of the machine to a counter-
weight. The weight was made 80 Ib. heavier than the wheel
casting and attachments. With the aid of this counterbalance
the loaded table could be run up and down as easily as when
empty and the possibility of distortion was removed.
The work was done with the formed cutter shown to the right.
The body is of soft steel milled out for three blades which are
held in place by two taper pins each. The blades were put in
place in the blank body and the form turned on both. To give
them the necessary clearance the blades were removed and Vs in.
was turned off the body. For hardening and tempering, the
blades were replaced and the complete cutter treated. The
finish and accuracy of the job produced were all that could be
desired; the working time was within the bounds of good prac-
tice, and there was no great outlay for special tools.
THE MILLING-MACHINE VISE AS A SPECIAL
MILLING FIXTURE
In most cases in repetition work a man can work much faster
by using a quick-acting vise which is operated by lever and
eccentric instead of a screw. I much prefer to have two ver-
tical Vs, one near each end of the jaw ; this results in increased
speed of operations, and puts a more equal strain on the vise. I
have aways made the horizontal V as shown at A in Fig. 97.
This clearance at the upper part of the jaw renders it much
easier to load and unload the vise because when the vise is open
the work can be dropped into position where it will be definitely
THE MILLING MACHINE
127
located by the lower part of the V. If the jaw is of uniform
thickness it too often happens that the work, especially if a short
piece, falls between the jaws, resulting in loss of time and in
annoyance.
Many times in milling flat surfaces, oil grooves, keyways, etc.,
in shafts or bolts, it is not possible to locate these parts with a
shoulder against the jaws as the pieces to be machined may then
FIG. 97 MILLING MACHINE VISE JAW AND WORK STOP
project too far, resulting in chattering, or else may be too close
to the jaws for the cutter to pass.
For all these cases, and they probably form the majority, I
have used the tool shown at B with very satisfactory results.
The base of this tool is provided with a slot so that it can be
clamped to the milling-machine table in any position. The stud
is threaded at one end so that it may be turned to any desired
position and then secured by means of the locknut. The stud is
about as high as the top of the vise ; it has two flat surfaces which
form a knife edge, slightly rounded.
128 AMERICAN MACHINIST SHOP NOTE BOOK
Whenever a milling operation has to be located accurately in
relation to a shoulder the knife edge is used as at (7, and no
matter what variations there may be in the length of the pieces
the relation of the milling operation and the shoulder used for
locating will be absolutely uniform.
SETTING ANGLE FOR FLUTING TAPER REAMERS
A very handy shop kink is shown in Fig. 98 for the angular
setting of milling-machine centers to insure even width of the
land when fluting taper reamers.
Tables in various handbooks give the values of these angles
for angular cutters, but only in increments of 5-deg. included
SECOND POS/T/Qff
FIRST POSITION
Scribe Line with
Surface Gage
Index
one Flute
with dividing Head
FIRST CUT
FOURTH POSITION
Adjust Centers until
this Line is Parallel
/ with Table
. gg SETTING ANGLE FOB FLUTING TAPER REAMERS
angle of the piece to be cut, while in the case of taper reamers
this angle is more than likely to fall between the given settings.
Again, if the angle of the fluting cutter is changed the set
angle must also be changed, whereas with my method the setting
is independent of the angle of the fluting cutter, and further-
more one can set up a taper reamer or cutter by this method in
the time that he is looking up the table.
By the cut-and-try method the toolmaker will make from
four to six cuts (two for each trial) while with this method he
can cut full depth the first time.
The sketch needs little explanation. With the centers in par-
allel position and a surface gage set to the center height draw a
THE MILLING MACHINE 129
line on the surface of the reamer to be cut (first position).
Turn the dividing head one-quarter turn until this line is at the
top (second position) ; then index back one tooth to third position.
Now raise the dead center until this line is parallel with the sur-
face of the table, testing for parallelism with the surface gage.
It will readily be seen that this line represents the edge of the
tooth next to the first one to be cut and that it will parallel the
path of the fluting cutter.
POINTER TO SUPPLEMENT TABLE-FEED STOP ON
MILLING MACHINE
The automatic stops furnished with our milling machine do
not always operate at exactly the same place. In milling key-
ways with a narrower cutter than the keyway, etc., it makes a
better-looking job to stop at exactly the same place at each cut,
so I made up a pair of adjustable pointers, as shown in Fig. 99,
FIG. 99 POINTEB TO SUPPLEMENT TABLE STOP
about 1 in. long, the pointer reaching to the saddle of the ma-
chine, upon which I made a line.
I set the pointer at the desired stopping place and watch it
until it comes nearly to the line, then trip the feed and turn the
screw by hand to zero on the dial plate. A second pointer that
has been set in the same manner for the starting cut is a further
convenience.
130 AMEEICAN MACHINIST SHOP NOTE BOOK
A dial indicator mounted on a bracket attached to the table
slide and acting in conjunction with a stop attached to the miller
table will be found exceptionally accurate and convenient for
gaging the travel of the table.
CHART FOR DETERMINING APPROACH FOR
MILLING CUTTERS
The chart shown in Fig. 100 is very simple.
Diameter of Cu-M-cr
4 I I j, Length of Approach
FIG. 100 CHART FOR DETERMINING APPROACH FOR MILLING CUTTERS
The formula at the top of the chart can be more simply ex-
d
pressed by I = cosine A X -
2
ADJUSTABLE LOCATING BUTTON
A button or locating bar that can be adjusted to run dead true,
is an exceptionally handy article on a milling machine or boring
mill where accurate center distances are to be located. The bar
BUTTON
FIG. 101 ADJUSTABLE LOCATING BUTTON
THE MILLING MACHINE
131
is made in two parts consisting of shank A and button B. The
part A is hardened all over and is ground square with the axis of
A at C, and the button is ground and lapped to size. In use,
the button is adjusted to run true by means of the four screws
on the periphery.
BORING A HOLE AROUND A CORNER
If a man should ask you to design some means of boring a
hole around a corner, you would probably wonder if he had not
"fallen off the wagon. " At least, that is what passed through
my mind when the chief put the matter up to me in just such a
manner.
CUTTER CUTTER
FIG. 102 BORING A HOLE AROUND A CORNER
The blueprint boy suggested using a rubber drill ; but strange
as it appears, the chief rejected the idea, much to the surprise
and consternation of the kid. However, a glance at Fig. 102
will convince you that the problem is not as difficult as it sounds.
The work is a bronze casting with a 19i6-in, hole bored on a
132 AMERICAN MACHINIST SHOP NOTE BOOK
radius to fit a bent copper pipe. This casting has been milled to
the required thickness, and two %-in. holes have been drilled
previous to the boring operation. The center hole is cast out
with sufficient metal left to finish out in boring.
The fixture is a steel casting with generous base for clamping
to the table. At A is a wormwheel, also of cast steel, with teeth
halfway around in the direction of the arrow from the point B.
This wheel has a iug cast on it to which the work is clamped,
and is held to the base by a stud, which is keyed to it and
held by a nut and washer. At D is the worm keyed to the
crank E and held in position by two collars F pinned to the
crank.
The bottom of the cutter should be on the center GG, and the
sides H should be ground so as to clear the work as the hole is
being bored.
There are two studs for clamping the work, which are used
with slotted washers / and hexagon nuts and washers on the
other end. The diameter J is made to slip through the %-in.
holes in the work. In use, the work is clamped by the studs at
L, with the center line of the cutter in the correct position.
Then the handle is turned and the work slowly fed upward, bor-
ing the hole.
EFFICIENCY IN MILLING FIXTURES
No greater precision is required on any machine work than
on aviation engines, and it is interesting to note the provisions
which are made for extreme accuracy and rigidity in the design
of tools and fixtures for this work. Here are a few features in
the design of milling fixtures which are worthy of note and
imitation.
The work is never allowed to bear on the cast-iron surface of
the jig if the operation demands any degree of accuracy. Hard-
ened steel strips or pads are provided under all bearing points,
as shown in the upper left hand corner in Fig. 103.
Locating pins are designed as in Y, especially those of the
smaller diameters. A pin of uniform diameter will invari-
ably get bent or battered out of alignment, but a pin like the
one shown is good practically all the time. The large diameter
is a drive fit in the jig casting, the smaller diameter is hardened
THE MILLING MACHINE
133
and ground to size, and the shoulder which is lapped to a true
surface, insures the pin being kept in place.
A cutter which is used in place of the interlocking cutter is
shown to the right. When interlocking cutters are worn they
are ground and then packed up between the halves to maintain
the original size of the face of the cutter. The one shown in the
illustration is merely an inserted blade cutter. When it becomes
dull it is reground and then every blade is offset to one side, so
that the width of the cut can always be held the same.
FIG. 103 VARIOUS MILLING KINKS
When cutters are adjusted, or are adjustable, the spacing be-
tween them changes. This is taken care of by means of the
adjustable spacer sleeve as shown at the bottom in Fig. 103.
It is merely a sleeve A bearing against one cutter and threaded
for a nut B, which is turned by a pin in the holes C, and another
solid sleeve D bearing against the other cutter. The only mem-
ber which turns is the nut and this eliminates any wearing of
sleeves against cutters.
AN ADJUSTABLE SIDE-MILLING CUTTER
This cutter is made in two parts ; the adjacent sides are on an
angle when assembled, as shown at A and B in Fig. 104.
This is done in order that the cutter, when opened by a washer
located in the center between the faces C and D, may be kept to
proper thickness after it is ground. The reason for making the
134 AMERICAN MACHINIST SHOP NOTE BOOK
adjacent sides of each part on an angle is that when the cutter
is ground, and a washer wider than space CD is used, there will
be an opening ; and were the sides straight, a ridge would be left
on the work. The parts are held together by two dowels E and
F, in the recesses G, having their ends beneath the cutting sur-
face.
In making these cutters the first thing done is to make the
holes in the blanks, and then plane the angles. Each half is then
FIG. 104 ADJUSTABLE SLOT MILLING CUTTER
put on an arbor, and the recess in the center is turned out (faces
C and D). The halves are then put together on a plug and
drilled and reamed for the dowels E and F, after which they can
be turned and milled as a whole in the usual way, except that
care must be taken to keep the halves together. This cutter ob-
viates the use of the expansion interlocking cutter, which is very
difficult to make. This cutter is very satisfactory in use.
A LATHE JOB ON A MILLING MACHINE
A great deal has been written about the adaptability of the
lathe. Fig. 105 shows what can be done on the milling machine
when a lathe is not available. The illustration speaks so plainly
that I think nothing need be said about the job other than to call
attention to the fact, that the work was held for the first opera-
tion by four setscrews, one of which A is shown. These screws
were equally spaced A in the housing, and had their bearing
against the outside of the plate B, which is about 1^ in. smaller
in diameter than the work Z>. A lathe tool C is held in the vise.
In the small shop the miller should be provided with several
face plates the largest of which is the full swing of the miller
with the knee in its lowest position. With these and a tool held
in the vise much chucking work can be done.
THE MILLING MACHINE
135
It is not always necessary to provide means for elevating the
tool to the center height, for large work the vise can be placed
near the end of the table if only the perimeter of the work is to
be turned. Where the work must be faced across the entire face
some sort of rigging must be provided to bring the tool to the
center height of the miller spindle.
FIG. 105 A LATHE JOB ON A MILLING MACHINE
CLAMPING FLAT SQUARED WORK
A very simple one-action clamping device for rectangular
pieces is illustrated in Fig. 106. The principle is shown clearly.
The work is located by the stop-pins and is clamped against
these pins by the screw A and the lever B. It will be readily
seen from the illustration that by turning the clamping screw
the work is forced against the pin D by the screw and against
the pins C and E by the end of the lever F.
When the work is long, the swivel piece H may be
added to the device to insure clamping against both of the pins
on the long edge of the work. This principle also works very
successfully when applied to a plate jig for local work. The
small drill jig using this principle is shown clamped to the
spot X by the screw Y and the lever Z. The advantage of this
device lies in the fact that by tightening one screw we secure a
clamp in two directions at right angles to each other, the clamp
automatically adjusting itself.
FIG. 106 CLAMPING FLAT SQUARED WORK
---- >U ~ 3f" >k Jrf *
FIG. 107 ADJUSTABLE BORING TOOL HOLDER
136
THE MILLING MACHINE
137
ADJUSTABLE BORING-TOOL HOLDER FOR THE
MILLING MACHINE
Fig. 107 shows an adjustable tool-holder which has the merit
of being efficient and at the same time inexpensive.
It consists of the machine-steel shank A bored eccentrically to
receive the tool holder B, which can be clamped in any position
by the setscrew C. The boring tool or drill is carried in the hole
D and fastened by the setscrew E.
In practice the shank is gripped in the chuck usually provided
with a miller. Of course, the shank might be turned some stand-
ard taper to fit a standard arbor, if desired.
For light cuts on jig and fixture work, this tool has been found
very useful; and it is certainly an inexpensive one to make. It
will well repay the cost of material and labor, spent in its con-
struction, where work of the character mentioned above is en-
countered.
MILLING VISE FOR USE BETWEEN CENTERS
Fig. 108 shows a milling vise to be used between centers
and controlled by the index head. A set-up in the old type
of vise takes considerable time, and each angular cut means a
FIG. 108 MILLING VISE FOB USE BETWEEN CENTEBS
new set-up. With this vise, after the work is once set up, it is
possible to take cuts at any angle, as well as bore, drill and ream
at any angle, as the vise is under the control of the index head
at all times.
138 AMERICAN MACHINIST SHOP NOTE BOOK
The mechanic will readily see its usefulness, as a movement of
two spaces on the 18-hole circle gives an angle of one degree.
SETTING TOOL FOR USE WITH MILLING CUTTERS
Fig. 109 shows a small tool that I have found handy for
setting milling cutters or lathe tools to center. It is easily
made and is used on a combination square, as shown, by putting
the head on any graduation and moving the small head to half
the width of the cutter. The small head is made to slide on
FIG. 109 SETTING TOOL FOB USE WITH THE MILLING VISE
the scale of the combination square in the same manner that the
regular head slides. It is square with the blade on the one side,
but the other side tapers at an acute angle from the edge of the
scale to the end where it comes to a sharp point. This facili-
tates setting the cutter either in relation to the slots of the mill-
ing machine, locating point of jigs or fixtures or with relation
to any convenient finished or unfinished parts of the work.
SECTION VII
PLANER AND SHAPER
REPAIRING OLD PLANING MACHINES
I WAS given a free-hand in overhauling a dozen old planing
machines which had been in service from ten to thirty years
and made by various manufacturers. They ranged from 20 in. to
36 in., in size. I found the T-slots and stop-pinholes badly worn
and after measuring both on all the machines, I decided to make
them uniform in order to interchange stops, studs, bolts, angle,
squaring plates, etc. Securely clamping an electric end milling
attachment to the rail head having the largest T-slots I procured
a cutter that would just clean up the bottom, top and sides of
the lower portion of the T-slots, leaving the sides of the upper
portion to be planed later. I then threaded v a 1-in. rod a little
longer than the longest table, drilled and tapped the front end
of each table to a tight fit for the feed screw, and then bushed
and tapped an old 12-in. flanged pulley to fit the screw. I
clamped a big angle plate on the floor, far enough ahead to clear,
with a hole in line with feed screw. I next mounted a 6-in.
pulley on an electric portable drilling machine spindle, and
clamped the drilling machine to the floor with the pulley in line.
I rigged up a wooden horse to support the screw when extended.
With the planing machine drive and reverse belts off, and after
a few trials with different feeds and by regulating the speed of
the portable drilling machine, I milled the T-slots on each plan-
ing machine rapidly and accurately.
The table of each machine was then placed right side up under
a radial drilling machine, and new holes were drilled where
needed, and old and new holes reamed. Large holes were drilled
in the chip boxes to facilitate cleaning. I then inverted the
tables and counterbored each hole twice its diameter, and 1^6
times its diameter in depth. Round nuts were made of cold-
rolled steel with a shoulder turned to clear one-half of the pin-
139
140 AMERICAN MACHINIST SHOP NOTE BOOK
key drill and tap. The nuts were twice the stop-hole diameter
deep on their threaded portion with a shoulder flush with the
under side of the machine table. After pressing in the nuts I
drilled and tapped half-and-half for %-in. pin-keys, which were a
tight fit, and were made of long rods cut off in 12-in. sections,
forced in by a stud nut, sawed off and upset.
Planing the Ways. The ways of each planing machine base
were then trued on a large new planing machine, and the table
ways planed to fit, relieving the rack if necessary. I then planed
the head slides, rebushed the bearings, and attended to all other
needed repairs. Tables were scraped in and run for a week on
rough work, after which I planed the sides and surface, also the
sides of the grooves. I then planed T-nuts in long bars, %2 in.
below table surface, and a loose sliding fit in T -slots. T-nuts
were then drilled in a simple sliding jig, spacing holes three
times a bolt's diameter. I tapped them in long bar lengths in a
small drilling machine, using one roughing and one finishing tap.
The nut bars were then sawed off, making about two dozen for
each planing machine. I next drilled, tapped and turned, then
sawed off a large number of ordinary square head stops with a
heavy-cuffed screw, making stops of various heights up to 4 in.
I tapped these in the same way I did the T-slot nuts, except that
the drilling machine table was tilted to place the setscrews in the
stops on an angle. I also made a number of heavy high com-
bination multi-parallels, stops and planing machine centers,
using 2x6 in. ; 2x8 in., and 2 x 12 in. steel slabs, cutting them
at an angle on the cold-saw, drilling and marking them in pairs
for the setscrews or stop centers. I held them to the planing
machine table by a stud fitting stop-pinhole and a nut at the
bottom of the stop-pinhole. These stops may be used in either
direction, also as angle plates and parallels, and are cheap if
rightly made. I drilled and slotted them for hexagonal nuts.
I made a number of standard angle plates, and in making these
I drilled them for stops as well as bolts, and made the backs
support a standard angle, which I machined. I then made one
long mult if ace angle plate full length of our longest small plan-
ing machine table. With keyway bolt slots, stop-pin holes,
squaring lines, etc.
The studs next occupied my attention and I made them in
large quantities scrapping all the miscellaneous hexagonal and
PLANER AND SHAPER
141
square nuts, and making a large number of double length hexag
onal nuts with wrenches to fit. Nuts were kept on the studs with
the length stamped on the end of each stud, while the stud
dropped through a large plate near the planing machine.
A SHAPING MACHINE REPAIR JOB
Having a 14-in. shaping machine with ways for the ram badly
worn, and having no planing machine available with sufficient
room under the cross rail to permit truing up the ways, and since
the top of the column was not worn, I adopted the following
plan of doing the work : I stripped the shaping machine of ram
and gibs, and secured a bar of cold-rolled steel A, Mg. 110,
FIG. 110 RIG FOE SHAPING MACHINE
1 x 3 in. in the vise, the length of this bar being slightly in ex-
cess of that of the ways. The bar was set parallel with the bear-
ings by the swivel vise. I then employed an old cast-iron bench
plate B, with the flat-nosed tool C wedged in place as shown.
By sliding the plate back and forth guided by the bar A, and
using the cross-feed of the shaping machine, and feeding slightly
at each stroke of the bench plate, a fair job was obtained, arid I
doubt whether or not the shaping machine could have been taken
down, stripped and set up on a planing machine, and the work
done in less time.
MACHINING A LONG RECTANGULAR HOLE
I had a block A } Fig. Ill, of 3Y2 per cent, nickel steel
x 3 x 5 in. Through this block I was required to machine a hole
142 AMERICAN MACHINIST SHOP NOTE BOOK
0.50 x 1.0 in. with an allowance of 0.0005 in. in the sizes. The
hole was to be straight throughout its length, parallel with the
block, and the short sides of the hole square with the longer sides.
It was not permissible to cut the block in half, and mill the
hole in the two parts. Making a series of long broaches, and
broaching it, was out of the question as it would be an expensive
operation, and I had no facilities for hardening and grinding the
cutters, and no press that I could use to push the broach through.
F
FIG. Ill THE WORK AND THE TOOLS
The only machines I had that I could depend upon to help me
out were a 12-in. lathe and a 16-in. shaping machine. With
these two machines my purpose was accomplished. I bolted an
angle plate to the faceplate of the lathe, and drilled two parallel
holes V&2 in. diameter through the block. Before running the
^%2-in. drill through I first drilled two smaller holes half-way
through the block and then reversed it on the angle plate. In
this way I kept the holes parallel. I then clamped the block
down on the shaping machine table and made up a bar as shown
at B. This bar was a few thousandths smaller than the hole and
on it I had put a tool somewhat similar to those used for rifling
gun barrels. This tool was held down on the inclined plane by
a small machine screw, and was held back by the setscrew in the
end of the bar. The chip tended to force it up the plane and
the reverse stroke tended to push it down the plane, thus making
PLANER AND SHAPER
143
it safe to back out at any time. I made up a series of these tools
of different heights, as the amount of adjustment for each was
limited.
Starting with the smallest tool, and cutting on the back stroke
of the shaping machine I squared out the two corners D x %2 in.
wide. I then changed the bar to the other hole and repeated the
operation on the corners E. I then turned the bar 180 deg. and
cut the wall between the holes half-way through, then placed the
bar back in the other hole and removed the remaining wall.
This gave me a roughly squared hole ^%2 x 3 %2 in. I then
made up bars F and G which employed the same principle as
bar B. I roughed out the short size of the hole with the bar F,
turning the bar 180 deg. several times so as to gradually correct
what wave there might be in the length of the hole until the hole
measured 0.490 in.
I then used bar G, and sized the opposite sides of the hole until
it was within 0.0100 in. of size. Then changing to the bar F
I finished the hole to 0.50 in., and then changed once more to
bar G, and finished to 1.00 in.
It was necessary to make about four tools for each bar, and
though this process might seem somewhat elaborate to some, it
allowed me to accomplish results with the means I had at hand.
ADJUSTABLE EXTENSION PLANING TOOL
Fig. 112 shows an extension planing tool that is now being
used in a large munition factory with considerable satis-
faction. This tool can be used on short and long strokes, and
may be of such length as the extension bar will permit. The
FIG. 112 ADJUSTABLE EXTENSION PLANING TOOL
144 AMERICAN MACHINIST SHOP NOTE BOOK
holder A is secured in the tool block, which is immovably clamped
in the clapper box. The extension bar B can be extended to
meet the requirements of the work, and can be turned to plane
at any desired angle, thus making it possible to plane a keyway
in any location in the hole without disturbing the work after it
is set up. The extension bar is tightly clamped by the gib C
and setscrews. The tool E is held in position in the tool block F
by setscrew D. The tool block swings on a taper pin G; a spring
H, held in position by a headless setscrew, keeping the tool block
down ; while on the return stroke the tool is free to lift by over-
coming the tension of the spring. The setscrew D is in an open-
ing, which permits it to lift the tool block and also to receive a
socket wrench for adjusting the tool. To obtain the best results
and maximum rigidity from the extension tool, and its holding
parts, they should all be case-hardened and ground. A neat fit
is essential at all points.
A TOOL FOR INTERNAL PLANING
The internal-planing tool shown in Fig. 113 has several
good features. It is ready for instant use in any planing or
shaping machine and is held in ^he toolpost in the usual way.
As the cutting tool lifts in the small clapper box at the end of
the bar, the shank can and should be blocked at its upper end,
making it very rigid. By turning the bar to the proper position
the piece to be machined can be planed on the top$ bottom or
either side at one setting. The tool being of the toolholder type
any shape of tool desired can be inserted.
If desired the bar can be made adjustable for length by thread-
ing and screwing it through the shank, as the clamping screw
will hold the threaded bar as well or better than the plain bar,
and no lock nut or collar is necessary.
The miniature clapper box on the end of the bar is pivoted
upon the taper pin, and while firmly supported against the
pressure of the cut is free to lift slightly on the return stroke.
To prevent chattering and jumping due to its lightness the upper
end, opposite the cutting point, rests upon a spring-actuated
plunger set longitudinally in the bar at the point indicated
in the illustration. The illustration does not of course show this
plunger and spring, but. as its function is to steady the clapper
PLANER AND SHAPER
145
on the return stroke its location and construction are ob-
vious.
FIG. 113 INTERNAL PLANING TOOL
RADIUS PLANING TOOL
Fig. 114 shows a tool I have used for planing small
radii. No clapper box is needed, as the cutter is placed just in
front of the shank and thrust collar. A hole through the shank
near the lower end receives the tool bar, the shank being split
for some distance past the hole to allow for clamping the bar by
means of the capscrew shown. A setscrew and hardened rod in-
serted from the rear end of the bar clamps the tool, which can be
set to any desired radius by measuring over the bar with a
micrometer.
Two holes are drilled at right angles through the outer end of
the bar to allow for turning it with a lever. To turn a radius,
the tension upon the bar should be so adjusted by the capscrew
that the tool will not move of itself under pressure of the cut,
but not tight enough to prevent it from being turned by means
146 AMERICAN MACHINIST SHOP NOTE BOOK
of the pin. Very accurate and perfect work can be done with
this tool, and there will be none of the chatter and trouble that
usually accompanies the use of formed cutters for the purpose.
FIG. 114 RADIUS PLANING TOOL
A REPAIR KINK ON A PLANING MACHINE
Some time ago the cross-rail of our planing machine being
badly in need of repair, and there being no other planing ma-
chine in the shop, we devised the following scheme for re-
dressing it:
The cross-rail was removed from its normal position and set
up on the table of the planing machine. A heavy plank was
bolted to the housings where the cross-rail should be, and the
head of a 25-in. Steptoe shaping machine firmly fastened to the
plank.
By taking advantage of the swiveling feature we were able to
run a cut in any required direction, and in the course of a short
time the planing machine was in service again with a practically
new cross-rail. The job can also be done by securing the worn
PLANER AND SHAPER
147
cross-rail to the floor, bolting an angle plate to the end of the
table of the planer and securing the shaper head to the angle
plate. This transforms the planer into a shaper. Much work
that is too large to pass between the housings can be shaped in
this way by mounting the cross-rail of the planer on angles se-
cured to the end of the planer table, and securing the work to
the floor.
DEVICE FOR HOLDING LARGE JOB ON SHAPING
MACHINE
Here is a kink for holding a large job on the shaping machine.
I had a large forming die to plane and could figure out no way
to hold it, as it was 16 in. wider than the machine table and at
no point did it come in line with the table slots. It was neces-
sary to machine the whole surface in one setting, so I devised
this rig.
FIG. 115 THE HOLDING DEVICE
In Fig. 115, A are two pieces bolted to the table, each hav-
ing four setscrews set at an angle, thus enabling me to get a firm
hold on the work.
148 AMERICAN MACHINIST SHOP NOTE BOOK
The outfit looks simple, but I find it a very handy means of
accomplishing work that without something of the kind would
be impossible.
CUTTING A NARROW SLOT WITH THE SHAPING
MACHINE
Having a number of pieces to make like A in Fig. 116, I was
confronted with the difficulty of cutting the slot which by reason
of its great depth in relation to its width, and also of the limited
amount of space available for chip clearance, presented an un-
usual problem.
FIG. 116 METHOD OF CUTTING A DEEP NARROW SLOT
The manner in which the work was done is as follows: The
tool was a section of heavy hacksaw blade fastened in a holder of
1-in. by IM-in. cold-rolled steel, and the work was held in the
split collar shown at B, which was in turn held in the shaping-
machine vise.
The toolholder was blocked at the upper end to prevent it from
lifting, and the cutting was done on the return stroke.
A slow speed was found desirable and close adjustment of
the ram was necessary, but after getting started a substantial
feed could be used, as each tooth of the saw did its own minute
portion of the work and the chips were all pulled out clear of
the piece, thus avoiding clogging and breaking the tool.
PLANER AND SHAPER
149
This method has proved so satisfactory that it has been ap-
plied to all work of this nature in the shop where I am employed.
SQUARING THE ENDS OF SMALL RECTANGULAR
PIECES
When squaring the ends of small rectangular pieces in the
shaper or miller, the piece may easily be set vertically in the
vise or chuck by the following method :
By laying a small pair of parallels across the vise jaws and
an adjustable square upon the parallels, as shown in Fig. 117,
: Top of Shapes V?se Jaws
FIG. 117 METHOD OF SETTING A PIECE SQUARE
the thumb of the right hand may be utilized for holding the
square firmly upon the parallels, while the index finger of the
same hand will hold the piece firmly against the square. The
left hand is then free to close the vise jaws upon the piece.
This scheme is much better than the plan generally pursued,
which is to allow the square to rest upon the bed of the vise, the
operator tapping the piece until it is set in the desired position.
Owing- to the absence of light between the vise jaws, the latter
method is not a sure one, and in addition too much time is con-
sumed if the piece being machined is small.
TURNING AND BORING . ATTACHMENT
There are many shops that are sometimes called on to do bor-
ing and turning jobs that are too large for the lathes at hand.
150 AMERICAN MACHINIST SHOP NOTE BOOK
Where there is not enough of this work to warrant the invest-
ment in a boring mill, the attachment shown in Fig. 118 will
be found very handy for these odd jobs.
This fixture is of simple construction, similar to circular mill-
ing attachments in general use. Part of the table shown at A
is a worm gear, driven by a worm on the end of the shaft B.
FIG. 118 A TURNING AND BORING ATTACHMENT FOB THE PLANER
This shaft is supported at the outer end by the bearing C,
which is bolted to the planer table. Power is obtained through
pulley D, which is driven from the lineshaft.
The planer shown in the illustration is also equipped with a
milling attachment which is manufactured by the Adams Co.,
of Dubuque, Iowa. The two attachments make the planer a
very useful tool for the small shop.
DIVIDING ON A LATHE OR SHAPER
As we have no miller or dividing head, when a job of circular
dividing comes along we can generally find among the change
gears of the lathes in the shop a gear that has the same number
of teeth or a multiple of the number of divisions required.
We then fit a mandrel to this gear and to the work to be
divided, place it on centers either in the lathe or shaper and
after fitting a suitable stop to go into the space between the
teeth on the gear are able to do a fair job. In an emergency
we have cut gears in this way in the shaper.
SECTION VIII
TOOL MAKING
AUXILIARY BUSHING PLATE IN TOOLWORK
As the method of locating holes in jig work by the auxiliary
bushing-plate method is practiced in very few shops, the major-
ity of toolmakers are not familiar with its advantages in certain
classes of jig and fixture work.
At the top in Fig. 119 are illustrated two of the most common
t}^pes of bushing plates. They are made of cold-rolled or ma-
chine steel of convenient size, either straight or offset, as the
nature of the work demands. A hole bored near one end holds
a hardened, ground and lapped bushing at right angles to the
under side of the plate. This bushing is pressed into place and
remains a permanent part of the plate. A set of slip bushings
is made to fit this bushing. As the auxiliary bushing plate is
used mostly for work with medium- and small-sized holes, the
permanent bushings A, if made l^-in. inside diameter, will take
care of any size hole 1 in. or less in diameter. At B are shown
hook pins against which the pins D in the knurled collar of the
slip bushings bear, thus preventing them from turning while in
use. A typical slip bushing is shown at E. One of the bushing
plates has a milled slot C, the purpose of which will be shown
later.
In central illustration, Fig. 119, is shown clearly how the
bushing plate is used for locating, drilling and reaming the
bushing holes in a skeleton drill jig for an automobile-frame as-
sembly. There were altogether 18 holes of %-in. diameter to be
drilled and reamed. The allowances for error for all center dis-
tances were plus or minus 0.0025 in. All the holes were laid out
approximately, and the jig A was clamped on the cast-iron plate
B by four U-clamps and kept clear of the plate B by four par-
allel blocks C to provide clearance for drills and reamers. The
size of the plate B is determined by the sizes of the jobs that it
151
FIG. 119 AUXILIARY BUSHING PLATE
152
TOOL MAKING 153
is to accommodate. The one shown is 2 l /2 x 30 x 40 in. ; it has
both sides planed parallel and the edges squared all around.
A number of holes are drilled and tapped for tap bolts for
holding the work and the bushing plate. The grooves D pro-
vide means for clamping the measuring block E to the edge of
the plate B.
The method of locating, drilling and reaming the holes is as
follows: The baseplate B, with the jig A, is laid on the
table of a radial drilling machine, and the first hole F is drilled
and reamed. The auxiliary bushing plate G is now set over the
location of the next hole, its under side elevated about ^ in.
above the jig and resting on parallel blocks H. In rapping the
bushing plate into position, a %-in. plug is placed in the reamed
hole F, and a 1%-in. ground plug in the hole / of the bushing
plate. Measuring from the block E and the plug in F, it is easy
to set the bushing plate G for the next hole. After the bushing
plate is set, the plug is removed and a suitable slip bushing in-
serted in the hole 7. The cycle of operations is just as it is in
any drilling and reaming through a bushing. For subsequent
holes the same procedure is repeated.
I should like to draw especial attention to the grooves D,
and the measuring block E, two of which were made, al-
though only one is used in connection with the job shown.
The measuring blocks were made of tool steel 1 x 2% x 7 in, ;
they were hardened and ground parallel on the 1-in. measure-
ment. By this method of taking measurements from the squared
edges of the baseplate, very accurate and quick settings of the
bushing plate can be obtained.
In the bottom illustration, Fig. 119, is shown another way of
using the auxiliary bushing plate. In this case the offset type
of bushing plate is used. The dimensions of a top plate for a
box jig are given. In this job six holes are called for, four of
%-in. diameter and two of 2-in. diameter. A job of this kind
could be done by the button method. No baseplate was used on
this job, and all drilling, boring and reaming were done on an
ordinary sliding-head drilling machine. The bushing plate is
held to the jig plate as shown. It might be well to mention that
the hole C is drilled and reamed first in the ordinary way ; for
the rest of the holes the bushing plate is used, which is located
accurately by means of a height gage and the surface plate. All
154 AMERICAN MACHINIST SHOP NOTE BOOK
four edges of the jig plate are carefully squared, thus eliminat-
ing all uncertainty in locating the bushing plate. All the holes
check up to within 0.001 in., which is 0.0005 in. closer than the
greatest allowable error.
An interesting feature about this job is the boring of the
two 2-in. holes. A 1-in. drill was used in the first place, then a
%-in. boring bar working through a %-in. slip bushing till the
hole had been enlarged to 1^ in., after which a 1-in. boring bar
and a 1-in. slip bushing were substituted and the hole bored to
its finish size. The space between the offset of the bushing plate
and the jig provides sufficient clearance for setting the boring
tool bit and for calipering. By the aid of the slot C, in the upper
illustration, the bushing plate can be secured to any position
over a jig plate of large dimensions, provided there is a hole for
the bolt.
AN ECONOMICAL COUNTERBORE
In these days of high-priced steel many ingenious ways have
been devised whereby the waste of the steel has been brought
down to a minimum. Fig. 120 shows a four-fluted coun-
terbore. The body is made of high-speed steel and the rest is
TOOL STL
(Hardened ana Ground)
c
D.'
FIG. 120 AN ECONOMICAL COUNTERBORE
made of carbon tool steel. When it is necessary to grind the
counterbore it is disassembled by unscrewing nut A, and pulling
out the lock washer C, when the body D can then be pressed off.
The body D should be a ring fit over spindle B. It can be seen
that as the counterbore is ground off the nut and lock washer
are brought closer to its end until there is hardly any of the
body left. Another good feature of this counterbore is the
movable pilot. The hole that this pilot was to run in was a very
TOOL MAKING
155
particular one, with only 0.001 in. limit. The ordinary pilot
would wear the hole large, but in this pilot there is no wear on
the hole in work.
BUTTONS FOR MEASURING ANGULAR WORK
Fig. 121 shows buttons that may be used in measuring
external and internal dovetails, table V's, triangular and irregu-
lar shaped pieces and similar work when it is impracticable and
in most cases impossible to measure over sharp edges.
FIG. 121 BUTTONS FOR ANGULAR WORK
The buttons are cylindrical plugs with cutaway sectors.
Angles of 60 deg. and 90 deg. will be found most useful, but
they may be made of any angle and of any size. These buttons
have a large field of usefulness in the toolroom, and considerably
shorten the time required to check some classes of angular work.
CARTRIDGE-PUNCH TEMPLET
A simple and accurate gage for testing the formed ends of
the punches is made as shown in Fig. 122.
A piece of sheet steel about No. 14 B. & S. gage is cut to size,
and the outline of the punch is scribed on it. The portion in-
side the lines is then cut out and the opening filed to size. In
use, the gage is placed over the end of the punch to be formed
and held to the light. If the punch has not been reduced
156 AMERICAN MACHINIST SHOP NOTE BOOK
enough, there will be a space between the end of the punch and
the bottom of the gage. The punch is reduced until it touches
the bottom of the gage, which should fit on without pressure.
A more accurate method of making the gage is shown.
A reamer is made, the cutting end having the same form as
the tapered end of the punch. A piece of sheet steel B is cut
FIG. 122 CARTRIDGE PUNCH TEMPLET
to a convenient size; one side is squared up, and a punch mark
D is made in the center of the side. It is then clamped between
two blocks of steel E and centered in a lathe chuck by means of
the punch mark. A hole is drilled and bored out to nearly the
finished size and finished with the reamer. The plate is then
taken out of the chuck, and the radius A is just filed out.
MAKING A CIRCULAR FORMING TOOL
A large number of circular forming tools as shown in Fig. 123,
which were required in turning the base ends of shrapnel fuse
bodies, called for accurate machining and with the exception of
the surface X, were to be ground all over. To get the blanks
ready for the forming operation was an easy proposition ; how-
ever, the method of putting on the form may be interesting.
A block B, having an opening Y, was placed on the toolpost
and rigidly clamped in position on the tool rest. This block
had two slots milled in it at proper points, in which were
located the cutting tools. Each of the cutting tools was pro-
TOOL MAKING
157
vided with a slot to receive a stud to which the cutting tool
was secured. Adjusting screws in the block were provided to
engage the outer ends of the cutting tools, and hold the latter
in position against rearward movement from the work. The
depth of the cuts on the blank, as well as their position, was
provided for by means of a guide piece F, which contacted with
the side of the blank, and also with the flange on the mandrel.
After the milling and hardening operations, the forming tools
were trued up on the internal grinding machine faceplate by
slipping them over a removable plug piloted in the hollow
FIG, 123 MAKING A CIRCULAR FORMING TOOL
spindle, clamped and then ground to size in the holes. The
end faces were then ground while on centers the larger surface
first, and then the smaller end on the surface grinding ma-
chine. The various surfaces that made up the form came next.
Probably the most common method of checking angular forms
is the use of a thin profile gage, trusting to the operator's sense
of sight, and his guessing ability as to where and how much stock
is to be removed.
The combined grinding mandrel and gage shown provided
means for measuring with a micrometer and overcame the ob-
jectionable feature of guesswork as in profile gaging. The
mandrel H was hardened and carefully ground all over. The
tapered portion I formed a continuation of the front conical
158 AMERICAN MACHINIST SHOP NOTE BOOK
section of the forming tools, with the diameter, before rounding
the same as on the finished tool. The circular forming tools
were slipped on the spindle J, of the mandrel bearing against
the portion / and held in place by the nut. As shown, the sur-
faces L, N, and were made parallel to directly opposing edges
of the three angular surfaces. The measurements were taken
from these parallel surfaces with micrometers.
The table of the universal grinding machine used was swung
to suit each angle so that the face of the wheel could be used.
Considerable time was saved by running through a large num-
ber at each setting, and with this method of checking, the pro-
duction was unusually high-class for this character of work.
CASEHARDENED JIG BUSHINGS
In my opinion there is no advantage in the tool-steel bush over
the casehardened bush, with regard to wearing properties. As
the case is generally not less than 0.006 in. thick, the bush is
scrapped for inaccuracy long before the softer core is reached.
The casehardened bush has the further advantage that, when
forced into the body of the jig, the compression will be largely
taken up by the soft core and very little of it communicated to
the hardened case surrounding the bore of the bush. There is
thus less likelihood of cracking the bushes, should the forcing
allowance by any chance be big.
ADDING LIFE BY TAKING CARE OF A MICROMETER
For accurate work, the measuring faces of a micrometer
should be perfectly parallel. To true up the anvil and the end
of the spindle, I have made the device shown in Fig. 124. To
Method of Usi
Method of Using Device
for Micrometer Spindle
Device for Lopp.ng
Micrometer Spindles
FIG. 124 METHOD OF TRUING A MICROMETER
TOOL MAKING 159
use this, proceed as follows. Remove the spindle from the mi-
crometer and insert it in the holder A, as shown. It is un-
necessary to tighten the setscrew B for this operation. A little
rubbing on a cast-iron lap plate will true up the end of the
spindle. Now remove the spindle from the holder and, after
cleaning thoroughly, replace it in the micrometer. Then put the
holder A in position, as shown to the right. Tighten the screw B,
The lap C is placed in position and the micrometer spindle ad-
justed so that 'it will just slide between the holder A and the
anvil. The side next the anvil is of course charged with an
abrasive. By rubbing C back and forth, the anvil is lapped true
with the spindle. The lap C is about 2& in. long.
GRINDING PRECISION TOOLS
Many flat gages are now employed that invariably have to be
scraped to precision before hardening, as there is no other avail-
able way that is profitable. This necessitates a scraping tool
ground to required accuracy, even though the gages are ground
and lapped.
Precision tools in reality are gages themselves, and require the
skill of a gagemaker to produce an accurate job. Fig. 125 shows
a gage which requires a form-tool composed of a series of very
minute angles, and by no means a job for an unskilled mechanic.
These angles being difficult to measure and there existing various
ways they could be measured, some doubt arose as to which
method would obtain the most accurate results. The following
was adopted: Angle A was figured out trigonometrically.
The protractor was set at proper angle, and the length of
angle then obtained by means of size blocks 0.043 in. thick.
Care should be taken to have point of blade sharp, that when
under the magnifying glass the point will determine the ex-
tremity of angle. The 45-deg. angle was ground by originating
an angle on the wheel and thus obtaining the sharp corner de-
sired. From the side of the tool, angle A, to the beginning of
the 45-deg. angle is 0.093 in. Now, setting small adjustable
square 0.093 in. with size block and again using glass, grind
45-deg. angle until it comes even with point of blade. Care
should be taken to have end of blade perfectly square and cor-
ners sharp. Depth 0.038 in. can be measured with depth gage.
160 AMERICAN MACHINIST SHOP NOTE BOOK
Precision tools necessarily have to be backed off, and many
times this is accomplished by two different settings, which is
unnecessary. The writer's method, and perhaps one used else-
where, is by means of square block attached to an angle iron as
shown. By such means the double angle can be obtained, elimi-
nating resetting for backing off.
FORM TOG~
J
**
<-'O.4l5*>
\
:
i
^ , *
i
i
*+\
<\
!T
IV*
T
i 4
1
/
^
?
i
< ^s .
11
n
k--
r i
u- *...
V
.1
FIG. 125 METHOD OF OBTAINING GAGE ANGLES
The block is hardened and ground perfectly square all over,
and is found useful on many other jobs besides precision tools.
LOCATING HOLES ON CLOSE CENTERS BY
MEANS OF SPECIAL BUTTONS
Fig. 126 shows a part of a drilling fixture in which three
holes were to be located too close together to allow the use
TOOL MAKING
161
of a test indicator. The first time the job came up the holes
were located and drilled one at a time, but this method con-
sumed more time than was necessary and allowed greater oppor-
tunity for error than if all the buttons were located at one set-
ting.
FIG. 126 LOCATING CLOSE CENTERS WITH SPECIAL BUTTONS
The second time the job was to be done, the writer was pre-
pared with special buttons, one longer and one shorter than the
regular set. This allowed all three buttons to be set at once, and
by swinging up the longer one first the lathe man was enabled to
center and bore them in succession.
A THREAD-GRINDING FIXTURE
Fig. 127 shows a fixture for grinding threads that can
be used on the compound rest of any lathe. The body A of the
fixture has a rib planed to fit the toolpost slot, and is provided
with a collar-head bolt and square nut for clamping the fixture
in position. The bracket B carrying the wheel spindle swivels
162
TOOL MAKING 163
upon part A, the axis of the swivel being horizontal at right
angles to the center line of the wheel spindle and opposite to the
vertical center line of the wheel.
Means are provided for swiveling this bracket and for clamp-
ing it in whatever position may be necessary to make the plane
of the wheel conform to the angle of the thread being ground;
and as the axis upon which this movement takes place is coin-
cident with the center of the wheel it follows that this adjust-
ment does not affect the relative center positions of the wheel
and the work to be ground.
One edge C of the swiveling bracket is finished and graduated
so that the thread angle being known, it is but the work of a
moment to tilt the wheel to a corresponding angle.
The bracket B has an extension D parallel to the vertical
plane of the wheel, this extension carrying a slide E which is
adjusted vertically by means of the screw F. Upon the face of
this slide are mounted two smaller slides G and H with their
lines of travel 30 deg. either side of the line of travel of the slide
upon which they are mounted. These smaller slides are ar-
ranged to carry diamond toolholders directly over the center of
the grinding wheel. They take their movement from the com-
pound lever /, which causes first one diamond and then the
other to pass over the angular surface of the wheel, dressing it
whenever this is necessary.
As the part upon which the slide is mounted is integral with
the wheel-carrying bracket, swiveling the latter about its axis
does not affect the positions of the diamonds in relation to the
wheel; therefore when once set the tools are always in position
for truing the wheel.
The wheel spindle runs in tapered split-shell bearings provid-
ing ready means of adjustment to compensate for wear.
MAKING A HEIGHT GAGE OUT OP A VERNIER
CALIBER
At the present time it is practically impossible to buy vernier
height gages owing to the unprecedented demand for them, and
the necessity of waiting, sometimes for long periods, for an op-
portunity to use the gage owned by the shop led me to use this
otherwise unprofitable time in making an attachment for my
164 AMERICAN MACHINIST SHOP NOTE BOOK
6-in. vernier caliper which would transform it into a height gage
without interfering with its other sphere of usefulness.
Many toolmakers who do not possess a height gage own a
6-in. vernier caliper, and the few simple accessories shown in Fig.
128 will make of it a convertible tool that will perform the
duties of either.
FIG. 128- -CONVERTIBLE VERNIER HEIGHT GAGE ^> ND CALIPER
I have my vernier caliper so equipped, and woi ild not now ex-
change it for the regular tool, as its accuracy cculd not be sur-
passed by the latter and it is more convenient and adaptable.
The base, show a at A in the assembled tool and at B in a re-
versed position, if made of tool steel, the small holes indicated by
the arrows being drilled clear through to facilitate grinding the
bottom of the slot. The pocket on the underside serves to
lighten the tool and to provide a recess for the nut which holds
the parts together. The slotted stud C and its nut D are made
of cold-rolled steel and should be casehardened to resist wear.
The stud is a slip fit in the hole through the base, and the slot
in the stud is made just large enough to allow the fixed jaw of
the caliper to be easily set in place.
TOOL MAKING
165
The slot in the base is of course accurately ground to fit the
fixed jaw of the caliper, which should also have a light cut taken
over the back to insure accuracy. The base should be ground on
the bottom after assembling, the manner of holding the tool for
these operations being shown at E,
A few passes over a good lapping block to remove the wheel
marks will finish the base.
The scriber clamp shown at F, which can also be used to at-
tach an indicator, is too familiar to need description.
A RADIUS TRUING FIXTURE FOR USE ON
GRINDING WHEELS
It is essential on various classes of tool and die work that the
radii be ground, therefore a radius truing fixture must be made
to suit the purpose. There are many types of fixture in use in
various parts of the country, some of which are simple and
others complicated.
FIG. 129 FIXTURE FOR TURNING RADII ON GRINDING WHEELS
Fig. 129 shows a successful fixture, which is very simple
in construction and less costly than some I have seen.. It is
quite rigid, which is essential to success in making a true
radius, and is very easily adjusted for both internal and external
radii. The diamond is set by means of size blocks by which
method an accurate setting may be attained. All parts of
166 AMERICAN MACHINIST SHOP NOTE BOOK
machine are casehardened, thus assuring accuracy of fitting and
better wearing surfaces.
The base A is surface ground on the top and bottom, and the
hole is ground to 1.500 in. diameter. On the plate B the
0.500-in. diameter hole, the 1.500-in. diameter projection and the
surface that bears on the base A should be ground in one set-
ting to insure precision.
The T-slot is ground to 0.500 in. in width, making it easy to
center it with the 0.500-in. hole for the setting plug C. The
shank of the plug C is ground to fit the 0.500-in. hole, while the
body is ground to 0.600 in. in diameter. For about l 1 /^ in. of its
length one-half its diameter, or 0.300 in., is ground away, leav-
ing a flat that exactly cuts the center line, and it is from this
flat that all settings are made. A small projection about %6 in.
in length and of suitable diameter is turned on the end of the
plug to facilitate grinding, and should be eliminated after finish-
ing. The diamond holder D is adjustable in the T-slot, and the
shank of the diamond is also adjustable in the holder, thus al-
lowing a wide range of adjustment.
The section E is for setting the diamond for truing internal
radii and is also adjustable in the T-slot. By means of the size
blocks the setting point F is adjusted to the correct distance
from the center, the center plug being turned around if the de-
sired radius is less than 0.300 in. The center plug is then re-
moved and the diamond adjusted to contact with the face F, the
section E then being removed from the fixture.
In making small internal radii on grinding wheels a small
diamond especially adapted for this purpose is necessary and a
radius smaller than 0.125 in. is impracticable. This fixture will
accommodate wheels from 3 to 7 in., in diameter, which is the
range ordinarily used on a Brown & Sharpe surface-grinding
machine.
ACCURATE SETTING DEVICE FOR INTERNAL
GRINDING
We do a great deal of internal grinding of small holes (%2 to
% in. in diameter) in perforating dies. The perforating die-
holes have a taper of 0.004 in. in 1 in., and the dowel Iroles are
perfectly straight. The dies are mounted on master plates,
TOOL MAKING
167
therefore all the holes in each die must be ground before the die
on the master plate is disturbed, which means that the grinder
must be set to grind 0.004 in. taper and also to grind perfectly
straight on each die.
Not being able to depend on the graduations on the grinder for
extreme accuracy, it was a case of more or less cut and try, and
this consumed a great deal of time.
In order to reduce the time of setting the machine and to ob-
tain a greater degree of accuracy, I made the attachment shown
in Fig. 130. This device made it possible to set a machine in a
FIG. 130 THE SETTING DEVICE
very few minutes so that it would grind a perfectly straight hole
or an accurately tapered hole without the usual experiment-
ing.
A is the head on the internal grinder; B is an adjustable
straight-edge %6 x % x 7 in. graduated in half inches, swiveled
on a %6 in. pin at C and slotted to allow adjustment on the
%6-in. clamp screws at DD. The dial indicator E is mounted
on the bracket, which is attached to the bed of the machine.
To set the straight-edge, chuck a piece of about %-in. steel ex-
tending say 2& in. from the chuck, then external grind, setting
the swivel table so that the machine is grinding parallel. Now
set the straight-edge A so that the indicator shows it to be par-
allel with the travel of the table. After the straight-edge is set
and clamped in this position, use the indicator to set the ma-
168 AMERICAN MACHINIST SHOP NOTE BOOK
chine. Straight or tapered holes can then be ground with ex-
treme accuracy.
TRANSFER GAGE FOR PIERCING DIES
Many times in making piercing dies with small holes it is nec-
essary to use a very small drill and drill back from the bottom
side with a larger drill in order to enter the taper reamer for
making the clearance. On a thick die, if the small drill is run
clear through to locate the larger drill on the other side, the
small drill breaks easily and causes a lot of bother and loss of
time in annealing and remarking the die. I have never seen
any tool advertised to transfer the holes, but I have found that
the transfer gage shown in Fig. 131 works very well in such
cases.
FIG. 131 THE TRANSFER GAGE
I have one of these which I made and have used for some time
and I find that it is a very handy tool. To use it it is only neces-
sary to run the small drill part way through, then put the die
between the two plates of the gage and hold it so the drill hole
lines up with one of the holes in the gage. Turn it over and
mark the hole on the other side with a scriber to get the center
for the larger hole. In this way a great deal of time and drill
breakage is saved. The gage should be made of tool steel hard-
ened to resist wear, but can be made of machine steel casehard-
ened.
USEFUL ANGLE PLATE
Nearly every toolmaker carries a small angle iron in his kit.
It is generally too small for most jobs, but, of course, it is made
small, with the idea that it must fit into a certain space in the.
TOOL MAKING
169
owner's tool chest. In a great many shops, it is hard to find an
accurate angle plate for tool or gage work, so I made one, shown
in Fig. 132. It is not too large to go into my chest, and yet it is
large enough to use in combination with a 5-in. sine bar.
FIG. 132 THE ANGLE PLATE
It is made of cast iron and planed and hand scraped so that
it is dead square every way. The 90-deg. V-slot in the top adds
greatly to its usefulness. It is handy around the surface grind-
ing machines. In fact, on a great deal of accurate grinding
work I would hardly know how to get along without it. All
finished surfaces are provided with }4-in. 20-thread tapped holes
at intervals of % in. to facilitate the clamping of work.
I notice that a good many toolmakers have angle plates made
of steel, hardened and ground, but I prefer cast iron, as I find
that a well-seasoned casting does not change shape so readily as
the majority of grades o hardened steeJ A I have two other
170 AMERICAN MACHINIST SHOP NOTE BOOK
angle plates besides the one shown here, one being made of cast
iron and the other of hardened steel. My experience has led me
to prefer cast iron, not only because it is easier to work in the
first place and retains its accuracy to a greater degree, but be-
cause in case of necessity it is easier to correct by hand scraping.
SECTION IX
DIE AND PRESS WORK
SHEET-METAL WORK
AT the present time when sheet-metal production is being
made to fit all kinds of stamping and drawing operations, it is
advisable to use this metal in many cases where castings and
drop-forgings are used, and by making good tools tools that
are designed properly to produce accurate and finished pieces
the factory cost of production can be cut appreciably.
We all know that patterns and castings are necessary in many
cases, but there are cases where tools can be employed to pro-
duce punchings that will fit in and do the work of castings with
a much lower factory cost. The snagging, drilling, planing and
milling of the castings is thus done away with by die-blanking,
drawing, forming and piercing operations of the tools done on
the one press and by the same operator, thus saving the moving
of parts from one machine to another.
In using sheet steel it is essential to have the bends and breaks
made across and not with the grain of the metal. However, this
is not taken into consideration with deep stamping and forming
steel, as this steel is dead soft and can be put in the die with any
angle of the grain. Still on hot-rolled steel and hard sheet steel
the practice mentioned is essential. Bending with the grain on
hard steel is liable to make cracks and splits.
Some manufacturers in their specifications will state that
certain steel will bend at right angles across the grain; other
steel (softer) will bend flat on itself across the grain, but only
at right angles with the grain. When making bends with the
grain, and not being familiar with the steel, a rounding bend is
safer than a sharp bend.
A good feature of cold-rolled steel is the very smooth surface
that can be obtained. Invariably pieces that are made from
very smooth steel do not need any grinding to fit them for the
171
172 AMERICAN MACHINIST SHOP NOTE BOOK
plating bath, but a buffing- or soft-wheel operation is all that is
required. This steel costs more to buy, but if these grinding
operations are eliminated, then it is cheaper in the end to use a
high-grade, smooth-surface steel.
Another thing to be reckoned with is the scarcity of copper
and brass. Years ago sheet-metal articles were made of copper
and brass for the reason that sheet steel would not do the work.
Today, however, sheet steel can be obtained in almost any de-
gree of softness, and this is largely taking the place of sheet
brass and copper.
"We have had complaints that steel would never fill the place
of brass and copper, as the rust made it unfit for ornamental
articles; even if nickeled it was not satisfactory, as when used
in damp places the rust would work through the nickel plate
and finally become very unsightly. To the manufacturer this
need not be cause for worry, for if the steel parts are given a
copper plating first, and then a nickel plating, the rust will never
come through. Copper has better affinity for steel, or seems to
hold better in solution than nickel. On the other hand, nickel
will hold well on copper. Therefore, if the steel parts are
given a copper-cyanide bath first, the nickel will hold and rust-
ing will be overcome.
Castings that are used for heavy duty can be supplanted by
steel stamping in some cases. We have used boiler plate for
this work, and by heating it red hot it can be formed and drawn
satisfactorily. Of course, this is for work where surface ap-
pearance does not count and where grinding and polishing are
not necessary.
For marine work, steel fittings and punchings may be used
satisfactorily, and if the parts are sherardized there is no
chance of their rusting. It is the duty of every manufacturer
to use steel wherever possible, and steel can easily be substituted
for the more expensive materials, copper and brass.
Lastly, when using sheet metal, make stock layouts of the
parts to be punched and determine the proper width before or-
dering. Then there will be a minimum of waste. Also by or-
dering multiples of the blank required, short ends are eliminated.
Some blanks can be nested one with the other to save scrap. The
writer has in mind a job in which by staggering the blanks the
saving in scrap was nearly 30 per cent, over the old method.
DIE AND PRESS WORK 173
LOCATING SMALL HOLES ACCURATELY IN DIE
WORK
One of the difficult problems for the diemaker to solve is that
of accurately locating holes of very small diameter, such as are
often met with in small die work in model making. It fre-
quently happens that several holes have to be located in a pro-
gressive or a piercing die. If the centej 1 distances of these holes
may vary only 0.001 in. or less, it looks quite a problem some-
times, and more especially when the button method is out of the
question on account of the button screw being larger than the
diameter of the holes to be bored.
By the method here described, it is possible to locate such
holes very accurately and also more quickly than by any other
way that I have tried for this class of work, except, of course,
with a special vernier-equipped die-boring machine. A good
illustration of the principles involved can be had by following
the various stages in the making of the progressive die blank for
a clock-mechanism part, Fig. 133.
From this sketch it can be seen that a tolerance of only
0.0005 in. either way is allowed for the center distances of all
three holes. The circular rack A is rough blanked in the same
die, sufficient stock being left for a finish-shaving operation in
another die.
The layout of the first die is given in the lower sketch. The
blank, which is of No. 19 gage (0.0437-in.) cold-rolled steel, does
not have to be held to close limits, with the exception of the cir-
cular back part. As this is finished in a later operation, spacing
the three holes with sufficient accuracy comprises the real prob-
lem in this case.
The die opening A is worked out to a model, and the
%6-in. holes B, C are bored part way through the die blank, the
clearance holes being large enough for the full passage of slugs.
Two pieces of drill rod /i'e in. in diameter by VI'G in. long are
next driven into these holes, and two %-in. holes are drilled and
reamed halfway into the die blank and the drill-rod plugs, as at
F. The plugs are next removed, and the die blank, with the
finished die opening A, is hardened. After hardening, this die
opening is honed and retouched to fit the model. The drill-rod
plugs, together with %-in. dowel pins in holes F y are driven in.
FIG. 133 LOCATING SMALL HOLES ACCUEATELY
174
DIE AND PRESS WORK 175
and the die blank is ground parallel on both faces. Also, the
edges G and H are ground square, the edge H being parallel to
the center line of the three holes. Grinding the edges G and H
facilitates locating the button and the drill plate while the die
blank is resting on those edges on the surface plate, as will be
shown later.
Next the plug in the hole C is drilled and tapped for the
button screw, and the button is set to the correct location by the
usual method, using an indicator in the height gage and taking
the necessary measurements from points of the finished die
opening. The button thus secured is trued up, and the 0.2197-
in. hole is bored out in the lathe. For the two 0.051-in. diameter
holes the following method is employed : A piece of We-in. flat
cold-rolled steel is drilled so that a 0.051-in. rod is a good sliding
fit in the hole, after which the cold-rolled steel plate is cyanided.
The upper figure shows the successive steps in locating and
drilling the two 0.051-in. holes in the inserted drill-rod plug in
the die blank. With a 0.051-in. plug A, in the drilled hole of the
cyanided plate B, and a plug 0, consisting of two diameters
.namely, 0.2107 in. and 0.051 in. concentric with each other (a
good fit in the previously bored hole of the die), locating the
plug A correctly for one of the small holes is but a matter of
measuring with micrometers and the height gage from plug to
plug, testing with the height gage as shown.
After the plug A with the plate B has been tapped into place,
the plug A is removed and the die blank, with the drill plate
held securely with clamps, is taken to a drilling machine. At E,
is shown the die blank resting on parallels on the table of
the drilling machine, preparatory to drilling the 0.051-in. hole.
It might be said that the hole is first spotted through the drill
plate with a 0.051-in. drill, then drilled right through with a
drill a few thousandths less in diameter and finally reamed with
a 0.051-in. twist drill, which has the corners rounded so as to
produce a smooth hole. The drill plate is next removed and the
remaining hole treated identically.
All three holes are now taper reamed from the back for clear-
ance ; both Vik-'m. drill-rod plugs are removed from the die blank
and hardened, after which they are again pressed back in their
respective holes, the %-in. dowels lining them up to positions
they occupied while being drilled and bored. A slight finishing
176 AMERICAN MACHINIST SHOP NOTE BOOK
cut is taken over the die face in the surface grinder, thus com-
pleting the die blank. The punch holder plate for this die is
drilled by the same method; and the blanks, when they come
from this punch and die, are well within the limits specified.
In cases where one of these drill plates is to be used frequently,
it is a good policy to make them out of hardened tool steel; a
piece of ground tool-steel stock does nicely for this purpose.
The method just described is a very valuable one in shops
where the equipment is not of the best, but where the quality
of work turned out is expected to be first class. When the die-
maker knows all these " tricks of the trade," he need not get
discouraged when confroi/ted with a job of this description.
ARRANGEMENT FOR A LARGE COMBINATION
DIE
This is one of the larger combination dies where the blank
can not be dropped through the bolster, but has to be pushed
out of the die by placing springs or rubber between the stripper
and bolster. The placing of springs or rubber bumper on the
bottom of the bolster is not always possible. To set a die of
this kind the stripper plate is screwed down to let the punch
enter the die while setting. To remove these screws is an awk-
ward job for the die setter on account of the limited space be-
tween the punch and die.
FIG. 134 A COMBINATION DIE
In Fig. 134 a stripping arrangement is shown that can
be taken out of the die before setting, and simply dropped in the
die after setting. Between the stripper plate A and screwheads
C the washers D that are larger than the screwheads and the
springs E are placed. When the punch forces the blank down
with the stripper the compression of the springs is taken up be-
DIE AND PRESS WORK
177
tween the stripper plate A, and the washers D, resting on shoul-
ders of the bolster shown at F. Normally the force of the partly
compressed spring is taken up between the screw heads and strip-
per plate or the thread of the screws. A good way to dispose of
the slugs from small piercing punches is shown in the drawing.
After the slugs have been pushed through the blank by the
piercing punches G, they enter the holes H and follow the paths
shown by the arrows being dropped back on the blank or on the
outside at 7.
A WIRE BENDING DIE
Referring to Fig. 135 the wire is pushed through the
cutting block A to the stop B. The press is tripped; the cam
FIG. 135 WIRE BENDING DIE
punch K is entered between the rolls in the slide 0, which moves
forward cutting off the wire. C now remains stationary while
178 AMERICAN MACHINIST SHOP NOTE BOOK
the bending slide J> is moved forward by the cam punch L to
the stationary punch E, forming the wire in the shape shown at
Z. (In this bend the wire slides on the gage blocks F, which pre-
vents the wire from getting under the corner of the bending
punch E lettered EL)
The slide D now becomes stationary by reason of the roll in D
riding on the straight part of the cam L lettered LI. At this in-
stant the punches G engage the wire at X, completing the bend-
ing operation. The chisel cutters H of which there are two,
one in the stationary punch E, and one in the slide D, have sev-
ered the wire at Y with an angle point (for driving into wood)
at the finish of the stroko of the slide D. This slide D is re-
turned to its starting position by means of a spring in the die
shoe. The stripper 7, which is under the spring tension, ejects
the wire from the shelf on slide D, allowing the wire to fall
through the slot J in the die shoe into the separate boxes under
the press.
PROGRESSIVE DIE FOR RUBBER WASHERS
The design of a die for punching hard-rubber washers illus-
trated in Fig. 136 embodies some interesting and novel features
of construction. The die as it appears when assembled is shown
and it can be seen that it is of the progressive type, or as it is
sometimes called a "follow" die. The die shoe A, of cast iron,
has the plate B mounted on it and held with seven fillister-head
screws. The cutters are mounted on the die shoe, the punch
proper consisting of five blocks of hard maple glued together,
and held with screws to the cast-iron punch-holder. The con-
struction of this being so simple that no further explanation is
necessary. Hard rubber was the material worked on and it came
in strips 3 in. wide.
The operation of the die is as follows : The stock is placed on
the stripper plate, over the first punch C, and held against
the stock guide. The punch block on descending, forces the
rubber strip and the stripper plate down over the cutters till
the sharp edge F has cut clear through the rubber and slightly
into the hard maple block of the punch. On the upstroke of the
press the stock is stripped by the aid of the six springs, and be-
ing moved further over, the stripper plate is located over the
DIE AND PRESS WORK
179
next position by the pilot G entering the 1-in. hole pierced by
punch C. In this position the six %-in. holes are pierced, while
with the same stroke of the press another 1-in. hole is added,
which in turn is located over the pilot G, and the punch block
on descending cuts out the finished washer by forcing it through
the hollow punch /. Now a complete washer will drop through
the opening J of the die shoe.
The section gives a few more important dimensions of a cutting
FIG. 136 RUBBER WASHER AND DIE WHICH PRODUCED IT
die, all of which were made of a good grade of tool steel, hardened
and drawn to dark straw on the cutting edge, and made similar
in proportion. It will be noted that the cutting angle is 30
deg., which was found to give entire satisfaction in hard rubber.
The shoulder accommodates the bushing P, shown in dotted
lines, which is for the purpose of pressing the cutters out of the
punch plate, when the cutting edges need regrinding. Three of
these bushings were made, one for each different size of punch,
180 AMERICAN MACHINIST SHOP NOTE BOOK
The diameter of these bushings is a few thousandths less than
the hole for the corresponding punch in the punch plate.
In all rubber-washer punching, but especially for those of
larger size, a progressive die made as the one just described, is
much easier to make, and of longer life than a complicated com-
pound die. It is also easily set up and operated in the punch
press. When the punches become dull, they can be reground,
and put back in a short time.
Care should be taken to have the bottom faces of the small
cutters marked with a corresponding figure on the plate in
order that each cutter may be put back in its proper place after
grinding. Of course, this would not be necessary if all the cut-
ters were made interchangeable as regards the outside diameter
and depth of shoulder R, but this would hardly be practicable
on account of the extra time needed to accomplish this result.
PRODUCING A BULGE IN TUBING
Soft-lead slugs can be inside tubing to do the bulging after
which they can be melted out but much time, cost and labor can
be saved by the use of cushion rubber slugs in the place of the
lead slugs, and the rubber slugs can be used over and over again.
After the pressure is relieved the rubber will return to its orig-
inal shape and drop out of the tubing with little or no trouble,
and may be used for the next piece.
I hardly think it necessary to use lead slugs, especially for
soft copper tubing, as I have formed many shapes from brass,
tin and light steel with a rubber punch.
In Fig. 137 is shown a common little shape that I have
manufactured by the thousands, with a rubber punch one piece
of rubber serving for many hundred pieces. At A is shown the
shell which is to be bulged. The die B is a block of steel slightly
hollowed as at C, to receive the bottom of the bulge. The punch
D is of hardened steel, close fitting, with the rubber pad screwed
to its bottom. The size and amount of the bulge is determined
by the adjustment of the stroke of the press. In the first opera-
tion the shell is drawn up on a No. 1^, toggle-action Bliss draw
press, with the common blank-and-draw push-through type of
dies, and the bulging operation is done on a 2-in. stroke Bliss
No. 21,
DIE AND PRESS WORK
181
The rubber pad on the bottom of the punch has a fillister-
head machine screw F in its upper end to engage a threaded
opening in the bottom of the punch. At G is shown a shell I
produced in this manner, which has a slight bead running
FIG. 137 METHOD OF BULGING SHELLS
around the center of the bulge. The complete shell was formed
from the original straight-side shell in one operation. While
the lead slug is practical, and will certainly do the trick, I think
the rubber slug will be just as effective at less cost and less labor.
MAKING PIERCING PUNCHES
The method of making punches and the jig here illustrated may
be of interest. In Fig. 138 is shown a finished piercing punch.
In making these punches, a piece of steel of the required length
is cut from the bar, heated on one end only, and then placed in
the opening A between the jaws B and C of the jig shown.
The jaw B is stationary and jaw C is moved about the pin
D by the eccentric pin and handle E. This movement is very
slight, being only enough to allow the punch to be easily
182 AMERICAN MACHINIST SHOP NOTE BOOK
dropped into place and clamped so as to hold it firmly while the
hot end is headed over.
The jaws B and C are lined with the steel blocks G, H and J.
These blocks may be replaced when worn, or others of a differ-
ent inside diameter may be inserted so that punches of different
sizes may be made in the same jig. After being headed, the
FIG. 138 THE PUNCH AND HEADING JIG
punch is chucked and the top of the head turned square with the
body of the punch. It is then chucked a second time and filed
for clearance at X, after which it is hardened and tempered for
use. This jig has been found very satisfactory for this work
and has paid for itself many times over.
PIERCING OPPOSITE SIDES OF THIN SHELLS
Some time ago I had several thousand drawn shells of tin
which had to have two holes pierced opposite each other, and
having nothing but a common punch press to do it with I
rigged up the die shown in Fig. 139. In the cast-iron base A
is fitted a slide B in which is a recess machined to take the two
half-round dies C. The slide is supported upon the rods D,
which in turn rest upon a rubber bumper which is under sum*-
DIE AND PRESS WORK 183
cient tension to stand the piercing of the top hole. After that
was punched, the ram, descending farther, caused the punch
holder to force down the slide carrying the die until the other
hole was pierced, by the stationary punch located in the base.
FIG. 139 TOOLS FOB PIERCING A THIN SHEET METAL SHELL
This arrangement worked very satisfactorily and as fast as
could be expected. The punchings came out in the hole in the
center of the die and when the press was inclined to a suitable
angle they fell out.
PRESS KINK FOR BLANKING CLOTH OR OTHER
SOFT MATERIAL
If you have a plain blanking punch and die, made for blank-
ing sheet metal, and wish to use the die for blanking felt, cloth,
flannel or other soft material, you can do so by running the job
184 AMERICAN MACHINIST SHOP NOTE BOOK
with about 0.010 in. thick iron or tin under the cloth and next
to the die.
Cloth blanks made in this way are just as good as those made
from an expensive compound punch and die. Care should be
taken to first grind the punch and die and put them in first-
class condition. Also shear both materials to the same width,
so that the work may be handled rapidly by the operator.
The foregoing plan was tried with red felt VQ in. thick and the
blanks that resulted were clean cut. One job was a double-hole
washer, the other a round washer % in. in diameter with a %-in.
hole.
SPRING-FORMING DIE
Fig. 140 represents the cross-section of a die for per-
forming the last operation on the flat spring represented at X,
while Y shows the spring as it comes to the die. The operation
of this die is as follows: The work is placed on the lower part
FIG. 140 CEOSS SECTION OF SPRING FORMING DIE
of the die between small gage pins, which are not shown. The
press is tripped ; and as the upper part of the die descends, the
ends of the spring are turned up in a vertical position by the
L-shaped piece A forcing the steel down into the groove cut
DIE AND PRESS WORK 185
through the square plunger head B. As the upper half of the
die continues to descend, the plunger B is carried down against
the action of a coil spring within the barrel C. The square steel
plate D is threaded to fit the thread on C and is fastened to the
cast-iron base of the die. The plunger B is forced nearly down
to the top of the barrel C when the wedge engages the slide G,
which is forced toward the center of the die and thus starts to
form that end of the work around A. As the downward action
continues, the other wedge engages the slide K and thus folds
over the other end of the work.
While this part of the operation is being done, B is stationary
and A is being forced upward against two heavy coil springs,
only one of which is shown at P. These springs are located in
diagonally opposite corners of the rectangular upper end of the
steel part A. In the other two corners are hold-up bolts that
also act as guide pins. One of these is shown at Q. As the
head of the press ascends, the slides G and K are pulled back
against stops by the coil springs R, as shown. There are two
of these springs on each side, arranged in the form of a V, to
pull on each slide. Bolts pass through the holes M and N to
fasten the upper half of the die to the ram of the press.
SOME PRESS-TOOL POINTERS
I believe that there exists no greater diversity of opinion re-
garding the design of equipment than is to be found in shops
that operate presses. During my experience I have encountered
much equipment that was altogether too expensive, because it
was not designed with an idea of being universal and for that
reason was, to me, impractical.
It will be my object in the following to show what I believe to
be the best practice in blanking, drawing and double-action
equipment.
In Fig. 141 is shown a die for drawing shells, first operation.
The recess in the upper side is made to the proper size for the
blank. It need not be the full depth of the thickness of the
stock, but merely enough to catch and center it. Dimension A
is the length of the ironing surface. This will differ somewhat,
according to the thickness of the stofk, but need never be over
% in. for stock up to %& in. In machining, bore out the die about
186 AMERICAN MACHINIST SHOP NOTE BOOK
0.015 in. smaller than the finished size, giving it an even curve as
shown.
The center illustration at the top shows the wrong curve in
drawing dies ; this has a great tendency to stretch and thin the
stock. At point B, the die should measure what it will when
finished, leaving the ironing surface to be finished after harden-
Jfecess
\
j
I
Vourrfersunlr
FIG. 141 DETAILS OF DIE, PUNCH AND HOLDERS
ing, by grinding. The curve can be finished in the lathe with
a three-cornered scraper, then polished with a carborundum
pencil and kerosene, and finally with fine emery cloth and oil.
The quality of work turned out and the life of the die depend a
great deal on the curve and its finish.
The die blanks can all be turned in a turret lathe. It is then
only necessary for the toolmaker to true up the blank, bore out
the die and polish.
About three sizes of die blanks will be found enough for the
average run of work. This necessitates only three different
sizes of die holders, and I believe the one shown will be
found about as handy and inexpensive as could be desired. It
is made of cast iron, bored out a sliding fit for the die blanks,
and two holes tapped on opposite sides for capscrews, which
draw down on the straps and hold the die in place. The ears on
DIE AND PRESS WORK 187
the holder provide means for keeping the die holder on the bol-
ster plate. When it is necessary to change dies, loosen the
straps, lift out the die, slip in another, and the job is again
ready to run.
Drawing punches are another interesting feature of press-tool
equipment. The one shown will be found economical from
every standpoint.
First decide upon the necessary sizes for the threaded end.
Let us say % in., % in., % in. These can be turned in the turret
lathe, then cut off to the proper length for the punch. When it
is desired to make up a set of punches, these pieces can be given
to the toolmaker along with a suitable holder to strap on the
faceplate. One of the small cast-iron die holders with hard-
ened-steel plug in the center makes a good one. It is then a
simple matter to true up the holder and turn as many punches
as desired with one setting. Drawing punches should be ground
slightly tapering, so that the work will strip more readily when
withdrawing the punch.
The punch holder is shown in the lower left hand corner.
When changing punches, fasten a dog onto the punch; a few
blows with a hammer on the dog will loosen or tighten the punch.
The punch holder should be hardened and ground all over.
I prefer the two-piece double-action dies, with the retaining
ring in place, as shown at the lower left hand corner. They
are self-centering throughout. The chief features in their favor
are that when one-half breaks or wears out it can be replaced,
and the die is as good as new. When experimenting with a new
job either half can be ground larger and "doctored up" to get
the desired result, something quite impossible with a one-piece
die.
After a drawing die has run awhile, it will be quite likely to
allow the work to come back with the punch. This is because
the lower edge has become rounded. To remedy this, grind the
under side by holding both edges of the hole against the circum-
ference of an emery wheel, which will make it slightly cup
shaped and give it a sharp edge to strip the work. Many die
makers do not approve of stripping by means of the lower edge
of the die and more or less complicated spring operated strippers
are made to close around the punch after the work has been
pushed clear through the die and stripper.
188 AMERICAN MACHINIST SHOP NOTE BOOK
PIERCING OBLIQUE HOLES
The die illustrated in Fig. 142 was designed to pierce the holes
in the piece shown. The cast-steel blank holder A is suspended
from the cast-iron secondary ram B by the guide pins C, pressed
in A and a sliding fit in B. The springs Z> transmit the power
for the blank holder A. The links E were hinged on the second-
FIG. 142 DIE FOR PIERCING OBLIQUE HOLES
ary ram and on the punch forcers F, which in turn were pivoted
in the lugs cast integral with the blank holder. The punch hold-
ers 6r, which are a sliding fit in A, carry the piercing punches H.
The hardened-steel pin I is pressed into the punch holder G and
serves as a rest for the forcer F, which is cut out square to
allow for the angular movement of the punch holder. The but-
ton dies J are pressed into the cast-iron base K.
The illustration shows the die at the bottom of the stroke.
The die operates as follows: The blank holder A and the sec-
ondary ram descend as a unit, until the blank holder strikes the
DIE AND PRESS WORK
189
piece to be pierced, holding it securely on the die. The second-
ary ram continues its downward course, setting the toggle ar-
rangement in motion, thus piercing the holes. On the return
stroke the ram B ascends, withdrawing the piercing punches
and stripping the work. The blank holder A remains station-
ary until the nuts L bottom in the counterbored holes. The
ram and the holder then ascend as a unit.
A FREAK SHELL ITS CAUSE AND CURE
Sometimes, when putting through a lot of brass shells similar
to the one shown at B, Fig. 143, a number of so-called freak
shells are discovered. For some unknown reason these are out
of shape. While there are a number of causes that result in
"freak shells," there are times when one can offer no good
reason.
A good illustration of a freak shell is shown at C, while the
shell as it should be is shown at B. The cause is this: When
FIG. 143 FREAK SHELL AND How IT WAS MADE
redrawing the large diameter, an unusual amount of the soap-
water lubricant used for redrawing the shells, was occasionally
left in the bottom of a shell. As the solution could not escape
quickly enough through the air hole in the ram when the punch
descended, the result was that the solution ahead of the punch
acted on the shell in a manner similar to that illustrated at D.
This in turn caused the bulged part of the shell to be forced
through the redrawing die without being operated on by the
punch, which in turn caused this part of the shell to bulge after
it was forced through the working part or edge of x the v die. ,
The cure for this trouble was a larger air hole in the punch, to
190 AMERICAN MACHINIST SHOP NOTE BOOK
allow the water to escape, besides keeping the lubricant out of
the shells as much as possible, preparatory to feeding them to
the die.
BENDING DIES FOR TUBING
I submit the following described and illustrated method for
accomplishing the work of bending seamless-steel tubing of % in.
diameter with 0.030 wall. As the tube will come in lengths of
10 or 12 ft. the first operation will be cutting the pieces to length,
which can be quickly and satisfactorily performed with an abra-
sive-wheel cutting-off machine. These little machines will cut off
FIG. 144 THE FORMING OPERATION
tubing very rapidly; one installed by the writer for cutting off
tubing about %6 in. in diameter was operated by a boy at a piece-
work price of 3c. a hundred pieces.
In order to form these pieces on the punch press, which has a
4-in. length of stroke, I would make the die shown in Fig. 144.
The punch holder A would contain two driving punches shoul-
dered to fit the tube, as shown at B and C. The curling die D
would be made in halves to facilitate machining the curved hole,
and these halves would then be doweled and screwed together
permanently. The die would have to be fitted to a sliding base,
DIE AND PRESS WORK
191
as it would be necessary to employ one stroke of each punch in
order to force the tube into the die to a distance of 7% inches.
With the die in the position shown at the left the first stroke
of the short punch B would force the tube about 3% in. into the
die. The operator would then slide the die to position shown at
the right for the second stroke, and the long punch C would force
the tube the remaining distance into the position shown at E.
Another tube would then be inserted and the next stroke of
punch B would force the first tube into the position F. Upon
the following stroke the punch C would eject the finished tube
from the die. A completely bent tube would thus be produced
at every other stroke of the press.
The sliding die would of course have to be equipped with suit-
able guides and positive stops.
SPRING OPERATED PUNCH PILOT
The blanking of some pieces of Vs x 1%-in. cold-rolled sheet
steel, into which a hole was also pierced, resulted in a split
punch, due to an error of the operator in not properly locating
the stock. The pilot used when this occurred was inserted in
the blanking punch as shown to the left in Fig. 145. The punch
7\ A
FIG. 145 VARIOUS TYPES OF PILOTS
was then drilled as shown at the right, which allowed the pilot
to move backward into the punch in the event of a miss. This
eliminated any further damage to the tools, but it was necessary
to reset the tools whenever the operator made an error. In the
sectional view is shown how all these difficulties were overcome.
When a miss is made, the pilot is pushed back, and on the return
stroke the spring A forces it back into position again.
SECTION X
GAGES
GAGE GRINDING MACHINE
Two machines or fixtures similar in general construction to the
one shown in Fig. 146 were built a number of years ago for the
sole purpose of grinding gages. They were found to be conven-
ient and rapid.
At A is the grinder head and at G the sliding member, or
platen, which is operated by the rack and pinion P and fitted to
the base H. The head is movable on the ways, and the whole
outfit is mounted on a cast-iron baseplate.
In practice the gage to be ground, shown at X, is clamped to
the platen J. The grinder head is then brought to position for
the wheel to engage the work. The straddle clamp G is then
secured to the ways and the wheel fed to its cut by the gradu-
ated screw H.
The slide J is operated by the hand lever L. The depth of the
cut is regulated by the stop R, the adjustment being made by the
knurled-head screw 8. One side of the gage being ground, the
head is moved to the other side, or face, of the gage and the oper-
ation repeated. The work remaining in the same position in-
sures the faces being ground parallel to each other, provided the
same care is taken as would be the case when using any other
method or machine for the same work.
The spindle B runs in the bronze bushings C. These bushings
are made long enough to project beyond the inside faces of the
casting to within about ^ in. of each other, thus forming the
bearing for the driving pulley D. A slot in the spindle allows
the pin E to pass through with clearance all around. The pin
is a light drive in the pulley. This arrangement provides a
means for driving and also takes the belt pull off the spindle,
thus insuring greater accuracy.
End play is taken up by the adjusting screw F, in the rear
end of the spindle. This screw bears on the pin E, and as pres-
192
GAGES
193
sure is applied the pulley is forced against the collar, and the
flange on the shaft is brought up to its bearing on the face of the
casting, thus effectually taking up all end motion. No provision
FIG. 146 THE GAGE GRINDING MACHINE
is made for wear of the bushings, although this could easily be
provided for in the usual way with taper bushings and threading
the collar.
194 AMERICAN MACHINIST SHOP NOTE BOOK
The height of the platen / is such as to bring the center line
of the work in line with the center of the spindle.
SPECIAL V-BLOCK FOR GRINDING WORK
Recently in a munition-shop gageroom in Canada I was called
upon to grind certain gages upon all four sides as well as the end,
at one setting of work ; hence, the development of this V-block.
Fig. 147 shows a sample of work required to be ground upon
all four sides as well as the end, and it also shows the V-block
assembled ready for the grinding operation. The two 10-size 32-
thread side-clamping screws can be seen. The ordinary clamp-
ing device shown over the small V is of course removed when
rolling the block while grinding the work.
FIG. 147
The opening in the large V of the block is somewhat larger
than the maximum-diameter yoke ring, so as to give a tightening
movement of Vs in. The yoke is made of rough stock % in. wide
and tapped for a %-in. by 20-thread screw. The yoke clamping
screw, as well as the side pieces, is shown in this view. The side
pieces are made with a gib, as shown. Everything is accurately
ground ; and without going into details, it may be said that the
aim is to have the V's central with the sides of the block with or
without side pieces.
DEVICE FOR MEASURING THREAD GAGES
What manufacturer of threads has not been annoyed by the
old, slow and somewhat inaccurate method of measuring thread
gages with three wires? I certainly was much worried by the
diversity of measurements taken in this manner by different
inspectors on the same gage. After considerable thought, the
rather simple device illustrated in Fig. 148 was evolved. It was
GAGES
195
FIG. 148 THE
MEASURING
DEVICE
comparatively inexpensive and has proved to be very useful for
the operations for which it was made.
It is made of a simple casting with a split hole bored in the
top. A commercial micrometer head is set in the hole and held
by a binding screw. A hardened, ground and
lapped steel block is set into the base, the face
of the block being set parallel to the face of the
micrometer spindle.
Two of the wires are laid on the face of the
block, and on top of these the gage is placed.
The third wire is placed between the top of the
gage and the spindle of the micrometer. By
slowly rolling the gage through this contact, a
very good "feel" can be obtained. Experience
has shown that various inspectors will obtain
the same reading, within very close limits, from
the same gage.
Measurements can be checked by using stand-
ard blocks or plugs (without the wires). A
further check as to the accuracy of the wires
can be made by using a standard plug between the wires.
The greatest care should be taken to see that the wires are
uniform in size, perfectly round and exact to a known diameter,
since any error in the size of the wires is multiplied by three in
the result. The easiest way to get accurate wires is to buy com-
mercial sewing needles, lap them round and to a known size in
sets of three, and cut off the tapered ends. To prove the accu-
racy of a gage it is advisable to use two or three sizes of three
wires. The formula to be employed can be found in any good
machinists' handbook. The device gives a range of measure-
ments from to 3 in. The one illustrated measures from 2 to
3 in., while by using a 1-in. block on top of the base measure-
ments can be had from 1 to 2 in., and with a 2-in. block from
to 1 inch.
Since writing the above, it has occurred to me that two lapped
prisms of a known height and of a suitable angle for the thread
under inspection could be used in conjunction with the wires.
It would also be necessary to have a flat lapped block the same
thickness as the prisms are high. With these one could measure
the outside diameter and single depth of thread of the gage.
196 AMERICAN MACHINIST SHOP NOTE BOOK
PROBLEM IN GAGE TESTING
The gage shown at A, Fig. 149, was given me to be "checked
up." The angle on the test piece B was not given. Taking
0.152 in. as the side opposite and 0.1655 in. as the side adjacent,
I found by the ' * American Machinist Handbook' ' that the angle
was 42 deg. 34 min.
I made the test piece B of Vs B. & S. flat ground stock. To do
this accurately, it was necessary to know the distance from the
apex C to the base. Referring to D, the hypotenuse is 0.152 in.,
Test
Piece
FIG. 149 A PROBLEM IN GAGE TESTING
and 0.73719 is the sine of 47 deg. 26 min. Multiplying 0.152 in.
by 0.73719, we have 0.1120 in. as the distance from the point C
to the face of the angle.
With the aid of a sine bar the test piece was then set up at an
angle of 47 deg. 26 min. on an angle plate. The height gage was
set to the corner C, and 0.112 in. was ground off each corner.
All this should perhaps have been done in the drafting room ; but
few draftsmen make provision for the production of such work
or give a thought as to how the toolmaker is to do it.
THE USE OF PEELER GAGES
Fig. 150 suggests another of the many uses to which the ordi-
nary feeler gage may be put by the machinist who is not pos-
sessed of an internal micrometer.
The tube A, which can be of brass or any suitable material, is
divided in the center by B, which is about % in. thick ; the ends
are drilled to take the steel rods D and E. The center of the
tube has an opening C, to allow for the insertion of any desired
feeler gage.
GAGES
197
Suppose it is desired to bore a hole several thousandths of an
inch larger than a diameter already turned. The gage is first
adjusted to the finished diameter by means of the rod D, which
FIG. 150 INTERNAL GAGE USED WITH FEELER
is clamped in position by G. The feeler gage of required thick-
ness to give the difference in diameter is then slipped between
the inner face of the rod E and the portion B, and E is then
clamped in position by F. The gage is then ready for use.
I saw this gage in the hands of an old mechanic who might
now be considered out of date, but it certainly has all the accu-
racy, though perhaps lacking the convenience, of our more
modern instruments.
ADJUSTABLE FEMALE THREAD GAGE
Fig. 151, which is self-explanatory, shows a female thread
gage that has met with high favor in the place where I am
IkV-J
41!
ITEM
NO.
TOOL
NO.
PffRT
NO.
THREAD
PITCH
DfffM.
fffO'D
DEP7
1
0-MK
PD?74
08S'!7RHUSS
a7572"
2
It
2
pfff44
002-159
1375'*!? LHtiS*.
1.5209"
Z
12
3
OMSK
SD-HOIB
?75"*8RHUSS.
2.6689"
12
<?
5
omt
miszo
Z.50**8f?.HUSS.
24189"
2
3
Ktt-2
2.875"* 16 LHUSS.
Z8WS"
2
IS
FIG. 151 ADJUSTABLE FEMALE THREAD GAGE
198 AMERICAN MACHINIST SHOP NOTE BOOK
employed. I believe it will be of use to others. Notice the
handy method of tabulating.
A GAGE FOR DEPTH OF RECESSES
Fig. 152 shows a form of feeler gage which is being
used on airplane motor work. It consists of the feeler A, to
which the knurled body B is attached by driving a dowel pin
A
FEELER
FIG. 152 A FEELER GAGE
C into a reamed hole in the body and engaging a recess in the
feeler. The dotted lines indicate the part to be measured. The
gage is very simple and has proved durable in service.
FEELER GAGE FOR RECESSES
Fig. 153 shows a gage for measuring the diameters of
recesses. The recesses in the case on which the gage was em-
ployed had a limit of 0.010 in. The illustration shows the gage
at the low limit. When at the high limit the end of the pin A
is flush with the face B. The angle at the other end of the pin
A is 45 deg. Pockets are formed in the gage 0, to receive steel
balls D, and the edges of these pockets are peened over to pre-
vent the balls from dropping out.
The end of the pin A, having the, angle face, abuts against one
of the balls, and moves it outwardly in the desired degree. A
setscrew E is provided for holding the pin A in place. The dis-
tance G should be less than the distance H to permit the pass-
ing of the gage.
GRINDING CORRECT RADIUS ON A GAGE
Given three gages to make, as in Fig. 154, I used the follow-
ing method. Three blank pieces were machined on all flat sides,
DETAIL OFGAGC
FIG. 153 FEELER GAGE FOE RECESSES
FIG. 154 THE GAGE AND TEMPLET
199
200 AMERICAN MACHINIST SHOP NOTE BOOK
and another piece of Vik-m. steel the same size wa^ added.
These were clamped together and drilled for two dowel pins. I
laid out the large hole on the thin piece, as I kept this on top,
clamped the pieces on the faceplate of the lathe and bored them
out, leaving enough for grinding. The thin piece was then taken
off and the others machined.
After hardening and grinding on the flat surfaces, I put the
whole together with the dowel pins, the thin piece being on top.
I then fastened them on the faceplate of a bench lathe and, indi-
cating the hole true, I ground them out with an internal grind-
ing attachment, making the hole 0.780 in. in diameter, thus
giving me the correct radius.
BUILT-UP LIMIT SNAP GAGE
Several sets of snap gages of different sizes ranging from 1^
to 4 in. were wanted in the machine shop. The company had
taken a medium-sized order for screw-machine products ; and as
this was a special rush job, the necessary limit snap gages were
needed in a hurry.
FIG. 155 BUILT-UP LIMIT SNAP GAGE
After due consideration a design was determined upon which
gave a serviceable tool that could be made in a fraction of the
time usually required in making the conventional limit snap
gages. Fig. 155 shows the construction of one of these gages.
GAGES
201
Although it is rather homely in appearance, it is just as accurate
as any high-class snap gage.
The gage itself is made of four pieces the sizing block A and
the side pieces B, C and D all of which are made of tool steel
hardened and ground on their contact surfaces. The long side
piece B is secured to the sizing block with three fillister-head
screws, while the short pieces C and D are each held by two
screws to the block A. The groove E in the sizing block is for
the purpose of facilitating grinding to size. The gaging sur-
faces F of the side pieces were lapped smooth on a flat lap after
grinding.
These gages were found to be satisfactory in every respect.
They were accurate and durable; and when worn, all that was
necessary in order to correct the error caused by wear was to
remove the seven screws holding the various parts together, and
lap the surfaces F straight and smooth.
AN AMPLIFYING GAGE
To assist in the rapid inspection of pieces made by students
taking a course in machine work at the Ohio State University
an amplifying gage has been devised by the instructors and built
FIG. 156 AN AMPLIFYING GAGE
by students who are taking advanced work. As may be seen in
Fig. 156 the principle is an old one. A lever having a ratio of
10 to 1 is employed, so that if the gaging point be raised 0.0001
202 AMERICAN MACHINIST SHOP NOTE BOOK
in. the indicating end will be raised 0.001 in. A dial indicator
is attached to the long end of the arm and its readings thus be-
come 0.0001 in.
All moving parts are hardened and ground or lapped as nearly
as possible. The base is of heavy surface-plate construction re-
inforced by ribs to absorb all vibration. A is a piece of hardened
steel ground true and parallel which serves as an anvil on which
the piece to be tested is placed. Adjustment is provided at B to
bring the dial reading to zero, this first reading being obtained
by a standard test block. With this instrument a number of
pieces can be rapidly checked showing variation correctly to
0.0001 in.
We find this gage to be of material assistance to the student
in making duplicate pieces, and while it seems very difficult for a
beginner to judge the amount of pressure on the micrometer
screw when taking readings to 0.0001 in., with this instrument
the personal equation is practically eliminated.
INSPECTION GAGE
Fig. 157 shows a gage used mainly by the inspection de-
partments. The inspector puts a number of parts to be gaged
on the base A and then simply pushes the work under or through
the gage. The same idea can be carried out for gaging work with
several diameters and shoulders. All the parts are made of tool
steel hardened and ground, and when necessary lapped.
\OOI
No6o<
v:.v
-AUXQGoV.
0.166 No Co
-0.168 Go
FIG. 157 THE INSPECTION GAGE
GAGES
203
ERRORS IN MEASURING THREAD PITCH DIAMETERS
WITH WIRES
The pitch diameter of threads measured by wires often differ
from measurements taken with pitch micrometers.
With micrometers reading correctly there are four factors, any
or all of which may cause the wires to give a different result.
The first and most important is the size assumed for the wires
themselves. Many seem to think that if the wires are known to
be correct to 0.0001 in. the resulting pitch diameter will have
FIG. 158 How THE ERROR is MULTIPLIED
like accuracy. A consideration of Fig. 158 will show this
assumption 200 per cent, in error. Let the large circle rep-
resent the actual size of the wire, and the small circle the size
assumed. If -^ represents the difference in the radii then the
error made in measuring the wire diameter was D in. For a
60 deg. thread it will be seen from the right triangle ABC that
the assumed wire has its center a distance D nearer the thread
axis than the center of the actual wire. The point of contact K
between the micrometer and the actual wire has to advance, in
order to get to a similar point on the assumed wire, this distance
D plus the shortening of the radius 75-, or a total distance % D.
z
That is, the plain micrometer reading, on one wire, will be in
error l l /2 times as much as the measurement of the diameter of
the single wire is in error. If the two wires on the other side
of the thread have the same error as the single wire, the microm-
eter measurement has three times the error of the wire measure-
204 AMERICAN MACHINIST SHOP NOTE BOOK
ment. For Whitworth threads the figure becomes 3.17. This
means that wires measured with the common micrometer cannot
be depended upon to give pitch diameter results closer than say
0.0002 in. Wherever possible wires should be measured in a pre-
cision machine such as Pratt & Whitney or at least checked with
Johansson blocks.
Given wires of known diameter it is still necessary to handle
them much as soap bubbles would be treated in order to prevent
further error. Whereas pitch micrometers make line contacts
on the threads, wires make theoretical point contacts and very
little pressure will wedge them down into the threads sufficiently
to distort the surface at the contact points. A good way to
demonstrate this difference is to carefully measure two wires,
and compare the sum of their diameters with what is obtained
by crossing the two, and measuring overall.
A third factor arises from the nature of the surface on the
sides of a lapped thread. Thread lapping is about the only kind
of lapping where the cutting lines cannot be crossed. The mo-
tion of the cutting abrasive of the lap is always in helices con-
centric with the thread axis. The result is furrows and ridges
which will be large, pr small according to the size of the abrasive
grain but they are always there. If they are large the reading
of pitch diameter is considerably affected by whether the wires
make contact on the tops of ridges or lie in the furrows. Hence,
checking the thread angle with sets of wires of different size can
only be done accurately when the sides are quite smooth. It
need only be mentioned that if the thread angle differs from the
angle of the pich micrometer spindle or anvil, medium-sized wires
will give a lower reading than the micrometer on that account.
This may look like a clear case against wires, but when there is
discrepancy between the results they give, and the pitch microm-
eter reading it is poor policy to convict the former without first
cross-questioning the latter. The pitch micrometer has plenty of
faults. If, for instance, thread gages are being measured, which
are nearly uniform in pitch diameter, flat spots will develop
on the sides of the spindle in a surprisingly short time. This is
particularly so where the thread angle is wider than the spindle
angle. In any case where pitch micrometers are used on a num-
ber of the same sized gages it is good policy to check frequently
on a master of the same size set apart for this purpose.
GAGES 205
From the above considerations there is no magic required to
explain why the wires so often differ from the micrometer. In
general the wires will be found to give a lower, rather than a
higher reading.
PLASTER OF PARIS FOR SEALING HOLES IN GAGES
In the making of sectional gages, adjustable gages or various
other mechanical devices, it is desirable to seal screw holes. The
curiosity of man being always prevalent, it is wise also to seal
the inspector's adjustment or the toolmaker's precision that they
may not be tampered with.
Red sealing wax commonly used, suits the purpose, but it has
been found from experience that sealing wax is difficult to apply
to steel. It hardens too rapidly to get desired results, and often
necessitates a second application. The idea of using plaster of
paris came to the writer when several holes were to be sealed on
some indicator gages; and as the holes were quite conspicuous,
sealing wax was undesirable and did not properly fill them.
Plaster of paris was tried and found superior to wax. The plas-
ter dries rapidly and requires no haste in applying.
The proper way of using plaster is to get all materials in readi-
ness before mixing the desired amount; and if numerous holes
are to be sealed, it is even better to mix a very little at a time,
thereby eliminating unnecessary waste.
A small scale can be used for mixing and applying; if after
filling a hole the plaster is rough on top, moisten the scale slightly
and pass it over the plaster with enough pressure to make the
plaster flush with the top; scrape particles oft' and a neat ap-
pearance results.
Plaster is easily removed if need be, and moisture evaporates
from it so rapidly, there is little danger of rust resulting from
the water used in mixing.
GRINDING SNAP GAGES
I use what I call a "snap gage wheel," which is shown in
Fig. 159. Of course, wheels that have been recessed on the
sides by hand, have been used in some shops for years, but it
is only recently that I have heard of a wheel-maker putting
206 AMERICAN MACHINIST SHOP NOTE BOOK
one on the market, and then in only one size, that is % in.
face by 6 in. diameter. This is good for the average run of snap
gage work, except in sizes of $16 in. or less. Worn wheels may
GRINDING
HfH-
FIG. 159 SNAP GAGE WHEEL
be worked down to V\ in. or even less on a pinch, but if this is
done considerable care must be used to see that they are not
handled roughly.
SECTION XI
GRINDING
KEEPING NOTES ON GRINDING
SOMEWHERE I have read, or have heard, that, provided enough
steadyrests are used, it makes no difference whether or not the
piece of work to be ground is long or short, solid or hollow the
same amount of stock can be removed per minute; but my own
mind is far from being satisfied on this point. For one, I can-
not grind long, slender work or thin tubing with anywhere near
the same degree of rapidity that I can grind a solid bar. If it
were possible to remove say % cu.in. of stock per minute in the
roughing operation from any piece, regardless of its length, ten-
sile strength or cross-section area, and to remove % cu.in. of metal
per minute in the finishing operation continuously, then the keep-
ing of performance notes would be a useless task and the matter
of establishing piecework prices would resolve itself into the
formula for finding amount of stock to be removed, ~r^(D~ d 2 ),
times the amount to be allowed the operator per cubic inch.
As things stand with me now, I sometimes am at a loss whether
to estimate % cu.in. a minute, less or more, and in all cases I
make sure to verify my figures by looking through my notes of
past performances for a sketch that most nearly approaches the
one on which I am figuring.
My notes tell me that conditions must be very favorable to
permit the operator to remove 1 cu.in. of stock per minute, ex-
cept the operation by a draw-in cut, as in the rough grinding of
crankshaft bearings made of soft drop forgings. In this I find
that I can remove l 1 /^ cu.in. of stock per minute day in and day
out, plus the handling of the shaft.
Notes Should Be Profitable to the Operator. Notes on grind-
ing should not be kept by the operator solely for the purpose of
being able at some indefinite date to estimate the grinding time
207
208 AMERICAN MACHINIST SHOP NOTE BOOK
for others, but should be kept in a manner to enable him to profit
daily by that which he has recorded. For instance, suppose that
at a periodic interval of about every three weeks (long enough
for him to forget the details of the job) some machinery steel
shafts 26 in. long, 3 in. in diameter, and with 0.025 in. of stock
to remove should come along for him to rough and finish grind
at the rate of seven an hour, what wheel should he use, what
work speed, what table traverse, and what depth of cut per pass ?
To find the most efficient combination he would have to juggle
these variables until he hit upon the correct assortment to turn
out his seven shafts per hour, but in the meantime valuable time
(which means money to him if he is on piecework, and money to
the company if he is on either piecework or daywork) would be
lost. If notes on each shop job were kept, how easy it would be
for him to set his machine approximately right the first time.
For example, let us take this shaft on a 10 x 50-in. Norton plain
grinding machine :
Shop Order Number 8454.
Article Vertical shaft.
Material Machinery steel.
ROUGH GRINDING
Wheel 24 combination N, Norton.
Work Speed Cone pulley- sixth step, fast lever.
Table Traverse Cone pulley sixth step, fast lever.
Depth of Cut 0.002 in. per pass.
FINISH GRINDING
Wheel 24 combination M, Norton.
Work Speed Cone pulley fourth step, slow lever.
Table Traverse Cone pulley second step, slow lever.
Depth of Cut 0.0005 in. per pass.
Such notes could not help but prove of value, all the more so
if accompanied by a sketch of the work with diameters and
limits.
Use of Speed Tables. In my work as a cylindrical grinding-
machine operator I wrote into my notebook a list of all work
speeds and table traverse speeds for each pulley and then, when
a new job came along, I was able to test out intelligently differ-
ent combinations of speeds. In figuring work speeds I used a
GRINDING 209
constant that aided greatly in making the computation a simple
mental example. It would have been possible to have made it
more simple by the use of a graphical chart, but this was an
afterthought that came much later. My method of determining
pulley speeds and the use of the constant is worth illustrating.
Taking a 10 x 50-in. Norton plain grinding machine on which I
worked for several months, my notebook gave me the following
speeds, together with the constant:
10 x 50-IN. NORTON, MACHINE NUMBER 988
R.p.m. of Work Drive
R.p.m. R.p.m.
Step on Pulley Fast Lever Constant* Slow Lever Constant*
Fastest 193 50.5 76 19.9
2 137 35.9 56 14.7
3 110 28.8 46 12
4 95 24.9 38 10
5 82 21.5 33 8.6
6 74 19.4 29 7.6
TT X r.p.m.
* Constant =
12
TABLE TRAVERSE IN INCHES PER MINUTE
Step on Pulley Fast Lever Slow Lever
Fastest 148 50
2 120 40
3 100 33
4 88 29
5 75 25
6 67 22
7 60 20
8 55 18
Suppose that the 3-in. shaft mentioned should come to me for
the first time and I decided, on looking it over, to try a rough-
grinding work speed of 60 ft. per min. Sixty feet divided by the
diameter 3 gives me 20. Looking at my list I find that the near-
est constant to 20 is 19.4, and that I must run the work at the
revolutions per minute the constant indicates, or 74-r.p.m. This
is the sixth pulley step, using the fast lever. Now, with a grind-
ing wheel 2 in. wide, it is correct to rough out with the full face
of the wheel to each revolution of the work ; therefore the revo-
lutions per minute of the work times 2 in. will give the table
traverse in inches. Then 74 times 2 equals 148 in. as the table
210 AMERICAN MACHINIST SHOP NOTE BOOK
traverse, or the first pulley step, according to the list of speeds,
using the fast lever.
Assuming 30 ft. per min. to be a good work speed in the finish
grinding of such a shaft, I divide 30 by the diameter 3 and,
looking at the list of speeds for the constant nearest to 10, I find
that the belt for a work speed of 38 r.p.m., as indicated by the
list, should be on the fourth pulley step, using the slow lever.
In finish grinding using one-half the width of the wheel (1 in.)
I have a table traverse of 38 in., or the second pulley step, and
the slow lever.
Tables like this, on different machines, were of great help to
me in my grinding.
Innumerable details only casually impressed on a person's
memory cannot be considered a future asset. In the keeping of
notes there is a feeling of a sense of reliance on one 's own ability,
backed up, not alone by a varied experience, but by positive, re-
corded, demonstrable facts.
MOUNTING, BALANCING AND DRESSING GRINDING
WHEELS
In many of the factories where production grinding is being
done, I have found that each operator is permitted to dismount
his old wheel and remount a new one, dress off the sides if accu-
racy in width is desired with a straight in cut, and then balance.
I have found by experiment that a considerable gain in produc-
tion can be obtained by specializing on this work. The parts
ground in this experiment were crankshafts, the concern having
an output of between 600 and 700 per day.
A new operator will take two or three hours to set up a new
wheel and usually requires the assistance of an older head be-
sides. We were losing this amount of time from thirty to forty
roughers weekly, by using the above method, and also several
wheels, through the inability of operators to dress their wheels
to proper size.
By training a special operator in this work we gained many
hours of labor and also obtained better results in the size of our
wheels. Using a grinding machine exclusively for this work,
with an operator trained to this method, we obtained speed and
accuracy.
GRINDING 211
Care should be taken to keep each wheel mounting clean from
dirt and burred-up points. Aside from this no difficulty is ex-
perienced, as all grinding-machine spindles are ground to a
standard taper and the mountings are interchangeable. To in-
sure even better results two mountings should be numbered to
correspond with the number of the machina on which they are
used.
SAVING TIME AND ABRASIVE WHEELS
We have in use a great many special-form abrasive wheels for
grinding and regrinding a certain class of tools. These forms
require extreme precision and necessarily consumed a great deal
of time in dressing the wheels. In removing these wheels from
the spindle of the grinder and replacing them at a future time
for regrinding the same job, it was always necessary to redress
the wheel, owing to the fact that it was impossible to replace
them on the spindle again so that they would run true. We
bought a lot of abrasive-wheel centers (or bushings on which
the wheels are mounted on this particular grinding machine),
and instead of removing only the wheel we remove the entire
abrasive-wheel center, leaving the wheel mounted on it while
not in use. These abrasive-wheel centers are interchangeable on
the No. 13 B. & S. universal grinder and the No. 2 B. & S. sur-
face grinder. In this way they may be used on either machine,
and when they are replaced they run perfectly true without re-
dressing, only requiring redressing when they wear out of shape
or become glazed. The cost of the abrasive-wheel centers is very
small, in fact less than the cost of dressing some of our abrasive
wheels.
We have at the present time at least fifty wheels of different
shapes stored away that will not be removed from the emery-
wheel centers until they are worn out.
GRINDING THE EDGES OF CIRCULAR PLATES
A unique method of revolving a circular plate during grinding
operations on its edges, is shown in Fig. 160 of a device which
takes its power from the traction of the wheels upon which the
carriage runs while traveling back and forth past the surface of
the grindstone.
212
GRINDING 213
The usual custom is to accomplish this movement by means of
a countershaft and belt, the tendency of the latter being to lift
the carriage away from the grinding medium, thereby causing a
variation of pressure with resultant unevenness of work.
Two miter gears B mounted upon axle A, carry four pawls in
their respective hubs ; one set being operated by a right-hand,
the other by a left-hand ratchet ; these pawls and their springs
are retained by the steel ring C which slips over the hub. The
third miter, meshing with the two gears upon the axle, is
mounted on the end of a short shaft lying parallel with the line
of travel of the carriage; this shaft carries a sprocket which
drives by means of the chain, the sprocket wheel D mounted upon
a sleeve with the gear E.
This gear through the medium of the pinion F, the worm G
and the wormwheel H, turns the disk / with a powerful and uni-
form movement in one direction regardless of the direction of
movement of the carriage.
The transmission of power through the sleeve, gear and pinion
allows the bar carrying the disk, to be turned upon its own axis
for the purpose of tilting the disk to whatever angle may be re-
quired ; this turning being accomplished by the worm and hand-
wheel shown at the right.
This latter feature has been found to be very convenient in a
number of instances.
WHEELS FOR TOOL AND CUTTER GRINDING
One of the most neglected places in a shop is the wheel rack of
the universal tool- and cutter-grinding machine. I never yet
have worked on a tool- and cutter-grinding machine where I did
not feel like apologizing for my poor assortment of wheels.
Neither have I seen in any factory a rack having an equipment
of wheels that approached the ideal. Where the use of the ma-
chine is open to all toolmakers in a toolroom, the condition of
the wheels is generally deplorable. A toolmaker as a rule will
go to the machine, select a wheel (generally the best-looking
wheel in the rack) and if it is not exactly the shape he wants
he will unhesitatingly dress it with the diamond to suit himself.
Sometimes this spoils the wheel for its original use.
The large majority of racks contain worn-down wheels in
214 AMERICAN MACHINIST SHOP NOTE BOOK
plenty, and the operator usually has to make the best use of
these that he can. This is not fair since the requirements of his
work are such as to demand the use of the best wheels obtainable.
Good operators are decidedly scarce, and one of the best ways
to hold them in the factory is to give them the assortment of
wheels for which they ask. To call down an operator for doing
an indifferent job of grinding when the proper equipment for
the work has not been furnished him, is one of the short cuts
toward losing his services, especially if he has requested the pur-
chase of some particular wheel and did not get it.
Toolroom foremen should familiarize themselves more com-
pletely with the particular needs of the tool- and cutter-grinding
machines. If the operator is a man of sense and experience, and
asks for a wheel of a certain grade and grain, give him that
wheel. He surely must know what he wants, so do not overrule
his judgment. Many a job that takes three hours to grind could
be done in an hour if the wheel assortment were more varied as
to grain, grade, shape and size. I remember not long ago, one
toolroom foreman who persisted in buying for me such wheels as
80 and 100 L Norton when I specially requested 38-46 K and
38-60 K Norton. He did this while still admitting that I ap-
peared to know more about grinding wheels than any man who
had previously worked for him.
A hard wheel will inevitably cause temperature changes, and
a consequent distortion of the work, even though the discolora-
tion usually associated with excessive heat may not appear on
the surface.
A good wheel list for the grinding of such carbon steel and
high-speed work as plain milling-machine cutters, formed cut-
ters, gear cutters and inserted-tooth milling cutters is not a for-
midable list to remember. Taking the Norton vitrified alundum
wheel for example, the job can be done with one or the other of
the following wheels : 38-46 J or K ; 38-50 J ; 38-60 I or J, and
using 5000 surface ft. per min. as a wheel speed. There is noth-
ing difficult to remember about this simple list of wheels, all of
which should be in the wheel rack.
It is always important in giving the grain and grade of the
wheel to state the maker's name, by reason of the fact that dif-
ferent wheel manufacturers have not adopted a universal method
of marking.
GRINDING 215
GRINDING THIN PIECES
I was given a bunch of old hacksaw blades that had been worn
out or broken in the power saw. From them I was to obtain
stock to make size pieces for inspection purposes. These pieces
were to start at 0.030 in. thick and run up to 0.050 in. thick,
leaving stock to lap, each piece to be 0.001 in. thicker than the
other. After grinding the teeth flush with the back of the
blades, I clamped 10 of them together, side by side, and placed
two flat vises parallel to one another and parallel to the wheel
on the magnetic chuck. I put the saw blades in the vise, leaving
them sticking up above the jaws about % in.
The portion protruding above the jaws I clamped together
with "Brownie clamps/' one clamp to each vise and one in the
space between the vises. These clamps were to hold the blades
rigid. They also prevented chatter, which is likely to occur
where uneven surfaces, due to hardening, are placed together.
Moreover, when the jaws of the vise were opened to move the
blades forward the proper length, the pieces were held together
tightly enough so as to prevent movement of the blades, which
would cause the ends of the blades to be uneven and make the
pieces of unequal length. I then moved the table of the grinding
machine in, cutting through the soft ends with holes and cut
off about 2 in. This also served to square up the ends. The
blades were then cut to % in. lengths until the stock was used up.
Before starting to rough the stock down, I dressed the surface
of the magnetic chuck perfectly parallel with a 30-Q wheel, which
is a very good wheel for cast iron.
Now my troubles started. I laid the stock flat on the chuck
after dressing the wheel perfectly true with the diamond. I
proceeded to rough all the pieces to the same size, using a cut of
0.001 in. per each feed across. For this operation I used a new
46-G wheel, which was the best I had at hand. It was 7M x % x
1% in. I demagnetized the chuck, then placed the pieces on a
true surface plate (the inspector's) and indicated them with a
"last-word indicator." I found that they had bowed in the
middle about 0.003 in. I placed the pieces back on the chuck
without magnetizing them, so as to grind the bow out. I would
say that this was caused by two reasons by friction of the wheel
on the stock, causing heat, and by magnetism drawing the stock
216 AMERICAN MACHINIST SHOP NOTE BOOK
down flat on the chuck, whereas by throwing the switch out, it
relieved the stock and allowed it to return to its original shape.
The Second Method. This time I ground the bowed side
parallel, then turned it down to the surface of the chuck, mag-
netizing it. I used a cut of 0.0002 in. on each cross-feed. I
found that the stock bowed some, although not as much as be-
fore. This I believed was due to too much wheel surface causing
an overabundance of heat. This would not do, so I thought of
eliminating some of the cutting surface of the wheel by dressing
the wheel to a little under Vs in. wide. This plan also worked
about the same as my second attempt, still causing too much
heat, although hardly noticeable to my hand, yet enough to make
a little bow in the stock.
By this time I was beginning to wonder if the foreman did
not think I was spending too much time on the job, so I began to
do some "tall thinking." If the heat from the wheel could be
cut down or eliminated, the job would be "easy sailing. " I used
a pair of pliers and broke a piece from the wheel, perhaps ^ in.
deep and 2 in. long. On the other side of the wheel, just oppo-
site to this, I broke out a piece of about the same size. I then
dressed the face of the wheel with a diamond and went ahead
with the job. Thus, I want to impress on my fellow readers, by
hacking the face of the wheel the continuous friction of the wheel
on the stock was broken, and there was not enough heat gener-
ated to spring the steel.
The Question of Safety. Perhaps some machinists would hesi-
tate to use a wheel broken out like this, but by pinching off the
pieces with pliers I believe the wheel is not strained as it would
be by a blow from a hammer. Also, there is quite a difference
in the centrifugal force in a wheel % in. thick and of one Vs in.
thick.
I have since talked with gagemakers who have followed surface
grinding for years, also with several toolmakers, and they had
never heard of this little trick. I find that the usual method
followed by them is to ignore the amount the work bows during
grinding, the idea being merely to make the work of even thick-
ness. When this has been accomplished it is removed from the
magnetic chuck and peened straight. However, I offer this to
those who have work of this character to do and who have experi-
enced the same trouble that I had.
GRINDING
217
RADIUS WHEEL-DRESSING FIXTURE
Fig. 161 shows a radius-forming fixture for grinding wheels.
It was designed and used very successfully on wheels for gages
by R. <j. Dorval, assistant foreman of the New England West-
inghouse Co. It is a simple device, consisting of the head block
A, which supports and carries a spindle B. On the outer end of
the spindle is the frame C, and at the other end the handle D
for moving the spindle and frame past the face of the grinding
wheel.
FIG. 161 RADIUS WHEEL DRESSING FIXTURE
The frame carries the wheel-truing diamond E, which is
swung past the face of the grinding wheel by means of the
handle D. The setting of the diamond is the important part of
this work and is readily accomplished by means of the test bar
F, which in this case is 0.250 in. in diameter. As shown, this
bar is centered at each end, requiring a special center G in the
spindle B. In the later machines this center was omitted and a
female center was bored in the end of the spindle itself. This
change simply necessitated turning one end of the test bar with
a 60-deg. point, the operation being the same as with the center
shown.
Having the test bar of known diameter, it is easy to set the
diamond by means of a standard gage block placed between the
bar and the diamond point. The illustration shows the diamond
set for a %-in. radius, the diamond being % in. below the test bar,
making the radius % + ^ i n -
For making a concave radius it is necessary to set the diamond
218 AMERICAN MACHINIST SHOP NOTE BOOK
point above the center to the desired amount. This can be ac-
complished in various ways by testing from the frame C with
suitable blocks.
GRINDING A COUNTERSINK IN CHILLED CASTINGS
The casting shown enlarged in Fig. 162 is part of a manufac-
tured article that is turned out in large quantities. The open-
ing in the middle is made with a dry-sand core, and would be
quite satisfactory but for the fact that the thin wall cools so
quickly that it chills a condition that would be unimportant
except that it must be countersunk. A screw slides through the
FIG. 162 THE WORK AND THE GRINDING DEVICE
enlarged part of the opening, and to prevent the threads from
catching, the castings are countersunk or beveled at each end.
The chilled castings would ruin countersinks faster than they
could be sharpened, and this work became the one slow opera-
tion on the job. For certain reasons it was not feasible to make
the countersink a part of the core itself, and in the search for
a better method, grinding was suggested and tried out with
marked success.
The countersink grinding device was rigged up in the manner
shown. Round sticks of crystolon held in a split chuck in
the spindle of a grinding machine form the grinding medium.
GRINDING
219
A cushion of blotting paper surrounds the stick, which is tight-
ened and trued up by four screws in the ring. As the stick
wears the screws are loosened and the stick brought forward.
The sticks are dressed to shape with a Huntington dresser, the
only kind available in the shop, but reasonably satisfactory, as
the sticks do not cut or groove to the extent one would think.
A sheet-steel table is adjusted to the right height to bring the
slot in the castings central with the tool, and guides are loosely
fitted at each side to control the pieces. The workman feeds the
castings up by hand and judges the amount of bevel by his eye.
Compared to the countersink method the grinding is a ten-to-one
winner. Each night the workman has fifteen hundred pieces
well done and his wheel is good for as many more. To do the
same amount of work, a countersink of the best steel would have
been sharpened many times and would have cost as much as
several sticks of crystolon.
A FIXTURE FOR GRINDING
The fixture shown in Fig. 163 is designed for quantity
production of small castings required to be finished on a disk
FIG. 163 GRINDING FIXTURE
220 AMERICAN MACHINIST SHOP NOTE BOOK
grinding machine. The table should be fitted with a lever feed,
allowing the fixture to be clamped to table. The fixture holds
the part to be finished very firmly, and requires a minimum of
time for changing.
Referring to the drawing, the casting A to be finished is placed
against the locating stops B, between the jaws C. Turning the
hand nut to the right draws back the shaft and cam D f which
forces the jaws both inward and together on opposite sides of
the work, that is, the work is pinched, and at the same time
drawn firmly against the backstop. By changing the shape of
the jaws, the fixture can be made to hold irregular work.
DIAMOND HOLDER FOR NORTON GRINDER
Fig. 164 shows a diamond holder used for truing an 18-in.
wheel on a Norton 10 x 72-in. grinder.
FIG. 164 A DIAMOND HOLDER
The holder is made from a piece of cold-rolled steel A B x 2 1 /6
x 6 in. long, with a hole bored at C to tit the center spindle and
one at B t6 fit the projecting post. The post was designed to
hold a diamond holder and was furnished with the machine, but
it had been broken.
A ^-in. hole was bored on the end to take a stud D in which
was set the diamond, setscrews holding the small stud in place,
so that it could be moved around and get even wear of the dia-
mond point.
This construction is solid and does not chatter at all. The
saving of time taken to put the new holder on and take it off
fully compensates for the change.
SECTION XII
BORING
PORTABLE CYLINDER-BORING MACHINE
FIGS. 165 and 166 show assembly and details of a boring ma-
chine that was designed to rebore both upright and horizontal
cylinders from 12 to 24 in. in diameter. For the larger bores a
head with longer arms is used to avoid excessive overhang of
the cutting tool.
FIG. 165 CYLINDER BORING MACHINE
The outfit is driven by a small electric motor fastened to a
pair of long skids upon which is placed sufficient weight of scrap
iron to hold it in place against the belt pull. For small cylin-
ders a small pulley on the motor is direct-connected by belt to a
large pulley on the shaft A, Fig. 165 ; and for the larger cylin-
221
222 AMERICAN MACHINIST SHOP NOTE BOOK
ders a countershaft is interposed on the skids with the motor to
secure the necessary reduction in speed.
The performance of the outfit has been very satisfactory.
The bevel gears make it possible to have the driving shaft in a
horizontal position regardless of the position of the cylinder.
The frame, gears and head are made of cast iron. The main
bearing in which the boring bar rotates is machined to fit the
bar, all other bearings being cored out large enough for babbitt
metal to be run. The large gear made especially for this job is
keyed to the bar with a hollow key, allowing the feed rod to pass
through it.
The support B, Fig. 166, was made as shown for use on an up-
right cylinder to fit the gland opening in the cylinder head; it
provides openings around its outer edge for the cuttings to drop
hrough. A leather washer with about a 5-in. outside diameter
a tight fit on the bar is slipped over the bar just above this
support to keep the cuttings out of the bearing.
The feed screw lies in the bar, and is connected to the boring
head by the key C and the half nut D, which fit into it ; the key
is held to the head by the two ^-in. capscrews tapped into the
end holes of the key.
The star wheel is a steel casting and is pinned to the feed rod,
the rod and wheel being held in place by the cap E. The spring
F is in turn fastened to this cap, its outer end resting on one of
the flats of the hub of the star wheel, when the star wheel points
are not in contact with the feed fingers G.
The spacing of the tapped holes in the part of frame H is such
that 1, 2, 3, 4 or 6 feed fingers may be used.
The tools, which are made from 1-in. square stock, are held in
the groove provided in the head 7, by the eyebolts J. This
groove is placed at an angle which provides leading rake on the
cutting tool without special forging. A backing-up screw sets
against the back ends of the cutting tool as shown.
For cylinders above a 12-in. diameter, the frame is blocked
out from the end of the cylinder to an extent equal to the thick-
ness of the cutting tool, to allow a cut to be taken to the extreme
end of the cylinder.
A small crank (not shown) is used to run the cutting head
along the bar by hand, and a long socket wrench is used to loosen
the nuts on the eye-bolts after the finishing cut is taken to avoid
223
224 AMERICAN MACHINIST SHOP NOTE BOOK
the scratch that the cutter would otherwise make in withdrawing
the head.
A BAR FOR BORING A CHAMBER
The bar shown in Fig. 167 was designed for recessing the cast-
ing A, the work being done in a boring machine with the casting
held in a special fixture. The diameter of the bored hole is 2%
in. at one end and 2^ in. at the other, with a chamber 2% in. in
diameter extending a distance of 6 1 A in. between them.
FIG. 167 BORING BAB FOR RECESSING
The tool block B is fitted to a slot in the bar and swings upon
the pin C. It bears upon a ledge within the slot at D, pro-
viding a solid locating stop which determines the diameter of the
recess after the tool E has been properly set by means of the
adjusting screws F and binding screw G.
The annular nut H bears upon the swinging tool block at /,
at which point the surface of the block conforms to the radius
of the bar.
As the nut is run back, the working point / travels down the
inclined surface of the block at J, allowing the spring K to
swing the block away from the bearing at D, thus moving the
point of the cutting tool toward the center of the bar.
In operation the bar is run into the work to the point where
the recessing is to commence, the machine is started and the
operator grasps the knurled portion of the nut, holding it against
BORING 225
the rotation of the bar. This causes the nut to advance along
the bar, the bearing point I traveling up the inclined surface J
of the tool block until the shoulder of the latter comes to rest
against the ledge Z>, and the cutter is then in the correct position
to bore the desired diameter.
A setting block by means of which the tool is properly set
before putting the bar in the work is shown at L.
BORING BAR FOR TORPEDO TUBES
Fig. 168 shows a boring bar that is used for boring torpedo
tubes, the sections of which are 18 ft. long and 21 in. in diameter.
The tolerance is 0.010 in.
9
FIG. 168 BAB FOB BOBING TOBPEDO TUBES
The bar is square, is 20 ft. long and turns between centers.
The ring A which holds the cutters slides back and forth on the
bar and is controlled by the screw shown at B. The gear at C
is secured on the tailstock center and meshes with gear D, which
is keyed to the screw. There are six cutters in this bar and the
time for boring one of these tubes is 12 hours.
BORING TAPER HOLES
Having occasion to bore some taper holes in work mounted on
a boring-machine table, the following method was used with satis-
factory results :
226 AMERICAN MACHINIST SHOP NOTE BOOK
As shown in Fig. 169, the casting A was secured to the table
with bolts, and an ordinary boring tool B set in the boring
spindle. Guide bar G was mounted in the horizontal plane of
the spindle and at the same angle with the spindle axis as the
required taper.
The end of the slide of the boring tool was equipped with a
hardened-steel adjustable button P with a spherical face.
Having the set-up arranged as noted, the gib screws 8 were
tightened enough that the slide of the boring tool would hardly
FIG. 169 ARBANGEMENT FOR BORING TAPER HOLES
move in the saddle. The guide bar was solidly bolted to the
table, and upon starting up and putting a slow feed on spindle,
the steel button P would hit the guide bar each revolution and
move the slide in slightly, thus changing the diameter of the cut.
The guide bar having been set to the proper taper, the result
was a similar taper hole in the part being machined.
It should be noted that this method will not produce a smooth
finish, but as in this case a taper bronze bushing was fitted, the
character of the cut was of no consequence.
BORING A 4-PT. HOLE IN AN 18-FT. SHIP CASTING
Some time ago we had a steel boom-deck casting for a dredge
come into the shop, which required boring out to allow for a
brass bushing to overcome the friction. The casting was in
halves, 18 ft. outside diameter with a bore of 4 ft. The bushing
was to be % in. thick and cut in two; each half to be held in
place with countersunk screws. The top was to be faced back
6 in. so as to allow for a brass ring, shown at Q, Fig. 170,
BORING
227
which was dove-tailed to make an even joint. This ring had an
outside diameter of 60 in. and an inside diameter of 48 in. and
% in. thick. The halves of the brass ring were also fastened in
place by means of countersunk screws.
To accomplish the work we turned down a piece of steel 7 in.
round and 3 ft. long as shown at B. We cut a key way 2 ft.
long to receive a key C, which fitted in a slot D of the bor-
ing-mill table E, shown at S. At the top end of the boring
bar we bored out a 3-in. hole 1^ in. deep, shown at T. We
then made a shank, F, to fit into the toolpost head, the bottom
FIG. 170 RIGGING USED
having a boss fitting neatly into the 3-in. hole of the boring bar.
Thus we were able to use the feed of the machine, as the boring
bar could revolve, being driven by the key C. We made a cast-
ing H of cast iron, bored and pressed on boring bar with two
setscrews; a slot in each end for the tool which was held in
place by a strap /. To face off we used a jackscrew J, while X
illustrates the manner in which jackscrew worked the tool out.
Being able to cut only one way it was necessary to use three dif-
ferent lengths of tools. Each half of the boom-deck casting was
jacked up from the floor and bolted to housings of machine.
Fig. 171 shows the work in progress, and Fig. 172 illustrates
the work successfully completed and ready for shipment j the
man in both illustrations shows comparative size.
FIG. 171 THE CASTING ON THE BORING MILL
FIG. 172 THE FINISHED CASTING
BORING
229
PRODUCTION CHUCK FOR A BORING MILL
The chuck shown in Fig. 173 was designed for a boring-
mill job. The piece to be machined is a cast bronze wormwheel,
the only machining being in the hole and two side faces. The
fixture as shown was built for rapid production. The sketch is
not to scale, but it illustrates the idea.
FIG. 173 BORING MILL CHUCK
The holding jaws work on a cam action tightened and re-
leased by a lever. The jaws are made to fit on the pitch diameter
of the wheel. The cut in this case is light, and of course the
heavier the cut the tighter the jaws wedge.
DRIVING-BOX CHUCK
In Fig. 174 is shown a specially designed chuck for holding
driving boxes upon a boring mill. For getting them in proper
center quickly, it has no equal. The base or bottom is a solid
cast-iron piece finished to 3%-iii. thickness. In addition, it has a
ring protruding l /2 in. This is l 1 /^ in. in width, and the outside
diameter of the ring is 35 in. ; inside diameter, 32 in. This ring
fits in a corresponding ring cut in the table of the boring mill.
j* y*-~n/i<
230
^
?o
^Mr~H^i I*
I I i s 1 *;
i *Wh
-b?
231
232 AMERICAN MACHINIST SHOP NOTE BOOK
The diameter of the boring-mill table is 4 ft. 6 in., and the
baseplate of the chuck is the same, thus presenting a neat and
uniform appearance. Fifteen screws like A secure the chuck to
the boring-mill table. The platen has in the center a hole 11H
in. in diameter, for cuttings to drop into and also to clear the
boring bar and tool. The detail B shows the main sliding jaws
of the chuck; there are two such and they are moved apart or
together up against the sides of the driving box, which are next
to the driving-box shoes. These two jaws are planed on the bot-
tom on two places 4 in. wide and 1 in. high. They are then
beveled at a 30-deg. angle to a width of 2 in., and these parts
are neatly fitted to corresponding slots planed in the bedplate,
as shown at C. One jaw is tapped right- and one left-hand, to
suit the screw.
One end of the screw D has 2^4 in. more of thread than the
other, and care must be taken to see that just this much of both
screws is screwed into the block having the right-hand thread.
Then the block having the left-hand thread is brought up against
threads on the other end of the screws ; both are turned, and the
jaws move in toward the center. Before this much is put in
place, two blocks, given as detail E, must be put in place, one
each in the slots marked F, which are planed in the table at
right angles to the jaw slots. One of these is tapped right- and
one left-hand, and at G is shown the type of screw that moves
them independently of each other.
The detail H represents a block that is dropped into place in
the slots 7. There are four of the blocks, but of course the two
jaws that fit on two long screws must all be put in before these
four blocks are put in place. Four slots, like J, are for clearance
in planing out the slots; and where the short screws are con-
cerned, the end forms a rest or backing for the shoulder near the
end of the screws.
The two jaw screws are connected by gears, as illustrated, so
that when the center gear is turned, both screws turn in unison
in the same direction. When all the gears are in place, a Vs-in.
wrought-iron plate with beveled edges is fastened over them as
a gear guard to keep dirt out and also to keep a man's fingers
out, a feature that is also important.
At L are shown details of one of the two blocks that are re-
movable in orcler to put the driving box on or off. The base, or
BORING
233
plate, is of cast iron; the jaws are steel castings, while the gears
are of soft or axle steel, as are also the pins.
The two small blocks shown are for adjusting the box along
the large jaw faces, in order to bore more or less out of the part
that rests on the axle. One of these blocks has to be taken out
when the box is put on the machine or removed therefrom. That
operation is easy, owing to the block being shorter than the part
that moves it in against the box. When all jaws and setscrews
are tightened up, it would take about as much of a lift to loosen
the box as would be necessary to pull the machine off its founda-
tion.
CENTERING WORK WITH GRADUATED WEDGES
For centering circular work on the vertical boring-mill table
we have developed a method that effects a marked saving of time
over the usual chucking and truing up with an indicator clamped
in the toolpost. The ring gear R, Fig. 175, is clamped to the
FIG. 175 GRADUATED WEDGES FOR CENTERING WORK
boring-mill table by four toe clamps C. Four dowels l 1 ^ in. in
diameter are located equidistant from the center of the boring-
mill table. Four wedges graduated in quarter-inches, as shown,
are driven in between the ring and gear and the dowels. When
the same marks line up with the centers of the dowels on oppo-
site sides, it is evident that the casting is correctly centered,
234 AMERICAN MACHINIST SHOP NOTE BOOK
Both dowels and wedges are hardened so that they are compara-
tively long lived. The centers of the dowel-pin holes are lo-
cated by clamping a scriber in the toolpost, locating it the cor-
rect distance from the center, so that when the table is rotated,
a circle is drawn on its face. When an air-operated jib crane is
used, swinging directly over the table, the time for clamping
and centering rarely exceeds two minutes, which is a saving of
700 per cent, over former methods.
SECTION XIII
GEARING
DECIMAL-EQUIVALENT TABLE USEFUL IN GEAR
WORK
WHEN laying out gearing it is frequently desirable to consult
handbooks for tables giving the decimal equivalents of common
fractions. These tables of course, are of value if the diametral
pitch of the gears under consideration corresponds to the de-
nominators of fractions shown in the tables; but this coinci-
dence does not always favor the person who makes the calcula-
tion. A complete table of decimal equivalents for those frac-
tions which would be of greatest help, has long been desired, and
as the center distances and diameters of gears are generally
given in decimals, the need for such a table is obvious.
Consider for example, two spur gears of 22 diametral pitch,
having 36 and 42 teeth: by dividing the sum of the teeth in
both gears by twice the diametral pitch, we find the center dis-
tance to be (36 + 42) -=- (2 X 22) = 78 -i- 44 = ! 34 /44 or 1%.
From the accompanying table it will be found that % equals
0.7727, hence the center distance is 1.7727 inch.
If the pitch diameter of some gear is to be found for ex-
ample a gear of 22 diametral pitch, having 36 teeth we divide
the number of teeth by the diametral pitch, with the result
36 -f- 22 = ! 14 /2. From the table 1 %2 = 0.6364. Hence the
pitch diameter of the gear equals 1.6364 in., while the outside
diameter equals pitch diameter plus twice the addendum, thus:
! 14 / 2 + %2 = I 10 /d = 1.7273 inch.
When the outside diameter of the same gear is required,
without knowing the pitch diameter, we add two to the number
of teeth and divide the sum by the diametral pitch, giving
( 2 + 36 ) -f- 22 = 38 -=- 22 = ! 16 /22. According to the table
!%2 = 0.7273. Hence the outside diameter of the above gear
equals 1.7273 inch.
235
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GEARING
237
I have found it a most useful table when calculating gear
trains.
INTERMITTENT WORM GEAR
A worm gear used in connection with an automatic wire-
working machine seems to offer great possibilities and adapta-
bility in connection with automatic-machine design.
Fig. 177 shows sectional and end view of a three-piece inter-
mittent gear, each section of which is intermittent and in which
FIG. 177 THE INTERMITTENT WORM GEAR
the length of dwell can be regulated to perform the required
function. A shows the worm ; B, C and D are three sections that
constitute a full worm gear ; spaces L, M and N show teeth of the
gear cut away to produce the dwell ; H, I and J show a crank-
shaft and eccentric cams to produce the necessary mechanical
movements. These, of course, may be designed to meet require-
ments. At K are housings of the machine. Section C of the
worm is keyed to the shaft. This section has adjustable stops on
either side, marked E, movable in T-slots G. They are adjusted
through openings in the sidewalls of B and Z), which have the
stops F. These stops may also be made adjustable.
Each section of the worm makes a full revolution and a dwell,
the length of time depending upon the relation of the stops E
and F to each other. The machine in question was used to weave
wire fence, which, while it cannot be called fine work ? is rather
exacting.
238 AMERICAN MACHINIST SHOP NOTE BOOK
FORMULA FOR OBTAINING CUTTING ANGLE OF
HELICAL GEARS
It is often required to replace spur gears with helical gears
where the pitch diameter and number of teeth cannot be changed,
as in speed boxes, etc. In this case a finer pitch cutter must be
used, and the "cutting angle made such as to give the correct
proportion of tooth and space. While working out a problem
of this kind it occurred to me that a shorter way than by cir-
cumferential pitch could be used. For example, given a change
speed box with 6 diametral pitch spur gears, to replace them
with helical gears of 6^ diametral pitch. 6 -f- 6.5 = 0.9230 =
A
cos 22 30', which is the cutting angle. The formula is =
B
cos C; where A is the diametral pitch of the spur gear, B is the
diametral pitch of the helical gear and C is the cutting angle of
the helical gear.
SECTION XIV
SCREW MACHINE
MACHINING A 5%-IN. PISTON ON A 3^-IN.
GRIDLEY AUTOMATIC
NOT having a sufficient quantity of this work to warrant a spe-
cial machine, and yet desiring to take advantage of the lower
operating cost of the automatic, we designed the fixture here
described and shown in Fig. 178 to accomplish the third opera-
tion which includes facing, turning and chamfering a 5%-in.
gas-engine piston and cutting the oil and ring grooves.
FIG. 178 FIXTURE FOB TURNING PISTONS
It is not possible to show all the tools in the picture. The
forming-tool holder carries the tools for facing the end, cham-
fering, cutting the oil grooves and roughing the ring grooves to
within %4 in. of size. The rear block carries the tools for
finishing the grooves to size.
239
240 AMERICAN MACHINIST SHOP NOTE BOOK
The turning tool is carried in a 3-in. round cold-rolled steel
bar which is operated by a fixture attached to the turret. The
forward end of this bar slides in a bearing provided by a casting
which is bolted to the head of the machine, and is cut away as
shown to clear the main bearing. The actual bearing for this
pilot bar is made by pouring babbitt around it after assembling.
There are but two cams on the cam drum, one for the forward
movement and one for the return. The turret is not indexed.
K...H. s/23/iTTIME STUDY r * 1 ""
NAME SHAFT (~*) 8C8D5 (^) MAT - M.C.
SYMBOL jj P32CENO. g23 OPER. NO. IT!
OPERATION r^jy. 4 p IA |-. ? c,R CHIim FAGS JE-'CX F.OUHD C03:.' :t R
TYPE V i S C4-" X 26 n OPERATOR jTorum MACH.NO. 2G6
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DETAIL OPERATIONS
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236
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Index-Neok 3 .diam.--Gn*e-Indo
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1 7-8" Machine steel
Bars 16* long
Prepare end 3 '
Itoohine tine 8.93
U/indle 717
Stock Eemoved 2.3/
Actual Floor to Floor Tine
16
in
FIG. 179 TIME STUDY SHEET
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241
242 AMERICAN MACHINIST SHOP NOTE BOOK
As the tools are all working at once the turning time covers the
time of the operation.
The spindle speed is 48 r.p.m. The turning tool is No. 3
stellite, all the others being high-speed steel. The countershaft
pulleys are arranged to use two 2%-in. double belts for driving.
The work was formerly done on hand-operated screw ma-
chines with a working time of 1 hour for the operation. The
time consumed by this method is 12 min., and four machines
are handled by one operator.
TIME STUDIES IN SCREW-MACHINE PRACTICE
Time-study articles and charts relative to the output that can
be reasonably expected from various machine tools are of great
value to manufacturers of machinery. The chart illustrated in
Fig. 179 is the result of time-study work in the screw-machine
department of the Gisholt Machine Co., and is one of many
compiled from a great number of time studies having corre-
sponding speeds and feeds. Considerable care was required in
laying out these charts that they might embrace as many differ-
ent parts as possible, thereby assisting the rate setters in locat-
ing the proper time studies to follow.
If necessary, the chart may be used without the time studies,
but to set a rate that is just to the operator, the hand-feed and
handling time is required. The chart is self-explanatory and
when used in conjunction with the time study illustrated, will
aid in setting accurate rates. The work from which these charts
were compiled was the product of hand-operated turret ma-
chines, which were belt driven through three-speed counter-
shafts.
SLOTTING AND SHAPING IN THE AUTOMATIC
SCREW MACHINE
The tools described, which are used as attachments for Brown
& Sharpe automatic screw machines, were designed to include
second, or hand, operations with the automatic machining of the
parts shown.
At A y Fig. 181, is illustrated a stud that is completed in a No.
Brown & Sharpe automatic screw machine from %-in. round
SCREW MACHINE
243
brass. The slotting was formerly done in a separate operation
after being drilled in the drilling machine to remove stock. To
shape this slot in the automatic screw machine, the spindle is
stopped with a standard attachment, and stock is removed for
slotting by drilling two holes with a special combination cross-
drill and cuttirig-off attachment.
The special shaping-tool holder B is mounted in the turret and
carries the bushing 0, which supports the stem while shaping
the slot. The shaping-tool holder D is a square plunger and is
retained in the holder B by the plate E and the retainer screw
F. The eccentric G is driven by the pulley shown mounted on
FIG. 181 ^
FIG. 183
FIGS. 181, 182 AND 183 SLOTTING AND SHAPING ATTACHMENT
the r*ear cross-slide giving motion to the slotting plunger D
and the cutter H. A cross-section at / shows the spring plung-
ers that keep the toolholder in contact with the eccentric G.
In operation the stem is turned with a box tool, the spindle
stopped, and a hole cross-drilled to remove stock for one end of
the slot ; the drill is withdrawn and the stock fed forward and a
second hole cross-drilled to remove stock for the other end of the
slot. The 'cross-drill is then withdrawn, and the turret is in-
dexed and advanced to bring the special shaping tool into line
with one of the cross-drilled holes. It is caused to remain in
this position by a dwell on the lead cam, while the rear cross-
slide advances sufficiently for the eccentric to push the cutter
through the work. The throw of the eccentric is equal to the
diameter of the stem of the work plus clearance, and the speed
244 AMERICAN MACHINIST SHOP NOTE BOOK
of the pulley is sufficient to give the cutter rapid motion, while
the lead cam causes the turret to advance and then slowly
withdraw, thus giving the cutter a fine feed to complete the
length of the slot. The width of the cutter is the same as the
width of the slot.
The cams are similar in design to those for operating swing or
undercutting tools. After the work is completed, the lead cam
causes the turret to dwell until the rear cross-slide has with-
drawn sufficiently for the shaping tool to clear the work, at
which point it has ceased operating and the turret may then be
indexed. The fed of the lead cam for this shaping operation is
0.001 in.
Other parts that were successfully completed, including shap-
ing cuts, are shown in Fig. 182. The economy of completing
these parts in one setting is obvious. The piece A is made in a
No. 2 Brown & Sharpe automatic turret forming machine from
0.750-in. soft machinery steel, extruded stock, the shape being
the same as that shown. After the groove has been turned, the
spindle is stopped with the flat side of the stock up. The groove
is then completed by a shaping operation similar to that de-
scribed above.
For such light cuts in soft .brass and machinery steel as
shown at B, the special shaping tool C may be used. This tool
is self-contained, mounted in the turret and driven by the high-
speed drilling attachment. The revolving shaft D carries a
thrust collar E and the cam slot F, which through the roller at
G give the bushing H and the cutter / a reciprocating motion.
A hole at J provides a means of assembling the taper pin in the
thrust collar, and the hole K provides for assembling the hexa-
gon nut L on the roller G. A rectangular key is shown at M,
and the straight slot N opening into the cam cut provides a
means of assembling the shaft D into the bushing H after G has
been assembled. This slot is located radially on the cam slot at
the beginning of the return stroke, so as not to interfere with the
roller G.
For machining heavier cuts than those shown in Fig. 182, the
shaping tool, Fig. 183, may be used. The construction of the
tool differs from that in Fig. 181 only in the application of the
cutter, which is located longitudinally instead of transversely,
and has clearance so it will cut on end.
SCREW MACHINE
245
GUARD FOR DEFLECTING COMPOUND
Manufacturers who are engaged in the production of muni-
tions on 4^4-in. single-spindle Gridley automatics utilizing cool-
ing compound and individual circulating systems will find that
guards similar to the one shown are great time savers.
I know of one battery of 52 machines running 24 hours a
day which is using these guards, and since their adoption no
time has been lost due to grinding the rotating stuffing-box to
a better fit.
FIGS. 184 GUARD FOB DEFLECTING COMPOUND
Fig. 184 shows clearly how this hood is laid out on sheet
metal. When cut out it is rolled into a frustum of a cone and
the lap riveted or soldered. The hood is slipped over the draw-
bar, where it projects through the turret. The four hose leads
must be disconnected and then screwed in place through the
four holes in the guard. This is all that is necessary to hold the
hood in place, and there will be no more streams of compound
shooting onto the floor.
TOOL FOR REMOVING BURRS FROM JAM NUTS
Recently a batch of %-in. jam nuts that had been produced on
an automatic screw machine had such a burr on one side that it
interfered greatly with the assembly of the apparatus of which
they formed a part. It was decided to remove this burr with
246 AMERICAN MACHINIST SHOP NOTE BOOK
the hand screw machine, and the little tool shown in Fig. 185
was designed, which helped to do the trick.
The tool consists of three essential parts, a slotted sliding col-
lar A, fitted to slide on the stem of the stud B, being held in
normal position against the stop pin C by the spring D.
The tool is carried in one station of the turret and a suitable
countersink in another. The purpose of the tool is to place the
jam nut in the collet while the machine is running. This is
accomplished by first placing the jam nut in the slot E at the
FIG. 185 TOOL FOR REMOVING BURRS FROM JAM NUTS
forward end of the tool. The turret is then moved forward until
the collar comes into contact with the collet and the continued
forward movement of the turret permits the stem of the stud to
press the jam nut into the collet which is next quickly closed.
A stationary rod is secured inside of the spindle to prevent
the jam nut entering too far. The countersink is next moved up
and the burr removed. The rod also acts as an ejector, for the
moment the collet is released the jam nut is ejected. With this
equipment a girl can burr about seven hundred nuts per hour.
SENSITIVE TAP AND DIE HOLDER
A job came along a while ago that did not seem to fit our
smallest turret lathe, and we were somewhat worried as to how
it was to be done without undue breakage of taps.
The piece is shown in Fig. 186, and you will agree that the
tapping of the No. 6-32 hole to the bottom in tobin bronze
does not look real good for as heavy a machine as the No.
4 Bardons & Oliver, however we made the holder shown in Fig.
187. This worked so well that it has been used for other similar
SCREW MACHINE
247
jobs, like drilling and threading small parts on heavy turret
machines.
In operation the knurled sleeve with the tap, drill or die se-
cured in a suitable bushing is held lightly in the bare hand and
I y/7 IV
^2-Jhreads
|(SJ
JL
TOB1N BRONZE
(Jail over)
FIG. 186 THE WORK
FIG. 187 THE TAPHOLDEB
fed up against the work. When the hole is tapped to the bottom
the sleeve turns around on the shank. This gives one ample time
to reverse the machine and acts as a safety device to prevent
breakage.
THREAD ROLLING IN THE AUTOMATIC SCREW
MACHINE
My experience is confined entirely to brass, and chiefly to fine
threads that were produced entirely by the roll, without any
previous threading. The work was threaded on one end with a
male thread and on the other with either a male or a female
248 AMERICAN MACHINIST SHOP NOTE BOOK
thread. The rolling process was resorted to on the male-thread
end, to avoid a second handling.
It has always seemed to me that theoretically the production
of threads by this method should be impossible, and for this
reason : The angle of the top of any thread is always less than
the angle of the bottom, so that no matter what relation the
diameter of the roll bears to the diameter of the work, it is im-
possible to make the two threads track or match at more than
one point in the depth of the thread.
FIG. 188 FIXTURE, DRILL JIG AND ROLL HOLDER
This inevitably results in a sidewise crowding or strain be-
tween the threads of the roll and the work. Conditions are fur-
ther aggravated by the fact that it is the top or weakest part of
the thread roll that must sink the deepest into the work and form
the bottom or strongest part of the threacj on the work.
We were able to obtain little definite information as to the
proportions of rolls, but the rule most favored seems to be to
consider the pitch diameter of the work and to make the pitch
diameter of the roll a multiple of it, adding the single depth of
thread. The rolls that we made were two, three or four times the
size of the work and correspondingly threaded double, triple or
SCREW MACHINE 249
quadruple, as the case might be, while the roll must be cut left
hand to produce right-hand results.
This method was followed for a number of years, but was
finally changed to rolls in which the top of the thread had the
same helical angle as the bottom of the thread on work, so as to
decrease as much as possible the sidewise crowding at the top of
the roll thread, transferring it to the base of the thread. This
was an improvement.
It is exceedingly difficult to get a roll tempered so that it will
be hard enough to stand up to the work and soft enough not to
break. We had no hardening refinements beyond a lead bath
(no pyrometer) and an oil tempering bath, and we did not grind
the rolls after hardening.
With the utmost care it seemed impossible to get any two
of a lot of rolls to produce the same results as to length of
service. We tried many brands and grades, but obtained
the best results when we used Firth's Best Tool Steel, No. 4
temper.
The first, and for years the only, way in which rolls were used
was to hold them in a rigid holder on the cross-slide at the same
height as the work and, after the work has been formed, advance
the roll at high speed to its full depth and as quickly withdraw
it, allowing it to remain in contact 'with the work for only an
instant.
A longer dwell on the high point of the cam would result in
the side motion of the roll, previously mentioned, and then the
whole thread would be stripped from the work, leaving the root
diameter.
When we were so fortunate as to get a roll "just right" we
could produce as high as 100,000 pieces with it before it wore
out, but the process was very hard on the front spindle boxes,
wearing them oblong in a comparatively short time, due to the
sharp rise of the cam and resulting blow when roll and work
came in contact.
Eventually we got some new Brown & Sharpe automatics and
tried to develop a process that would give less pressure on the
front bearing. We worked along the line of a holder in which
could be two rolls capable of being adjusted to and from each
other and clamped in position, the holder carrying the two rolls
to have a slight oscillation to allow the rolls to center themselves
250 AMERICAN MACHINIST SHOP NOTE BOOK
on the work. The rolls were to straddle the work, one passing
over it and the other under.
At the bottom in Fig. 188 is given an idea of the first fixture
made. It consisted of the base A, which was bolted to the cross-
slide, and B, which held the rolls and had a limited movement on
the pin C. As will be seen, the upper roll was carried in a fork
which was tongued and grooved vertically to the part J5, clamped
by the nut D and held up to the work by the setscrew, as shown.
The lower roll fitted the holder closely, but the upper one was
free to move sideways on its pin about %2 in., with the idea that
it would crowd into the thread made by the lower roll as soon as
a thread began to be formed and by dividing the work between
two rolls would tend to more accurate work and longer service
from the rolls.
Curiously enough it worked from the start for several thou-
sand pieces, but the second time we attempted to set it up for a
thread-rolling job it would not work at all.
A month or so later we tried it again, with the same result.
As extended trial failed to disclose any reason, we gave it up as
a failure.
The fixture just described was made as strong as the rather
limited space on the cross-slide of a No. B. & S. would permit,
but was quite plainly not rigid enough to resist the side thrust
of the rolls. At about this stage it became desirable to make this
class of work on multiple spindle machines, where we had pre-
viously done so, using the method first described that is, feed-
ing a roll directly against the side of the work. It had worked
very well when the machines were new, but the spindles and
bearings had become worn, some more than others, and this
made it impossible to secure work anywhere near the required
limits from the different spindles, so we fell back on the double-
roll idea, but with the following changes:
Having plenty of room on the cross-slide, we made a holder of
machine steel that was many times stronger than the first one;
in fact it was very heavy, but trial showed that it was none too
strong. It is my recollection that the pin on which the oscillat-
ing member moved was about Ik in. in diameter and everything
else in proportion.
We also abandoned the upper thead roll for a plain roll, which
the nature of the work permitted. This roll did not, of course,
SCREW MACHINE 251
take bearing on the thread but on each side of it, and served to
hold the thread roll up to the work. This arrangement worked
after a fashion, but did not meet expectations.
We next altered the holder to accommodate two threaded rolls,
which were keyed to their spindles and these in turn geared to-
gether so that the two rolls were always in a fixed relation to
each other.
The gears were inclosed in a tight case to keep out dirt, and
by means of an adjustable idler between them it was possible to
get a limited amount of adjustment between the rolls. This
proved the best combination and produced better work than any
of the others, with longer life to the rolls.
The threads we were to produce were 27 per inch, and the
rolls were made with a quadruple thread, 6% threads per inch
being cut several at a time on a gang arbor.
After chasing, they were screwed into the drill jig, in the
upper left hand corner of Fig. 188, and a hole drilled. This
hole located the thread always in the same place on the roll-
holder bushing, to the right, and these bushings in turn were
keyed to the geared spindles, which were made in one piece and
rotated in hardened bushings.
In fitting up the holder we were careful to get the keys located
in these two spindles so that the same roll could be placed either
on the top or bottom spindle and be in correct relation to the
other roll. The gears were marked in their proper timing to
avoid trouble when replacing them in the holder.
This would seem like an expensive thing to make. However,
I believe the results will justify it wherever such work must be
done in large quantities, for it will produce more accurate work,
will do this on a multiple spindle machine with worn bearings,
and the work being divided between two rolls, which are held in
positive relation to each other, the rolls will last longer.
These advantages will surely appeal to any one who has been
up against this proposition.
HOLLOW SETSCREW AS AN ''ADAPTER"
Trouble was experienced in tightening the screw that holds
the rolls in the holder of the roller back rests on our Gridley
automatic screw machines. It is necessary for this screw to be
252 AMERICAN MACHINIST SHOP NOTE BOOK
placed in the curved portion of the tool slide. This makes it
almost impossible to use a wrench on the screw, which must be
securely tightened.
I took an ordinary blank hollow setscrew, drilled one end, and
tapped it according to the size of the screw. I then inserted the
regular bent hollow-setscrew wrench. In this manner the screw
was tightened without any inconvenience.
This scheme is equally useful in any place where it is difficult
to use an ordinary wrench. It is a device that can easily be
secured in any machine shop, as all that is required is a piece of
round steel of the proper length to allow for the necessary depth
of the tapped hole and the insertion of the wrench at the oppo-
site end.
SECTION XV
SHOP TOOLS, APPLIANCES AND
EXPEDIENTS
CONSERVATION VS. EFFICIENCY
IT has always been the writer 's idea, and I suppose the idea of
ninety-nine out of a hundred other persons, that conservation
and efficiency are synonymous as applied to industrial plants.
A few examples which have recently come to the attention of
the writer have now led him to think otherwise. One of the
cases that comes to mind is metal wheelbarrows. In the plant
in mind there are not a great many of these in use, and when
some part breaks it is found cheaper to buy a new barrow than
to repair the old one. Were there more in use, it would un-
doubtedly pay to repair them, but a man assigned to repair a
single barrow will waste so much time thinking about starting
and in puttering around that repairing is not a paying proposi-
tion. Efficiency in this case counsels, buy a new one; conserva-
tion would repair the old. Another case where a difference in
these word meanings is illustrated is in the separation of oil from
chips. The plant did not have a great many oily chips, but a
man with a small separator was employed to take care of what
there were. Careful calculation showed that the man's wages
were about twice the value of the oil he recovered. Conservation
all right, but not efficiency! Had the amount of chips been
great enough to warrant the purchase of a goodly sized sepa-
rator, the case, of course, would have been entirely different.
Another instance which illustrates this point is that of sepa-
rating coke or coal from the ashes of a boiler plant. In one
case of a stoker-driven boiler, it was noticed there was consider-
able coal burned to coke, pulled out when cleaning fires. A
laborer getting $2.50 per day was put to work picking out the
coke and got about 400 Ib. per day. This, of course, did not
pay his wages and the work was stopped ; yet, when we think of
253
254 AMERICAN MACHINIST SHOP NOTE BOOK
the present shortage of coal it seems a pity to let even this
amount go to waste.
A plant in the same vicinity has a man pick over the ashes
and record the weight of coal recovered during each shift.
This has a good effect on the fireman, and while the picker does
not earn his wages in coal recovered, he earns them indirectly
in the coal saved by more care on the part of the fireman.
There are doubtless many instances much more important
than the trivial ones mentioned, and it would seem that in these
times of shortage of materials, it might be loyal to sacrifice effi-
ciency if necessary, for the sake of conservation.
IMPROVED DRIP CAN FOR HANGERS
The usual drip can on a hanger is either a cast-iron cup or an
old tin can. In a certain shop where new machinery is being
installed with a view to saving all the time and material pos-
sible, several galvanized cans were made which are as long as the
hanger bearing, and to the bottom of these cans a screw cap was
added.
Any oil which drops of course goes into the can, and after a
time the oiler merely unscrews the cap and saves every drop of
oil, which is strained and used again.
METHOD OF RECLAIMING WASTE
The high cost of waste and rags used throughout the machine
shop made it necessary to cast about for means to reduce our
charges for this material, so we devised a washing arrangement,
which was made up by our engineer out of some old pipe fittings.
As shown in Fig. 189, a piece of 12-in. pipe was arranged
with companion flanges on each end, a steam inlet in the side,
and a drain at the bottom. A screen was then placed in the
pipe about 4 in. above the steam inlet. The oily waste was
placed in the washer above the screen by removing the com-
panion flange, and then the whole mass was boiled by turning in
the live steam, the condensation dripping down through the
waste and carrying the oil and dirt off through the blow-
off valve. While this crude washing did not turn out per-
fectly clean waste, it nevertheless took out such a large percent-
SHOP TOOLS, APPLIANCES AND EXPEDIENTS 255
age of the oil, grit and dirt that the waste could be used for
practically all purposes. The expenditure for new waste was
thereby cut down between one-half and one-third each month.
FIG. 189 APPAEATUS FOR RECLAIMING WASTE
INSTALLING OVERHEAD APPARATUS REDUCES
OVERHEAD EXPENSE
The small machine-manufacturing plant must use considerable
ingenuity to secure the advantages that come to the large shop
through quantity manufacture, without incurring too heavy
charges. It is a comparatively simple matter in the large shop
with a great volume of standardized work to arrange machine
equipment so that pieces proceed from operation to operation
with the least amount of handling and expense.
Fig. 190 shows an arrangement of millers by which the
central swinging jig crane A permits the handling of work
from one machine to another, all three millers B, C and D tak-
ing care of individual operations. One man operates these
three machines, on which the tool and fixture set-up is perma-
nent.
256 AMERICAN MACHINIST SHOP NOTE BOOK
Another feature worthy of note in this illustration is the ar-
rangement of overhead beams shown at E, which allows great
flexibility in arranging countershafts. These beams consist of
FIG. 190 CRANE ARRANGEMENT
two angle irons mounted back to back, with a space between them
to receive bolts and cast-iron spacing blocks riveted in at in-
tervals.
ECONOMY IN HACKSAW BLADES
For odd work I like a machine or two to spare, so as to let
the blade jog through without much regard to time. This
saves blades. The operator can easily push things on a rush
job where the cost of a blade is as nothing compared to getting
the work out quickly.
For repetition work I like a carefully selected machine of
suitable size and power and a blade thin yet strong enough to
carry sufficient weight to wear itself out on its later cuts. I fix
a position for the weight which on a blade 's first cut will not tear
SHOP TOOLS, APPLIANCES AND EXPEDIENTS 257
out or destroy the sharp edges of the teeth ; also, a cutting time
that must not be exceeded per piece. The first cut takes less
than this maximum time, and the operator increases the pres-
sure as the time taken gets longer. A blade that is too thin
breaks before being worn out, and one that is too thick takes a
longer time before being worn out. An adjustment of the
weight position and alteration of the time allowance will soon
discover the best average conditions for any make of blade on
standard work on any machine.
Most of the good brands of saws give satisfactory results if
they are studied and conditions arranged to suit them. These
conditions are very simply determined and are, I think, in actual
operation more frequently than some writers believe.
REPAIRING BELT SHIFTER
The belt shifters of a planer that had been in use for a long
time became so badly worn that it was necessary either to repair
them or replace them with new ones. They were repaired in the
following manner : Taper, dovetailed grooves %6 in. deep and 2
FIG. 191 STEEL INSERTS IN SHIFTER
in. long were filed at the worn places, pieces of hardened steel
were fitted into the grooves, and the edges were rounded to con-
form with the shape of the shifter. This repair was made three
years ago, and the plates do not show the slightest wear.
AIR-HOIST PISTON PACKING
Fig. 192 shows a method of making an air-hoist piston and
cup leather that will give good service. I have made many
such for use in an iron foundry where the hoists are used
258 AMERICAN MACHINIST SHOP NOTE BOOK
to handle ladles of iron while " pouring off" machine floors.
This service requires them to hold steadily at any height
needed and subjects the hoist to considerable heat. The ring
of square hemp packing A serves as a swab and distributes any
heavy oil used to lubricate the piston and cylinder.
To assemble, slide the cup leather B into place, then the
slashed sheet-iron disk C, and then the follow plate D, and
FIG. 192 AIB HOIST PISTON PACKING
tighten all with the cap screws. The %-in. spring rings E
should stand open % in. when spread and the ends butt when
closed. Slip these into the follow-plate groove behind the sheet-
iron disk and they will keep the edge of the cup leather tight
against the cylinder wall all around, and the air pressure will
finish the job. The piston should then slip in easily.
SECURING CRANE HOOKS
Trouble is often experienced in the foundry by the loosening
md unscrewing of the nuts that support the hooks of cranes and
SHOP TOOLS, APPLIANCES AND EXPEDIENTS 259
air hoists. Owing to the heat, dust and damp sand, the bearing
surfaces become dry and rusty in spite of frequent oiling. I
have known nuts to unscrew and come off entirely under the
ordinary swiveling back and forth of the hook with its load,
even though the nut had a %-in. pin passing entirely through it
FIG. 193 SECUBING CBANE HOOKS
and the hook stem. A washer of annealed tool steel, faced true
on both sides and with a square hole to fit snugly on the squared
end of the piston rod or hook stem, as shown, will stop the diffi-
culty. Press the washer to its place with the nut, and pin the
latter with a small pin, as shown in Fig. 193, to prevent loosen-
ing by jarring.
POWER DEVICE FOR "SPOTTING-IN" PARTS
When scraping in heavy parts of machine tools or bearings, it
is often unhandy to keep a gang of helpers to aid a skilled
mechanic to move the parts while "spotting" the work for
scraping. In many places conditions are such that no special
devices can be used for doing this work, but in shops producing
large quantities of similar pieces such apparatus can sometimes
readily be designed, or some stock device be placed upon this
special job, with the result that only the skilled mechanic is
needed upon the work, leaving the helpers free for other duties.
Such a device was recently seen by the writer in the shops of
the Blanchard Machine Co., Cambridge, Mass. The head of
this company's heavy, high-powered vertical surface grinder
carries an electric motor built upon the shaft that drives the
grinding wheel, making a compact and neat design, but requiring
close, accurate, scraped fits upon its guides, While the motor
260 AMERICAN MACHINIST SHOP NOTE BOOK
is capable of exerting over 30 hp., still the movements of the
head must be accurately controlled, as the limits of accuracy in
the output are often less than 0.0002 inch.
The gibs for these guides are scraped in the following man-
ner: The column A upon which the vertical head B has its
sliding fit is laid down horizontally, with the head in place. To
the head is attached the piston rod C of an ordinary stock air
hoist Z>, the cylinder being attached to the frame E of the ma-
chine. When the parts to be fitted are properly coated with
red lead and the gibs fastened in their proper positions, the
scraper hand merely operates the air-control lever F of the
FIG. 194 POWER SPOTTING DEVICE
hoist. When the head slides forward to the predetermined point
the operator reverses the hoist, bringing the head back to the
initial point. As many strokes as may be required having been
completed, the hoist is stopped, the gibs removed and examined
and, if necessary, scraped and again marked as before.
It is simply a case of a standard device being put to a new
use with good results. There is no pulling and hauling of
heavy parts by a high-priced mechanic, nor any need to keep a
gang of helpers within call. The work is done rapidly and bet-
ter than by hand, the gibs can be set tighter, and as the power
permits steady positive movement of the fitted parts, it is likely
that more precise and positive spotting is secured, thus permit-
ting work to be scraped with fewer trials. A similar device is
in use at the shops of the Landis Tool Co., Waynesboro, Pa., and
is giving satisfaction.
SHOP TOOLS, APPLIANCES AND EXPEDIENTS 261
IMPROVED HALF-ROUND TAPER REAMER
Having a hurry job for a taper reamer and no fluted reamer
of the size required, I concluded to try the old time-honored
half-round, but before I started to cut it down to the center line
FIG. 195 HALF-BOUND TAPER REAMER
I commenced to think and reason if there was not some bet-
ter way than cutting the metal away to the center line, which
renders this tool so fragile.
Instead of reducing to the center line, after carefully drawing
two center lines, I only cut slightly over one-quarter, as shown
at A in Fig. 195. I then carefully backed off the one-quarter
portion B at the back of the reamer. I then hardened and
ground it on a small wheel to give a slightly concaved cut,
stoned it, and was surprised to see the result. It is a fast-cut-
ting tool and the only requisite is to keep the concaved cutting
edge sharp.
HOLDER FOR COUNTERSUNK HEAD BOLTS
The device shown in Fig. 196 is for holding % x 2 1 /-in. coun-
tersunk head bolts while the thread is being cut in the bolt cut-
ter. The holder, which is made of machine steel, case hardened,
is securely clamped in the jaws of the bolt cutter with the slot in
a vertical position, and extending ahead of the jaws. A bolt is
then inserted into the slot, either from the top or the bottom,
and pushed forward into the countersink.
The hardened key A is then put into the slot until the ring B
rests on the holder. This brings the knife-edge of the key into
line with the bolt head.
The screw C at the rear is then tightened, causing the knife-
edge of the key to sink into the head of the bolt and preventing
it from turning. To remove the bolt, the screw is loosened and
262 AMERICAN MACHINIST SHOP NOTE BOOK
the key lifted out; when the bolt is pushed back, it will drop
out.
TAPPING BRONZE FEED NUTS
Recently we had ten small bronze feed nuts to tap for a 10 x
32 U. S. thread. These nuts were to be used in the construction
of a precision graduating machine, and the threads were re-
quired to be accurate and smooth.
At first we tried an ordinary 10 x 32 tap, but, although this
tap was ground especially for this job, this method had to be
abandoned before even one of the nuts was tapped, for the
FIG. 196 HOLDER FOB COUNTERSUNK HEAD BOLTS
bronze would stick to the tap and clog between the teeth, tearing
the threads. I nearly spoiled the nut with this tap.
Next we tried grinding a very long lead, or chamfer, on the
tap, leaving about three threads full size ; the flutes were under-
cut, to give a hook to the cutting edge of the lead. This also
failed, due to the bronze sticking to the lead, just as it stuck to
the teeth of the first tap.
At the third try we found the way to tap these bronze nuts
accurately, smoothly, and what was equally important to us,
quickly. We also avoided the annoying tap breakage, usually
incidental to tapping bronze. Three taps were used, but of dif-
ferent sizes and the same pitch. First we followed the drill with
an 8 x 32 tap. This took a light cut, and the metal did not stick
SHOP TOOLS, APPLIANCES AND EXPEDIENTS 263
to the tap. We followed this tap with a %6 x 32, which cut the
thread deeper and, like the 8 x 32, cut easily and freely.
Lastly, the sizing tap, a 10 x 32, was put through, bringing
the threads to size. Of these three taps, not one "picked up"
metal. They all cut freely and produced a perfectly true and
smooth thread. Nor was there, at any time, the slightest dan-
ger of a tap breaking. It seems, in tapping a tough, clinging
metal, the best all-around method is to use taps of different diam-
eters, but the same pitch of course; the smaller taps are then
used to sort of rough out the threads, while the larger taps
gradually bring the thread to size and produce the finish.
PORTABLE PRONY BRAKE
Fig. 197 shows a portable prony brake consisting of a
belt about 4 ft. long and 2 in. wide. To one end is attached a
spring scale C, having a capacity of 100 Ib. The scale D, with
a capacity of 25 Ib., is fastened to the other end. Both scales
FIG. 197 PORTABLE PRONY BRAKE
are joined to a common handle E. The belt B must be very flex-
ible and must be lined with hard-maple blocks where it comes in
contact with the pulley. The blocks may be Vz x 1 x 2 in. and
should be attached with rivets having the heads countersunk in
the wood.
In use, the belt is placed on the pulley A as shown ; the handle
264 AMERICAN MACHINIST SHOP NOTE BOOK
E is pulled until sufficient braking is secured. The scales are
then read, and the reading on the small scale is subtracted from
the reading on the large one. The remainder is multiplied by
the peripheral speed of the pulley per minute, which gives the
foot-pounds.
BUSHING A LOOSE PULLEY
Both the pulley and shaft were badly worn but the size of the
shaft at A y Fig. 198, could not be changed. The illustration
shows how the pulley was bored out and how the shaft was
turned down. The bushing was bored an easy running fit for
Bronze Bushing
FIG. 198 BUSHING FOB LOOSE PULLEY
the shaft and turned the same for the pulley. A hacksaw did
the rest.
While this kind of a job may be subject to criticism, there is
one thing to be said in its favor it worked.
SURFACE-GAGE KINK
A large number of duplicate castings had to be laid out with
two holes out of line with each other, so I used two scriber
points on the same surface gage and marked both lines in one
operation. This reduced the working time on the job consid-
erably without extra effort on my part.
OPERATING VALVE FOR PNEUMATIC CHUCKS
To overcome the objections usually found with three and four
way cocks, the special air valve shown in the diagram is sug-
SHOP TOOLS, APPLIANCES AND EXPEDIENTS 265
gested. This is a plain slide valve which, when the spindle is
at its highest point, is held in the release position against the
FIG. 199 SELF-ACTING AIB VALVE
pressure of the coil spring by the stop A, which is secured to,
and is adjustable upon, the lower part of the spindle quill.
When the spindle is fed downward, either by hand or power
266 AMERICAN MACHINIST SHOP NOTE BOOK
feed, the valve stem and valve are free to move, and are forced
downward by the coil spring, uncovering the port P and ad-
mitting air behind the operating piston of the chuck. The
chuck then closes upon the work and remains so until the
spindle again rises to its highest point, when the valve is re-
turned to its original position and the air exhausted from be-
hind the piston. It will be seen that the valve has a short
travel, and a relatively short movement of the spindle is re-
quired to produce the desired result. This is a very advanta-
geous point.
In Fig. 199 the valve is shown connected to a single-acting
cylinder. If it is desired to use it with a double-acting cylinder,
the plug B is removed and connection made to the other end of
the cylinder, through the port E.
While a valve of this type is particularly adapted to drilling
and tapping machines, it may be applied advantageously to other
machines also.
When used with an automatic drill and with a chuck from
which the finished work falls by gravity, it is only necessary for
the operator to place the work in the chuck, and a marked in-
crease in the production results.
HANDY TOTE BOX
.These boxes, used in conjunction with an elevating truck, have
proved very satisfactory, as they can be stacked three or four
high. They take but little floor space as compared with stack-
ing rough or semi-finished parts on the floor.
DRILLING THIN STOCK
Those who have occasion to drill thin stock will find in the
following paragraphs a suggestion that will certainly overcome
chattering of the drill after it begins to break through the
stock; moreover, a round hole is obtained. Nor is it necessary
to make an expensive drill plate for drilling thin sheets.
Referring to Fig. 201, it will be seen that the drills are
ground in such a manner that the outer edge A comes in contact
with the stock. The center B, which is slightly in advance of
the cutting edge of the drill, acts as a pilot to locate the drill in
'T*
BLACK SHT IRON
(Bend on dotted lines to
form box)
c
E
FIG. 200 HANDY TOTE Box
FIG. 201 DBILL POINT FOB THIN STOCK
267
268 AMERICAN MACHINIST SHOP NOTE BOOK
the center punch hole and also tends to keep the drill steady
while it is cutting through the stock.
Those who have had much experience in drilling thin stock
with an ordinary twist drill have doubtless seen it go spinning
round like a pinwheel, at the same time severely cutting their
hand. They will be surprised to know that there is absolutely
no need of holding the stock while it is being drilled. Again,
contrary to the usual practice, it is not necessary to drill into a
block or some other material in order to support the stock. It
is really essential, to get the best results, to have no support
whatever under the drill itself, only some means of supporting
the stock; for instance, a V-block or a flat vise may be used.
One of the good features of this drill is that very thin stock
and even paper can be cut with equally satisfactory results and
safety.
TEMPLET FOR MARKING OFF FLANGES
On the flanges of valves and fittings it often occurs that there
is the same number of bolt or stud holes, but the pitch circle
and outside diameter of the flanges vary Tables I and II give
FIG. 202 TEMPLET FOB MARKING OFF FLANGES
the details of standard flanges with eight bolt and stud holes, as
the case may be. The first table is for American standard low-
pressure flanged valves and fittings, and the second table is for
SHOP TOOLS, APPLIANCES AND EXPEDIENTS 269
American standard extra-heavy flanged valves and fittings. A
templet for marking off these flanges is shown in Fig. 202,
for eight equally pitched slots. One side of the templet, shown
to the left, is for marking off the low-pressure flanges, and the
opposite side, shown to the right, is for marking off the extra-
heavy flanges. The figures on the templet carrying two parallel
lines represent the outside diameters of the flanges, and the other
figures the pitch-circle diameters. Suppose, for example, a stan-
dard low-pressure flanged valve is to be marked off with a 9^-in.
pitch-circle diameter; the outside diameter of the flange in this
TABLE I. AMERICAN STANDARD LOW-PRESSURE FITTINGS
Diameter of Diameter of Number of Size of
Flange, In. Bolt Circle, In. Bolts Bolts, In.
9 7i/ 2 8 %
9% 7% 8 %
10 8y 2 8 %
11 9V 2 8 %
10% 8 %
11% 8 %
TABLE II. AMERICAN STANDARD EXTRA-HEAVY FITTINGS
Diameter of Diameter of Number of Size of
Flange, In. Bolt Circle, In. Bolts Bolts, In.
8% 6% 8 %
9 714 8 %
10 7% 8 %
101/2 sy 2 8 %
11 9% 8 %
FIG. 203 DETAILS OF PIPE FLANGES
case is 11 in. First, set the lines with 11 in. marked opposite
until they correspond with the outside diameter of the flange at
all four points. For marking off the holes, the small hardened
piece A, shown in the center of Fig. 202, is used. This is checked
down, as shown, to fit the slots in the templet and to be a nice
sliding fit in it. With the sliding piece in place, the mark A,
is brought opposite the required pitch-circle diameter, in this
case 9^ in. The hole is then marked off either with a scriber
or a ring punch. A handy tool for transferring holes is made of
a piece of round cold rolled steel fitting the hole in A and with a
short spur of hardened tool steel set eccentrically in the end.
270 AMERICAN MACHINIST SHOP NOTE BOOK
IMPROVED HERMAPHRODITE CALIPER
Fig. 204 shows an improved hermaphrodite the design
of which is somewhat out of the ordinary. The tool itself is
made from a common pair of dividers, one leg of which is flat-
FIG. 204 IMPBOVED HERMAPHRODITE CALIPER
tened and fashioned after the shape shown, so that it can be used
for locating from inside or outside edges.
WHITE SURFACE FOR LAYOUT
For general layout work on both rough and finished surfaces,
difficulty is usually experienced in getting a surface that will
show a line plainly and not rub off too easily.
I have hit on a plan of mixing a little shellac with wood
alcohol to make the chalk stick. Keep the alcohol in a can or
bottle tightly corked, as it absorbs moisture from the atmos-
phere, and when so diluted will not dry so quickly. Put a hand-
ful of dry shellac in a gallon of wood alcohol. Take a small
quantity of powdered chalk or whitening and mix as needed to
the desired consistency, with the thin shellac solution. The re-
sult is a surface as easy to work on as drawing paper.
IMPROVED GEAR PULLER
Recently I was watching a machinist while he was engaged in
removing a gear from the end of a shaft. I noticed that he was
being put to considerable trouble and annoyance. In the first
place, the gear was on the shaft quite some distance from the
end, and was very tight. In order to start the gear, it was nec-
essary to remove the long screw from the gear puller, owing to
SHOP TOOLS, APPLIANCES AND EXPEDIENTS 271
the tendency of the screw to twist off when it was forced against
the end of the shaft. After putting a short screw in the gear
puller, and starting the gear, the man was obliged to put the
long screw back in the gear puller. The machinist also had the
annoying job of holding the gear puller straight and central
with the shaft while turning up the screw against the end of
the shaft, a job that makes a man wish he had three hands. To
overcome this trouble a gear puller was built as illustrated in
the sketch. To use this puller the large screw B is turned so
that the end projects through C a short distance. The screw A
FIG. 205 IMPROVED GEAR PULLEB
in turn projects somewhat through B. The gear puller is hooked
to the gear to be removed, and the large screw B is turned to
loosen and start the gear. When started, the long screw A is
utilized to remove the gear the rest of the distance.
Some question might come up as to why a large screw, long
enough to remove the gear and heavy enough to start the gear
without distorting the screw, could not be used. In answer to
this I would say that my main reason is that it was desired to
make the gear puller as light as possible. As is generally known,
the greatest difficulty in removing a gear or anything else of
that nature is to get it started. Once started, it is a simple
272 AMERICAN MACHINIST SHOP NOTE BOOK
matter to remove it the rest of the way. It is extremely annoy-
ing when the piece is almost off to find that the screw is in as far
as it can go. This means the doubtful pleasure of backing the
screw out and setting up all over again. With this gear puller
the smaller screw can be made a good length, and the piece re-
moved the first time.
BOLTS STUCK IN SOCKET WRENCH IN
BOLT-CUTTER
While threading short bolts, holding them with a socket
wrench clamped in the cutter jaws, I found that the bolt heads
jammed in the socket after the thread was cut. This I over-
came by drilling a hole entirely through the socket wrench and
using a rod to drive the bolt out when it stuck in the socket.
DEMAGNETIZING HIGH-SPEED STEEL
A common method is to shift the piece back and forth across
the poles. This will usually free the piece from magnetism, but
I have known this to fail also.
Another method is to take a piece of tissue paper and place it
between the piece and the poles of the demagnetizer. Shift the
piece back and forth across the poles and thus draw the mag-
netism through the paper. This will take every trace of mag-
netism from the piece. I am speaking of high-speed steel and
hope that this will be of benefit to some reader.
RAISING THE " VISIBILITY" OF THE OIL HOLES
IN SHADOWED POSITIONS
In overhauling the machines and shafting in our shop we dis-
covered that some oil holes were in shadowed positions some-
what difficult to see and were consequently liable to be over-
looked. We painted a white ring around every oil hole on every
bearing in the shop and believe the time taken in so marking
these spots to have been well spent.
Oil holes that were formerly rather difficult to locate now
show up plainly, a feature that makes them more apt to receive
the proper attention.
SHOP TOOLS, APPLIANCES AND EXPEDIENTS 273
A BRAKE FOR HIGH-SPEED MACHINES
We will assume that the machine is provided with the usual
type of reversing countershaft having clutch pulleys for open
and crossed belts, and that only one of these is required on the
work the machine is doing. Place a piece of belt around the
idle pulley, carry the ends up to the ceiling, and after stretch-
ing it tight fasten it by passing it under a piece of board, which
is then screwed to the ceiling. This answers the purpose of a
brake band, and the action is as follows: When the operator
wishes to stop his machine he throws over the clutch lever, re-
leasing the clutch in the driving pulley and engaging it in the
pulley around which the band has been placed. The machine is
brought to an immediate stop without undue jar, as of course
there is a certain amount of slippage both of the brake band
and the machine-driving belt. This is an ideal arrangement as
has been proved by thorough trial on a number of current lathes
used on time-fuse work where it has given entire satisfaction.
LENGTH OF BELTING IN COILS
To find the approximate length of a belt in a roll when closely
coiled : Add together the diameter of the roll and the diameter
of the center hole, both in inches. Divide by 2 to get the mean
diameter. Multiply by the number of coils in the roll and by
3.1416, which will give the result in inches. Or divide by 12,
and the result will be in feet.
Example How many feet of belting in a roll 48 in. in diam-
eter with a 6-in. center hole and 60 coils ?
48 + 6 = 54; 54-^2 = 27
27 X 60 X 3.1416 = 5089% in., or about 424 ft.
An abbreviation of the above method is as follows: Add to-
gether the diameter of the roll and the diameter of the center
hole, both in inches ; multiply by the number of coils in the roll
and by 0.131: The result will be the approximate length in
feet, regardless of the belt thickness. The 0.131 is obtained by
dividing 3.1416 by the 2 and the 12 first mentioned. This
method of checking our supply of belting has been in use by us
for some time with perfect satisfaction.
274 AMERICAN MACHINIST SHOP NOTE BOOK
EXPANDING AIR CHUCK
The chuck shown in Fig. 206 was designed to hold brass
nuts during forming, but it will hold any similar work inter-
nally. It is operated by compressed air, the cylinder being at
the other end of the spindle.
This chuck consists of a sleeve threaded on one end to fit the
spindle and bored any convenient size, in this case 2 in., with a
wall between having a ^-in. hole to guide the bolt that opens the
jaws. The bolt is % in., with a %-in. head, and it has a 60-deg.
FIG. 206 EXPANDING AIE CHUCK
taper on the under side to fit the taper in the jaws. A 60-deg.
taper is about right for a 6-in. air cylinder and 75 Ib. air
pressure.
Four holes in the sleeve are tapped for headless screws that
extend through and fit loosely in the holes in the jaws, to keep
them from coming out or turning. The jaws carry springs to
make them close when released by the bolt. They are easy to
make.
For work smaller than the hole in the sleeve, a piece of shaft-
ing the size of the hole can be cut off, faced on one end, then
inserted in the sleeve, and the sleeve used as a jig to drill the
holes in the jaws. One or two screws are put in to hold the jaw
blank, and the whole fixture is screwed on the lathe spindle.
SHOP TOOLS, APPLIANCES AND EXPEDIENTS 275
The projecting end is turned or threaded the required size,
and the hole for the bolt is bored enough larger than the bolt to
allow the jaws to close. The jaws are then numbered, taken out
and sawed apart. Holes are drilled for springs, which are
inserted.
When locked, the chuck is like a solid mandrel, and the nut or
other work can be screwed on easily. When the operation is
completed, the air is turned off, the jaws collapse, and the work
comes off without stopping the machine.
FIG. 207 TUBE BENDING DEVICE
276 AMERICAN MACHINIST SHOP NOTE BOOK
TUBE-BENDING DEVICE
At A, Fig. 207, is a cast-iron base ; J5, the forming block,
pivoted on the stud C, has a groove milled around its three sides,
the radius of the tube to be bent. A clamp block D has a groove
milled to correspond, but M6 in. less in depth to allow for clamp-
ing. A block F holds in position the mandrel E, which is made
of steel, slightly rounded on its front edge and hardened. It is
to be a sliding fit in the tube. The block B is turned by the
handle H. A collar G can be set to adjust the length of the
bend.
In operating this device, open the clamp block D, slide the
tubing into the opening between B and D, on the mandrel E,
against the set collar G, and tighten the clamp block D. In
grasping the handle H, bringing the forming block B around a
half turn, it will be plainly seen that the tube is pulled off the
mandrel without kinking or injuring the tubing in the least.
The writer has tried this device on various diameters of brass
tubing, and it works out perfectly.
CONCEALED SPRING FOR USE ON A RATCHET
PAWL
In Fig. 208 .to the left is shown a spring pawl with the spring
concealed. One end of the spring is bent at right angles and
enters a hole in the washer. The other end, also bent in the
same manner, enters a hole in the pawl. This would provide a
FIG. 208 PAWLS WITH CONCEALED AND EXPOSED SPRINGS
means of adjusting the washer, which in this case is knurled.
In placing the washer against the stud shoulder and tightening
the nut, the washer will be held in place and may be adjusted
to give the desired tension.
SHOP TOOLS, APPLIANCES AND EXPEDIENTS 277
The one to the right is on the same principle as the first,
only the spring is not concealed. The collar is turned a loose
fit for the spring.
AN EMERGENCY REPAIR JOB
Fig. 209 shows a device by which a difficult operation was
done simply and rapidly and with such means as are at hand
in any machine shop.
FIG. 209 TRUING A COUNTERBORED HOLE
In a large shell-forging plant, it became necessary to true up
the counterbored holes used for centering the die holders on
the bases of the 700-ton hydraulic presses. These bases were
not only heavy and imbedded in concrete, but were more or less
inaccessible due to the upper structure, the cylinder being sup-
ported at a height of several feet on four columns placed 4 ft.
apart. The heavy work done on the presses having battered the
counterbored holes out of true, it was decided to bore them out
and put in removable bushings.
A 20-in. Superior drilling machine was removed from its
base and clamped to the press base in the manner shown. An
278 AMERICAN MACHINIST SHOP NOTE BOOK
extension arbor was turned up to fit the drill socket. The lower
end of this arbor was guided by a bearing held by a four-arm
spider in the hole below the depth of the proposed machining.
Keyed and set?screwed to the arbor was a special tool-carrying
Br-
on which was mounted a cross-slide and toolpost re-
moved from the compound rest of a lathe. Some nice laying
out was necessary to make the comparatively bulky tool-carrier
swing inside the hole to be bored which was 15% in. diameter by
SHOP TOOLS, APPLIANCES AND EXPEDIENTS 279
1% in. deep, but so carefully was the work carried out that the
job was finished to a limit of 0.002 in. in an average time of
about 23 hours for each press.
OVERCOMING LOOSE-PULLEY TROUBLE ON A
SPECIAL DRIVE
In Fig. 210 is shown the general arrangement of the driving
pulleys on the shaft of an extractor (textile machine). A dif-
ferent size of pulley is mounted at each end of the shaft. When
the machine is not in use the belt at each end is running idle
on the loose pulley.
When winding goods on the drum, which is secured to the
shaft, the belt is shifted to the large tight pulley, and the drum
will then run at 27 r.p m., while the small loose pulley runs at
an approximate speed of 410 r.p.m.
The goods being all wound on the drum the belt is shifted
back on the large loose pulley and the belt at the other end
Thread or? Stvd to be
opposite tfand of
fotafion of Pulley so
Mat Pulley would
fend to tighten Collar
necessary to
these. Bearings
adjustable because
the Height of the
FIG. 211 IMPROVED METHOD OF MOUNTING PULLEY
moved to the small tight pulley, thus making the drum run
about 410 r.p.m. The outcome is that the shaft revolving inside
of the large loose pulley at this high speed acts as a lap; the
result being the rapid wearing of the bushing in the pulley.
All kinds of bronze and wood bushings were tried, but none
of these stood up very long, and the repair of the machines
became quite an expense.
280 AMERICAN MACHINIST SHOP NOTE BOOK
Finally the writer worked out the following plan, which has
now been tried on two machines for about a year, and has been
found to be successful as no bushings have had to be replaced
on these machines during that time. Improvement, as applied
to two machines, is shown in Fig. 211, and consists of a separate
cast-iron stand C. This stand is secured to the side frame D
of the machine. At the top of the stand C is fastened a cast-iron
bearing bracket E, which serves to hold a stationary stud F.
This stud which has a head G at one end large enough to be a
running fit in the pulley hub H, is held in the bracket E by
means of two setscrews /. The pulley is provided with a bronze
bushing /i, and an oiler L of the talcum-candle type. From the
illustration it will be seen that the loose pulley is absolutely in-
dependent of the shaft. Consequently, no matter how fast the
shaft may be running the loose pulley is not affected and the
bushing does not wear out. I will say, however, that this plan
was used only for holding the large, and slow-running pulley,
because this one caused most of the trouble, and not much would
be gained by mounting the small loose pulley in the same man-
ner. While this improvement is used on textile machinery
there is no reason why it could not be applied to all kinds of
machinery where a somewhat similar set of operating condi-
tions have to be contended with.
COOLING A SMALL AIR COMPRESSOR
Considerable difficulty was encountered in maintaining a suf-
ficient supply of air because the compressor persisted in heating
up. We had decided that the compressor was too small, and
were about to order a larger unit when the writer decided to
make a more complete investigation. While going over the
water-cooling connections an air-compressor erector stopped in,
and after a brief inspection explained the cause of our trouble.
The original water connection was made as to the left in Fig.
212. With this system of piping, a body of cooling water could
not be maintained around the cylinder, but instead merely ran
over the cylinder in a thin film, and out to waste. The com-
pressor erector advised revising the water-cooling connection as
per sketch B, from which it will be observed that the water
jacket would be completely filled with water at all times. These
SHOP TOOLS, APPLIANCES AND EXPEDIENTS 281
simple piping changes were made, and as a result we had an
abundance of air.
FIG. 212 ORIGINAL AND REARRANGED PIPING
SMALL STUD GEAR FOR ENGINE LATHE
On many screw-cutting' lathes compounding becomes necessary
earlier than otherwise, for the reason that the stud gear is al-
ready so small that to reduce its size further would mean to cut
it open through the keyway.
FIG. 213 REINFORCED PINION
To make it possible to use a stud gear with a minimum of
diameter and of maximum strength the writer designed the
282 AMERICAN MACHINIST SHOP NOTE BOOK
pinion shown in Fig. 213. As will be seen, the diameter of the
gear could not well be decreased without cutting into the key-
way, but the ring of metal which comes beyond the shoulder of
the stud furnishes sufficient strength to make it serviceable.
With a pinion of 18 teeth, which can be used on a lathe whose
smallest stud gear is usually of 36 teeth, the finest thread is im-
mediately multiplied by two and thus compounding is avoided.
OPERATING SIGNAL BELLS FROM A GENERATOR
Thinking it might be of advantage to other shops, we wish to
report a little arrangement that we rigged up the other day in
our shop, which has given very satisfactory results.
We all know what trouble signal bells give on a battery cir-
cuit due to the battery getting weak and becoming a constant
source of trouble. We have a six-pole direct current generator
TOBELLS
CIRCUIT
'/8K
FIG. 214 BELL CONNECTION FROM DYNAMO
from which we take power from our shop. On each side of one
of the field poles we connected a wire, which in turn is con-
nected through a double pole switch to our signal-bell circuit, as
shown in Fig. 214. This arrangement does not reduce the
SHOP TOOLS, APPLIANCES AND EXPEDIENTS 283
efficiency of the generator to any appreciable extent, and it will
ring as many bells as it is desired to put on. It has also elim-
inated all the battery trouble which we have had in the past.
SPEED-REDUCTION DEVICE WITH NOVEL AND
VALUABLE FEATURES
The device here described and illustrated allows a variation
in ratio by the simple expedient of changing a couple of gears
not unlike the change gears of a lathe.
FIG. 215 SPEED REDUCTION DEVICE
Referring to Fig. 215, A is the shaft upon which is keyed
the tight pulley B and the spider C which carries the re-
ducing gears. D is a loose pulley upon the hub of which is the
worm E meshing with wormwheel F keyed to a short shaft car-
ried by the spider C. Upon the shaft with wormwheel F, and
also keyed to it, is a gear G meshing with gear H upon a similar
shaft which carries the worm 7. This worm meshes with worm-
wheel J which is made integral with the ratchet K.
When the belt is on tight pulley B the whole mechanism re-
volves as a unit, but when the belt is shifted to loose pulley D
the movement is as follows: The top of the pulley moving
away from the observer moves the small wormwheel in a contra-
clockwise direction. This worm, through the medium of gears G
and H, drives worm I in the opposite direction, which would
tend to drive the wormwheel J and ratchet K in a direction
opposite to that of the driving pulley.
284 AMERICAN MACHINIST SHOP NOTE BOOK
As movement in this direction is opposed by the pawl L it fol-
lows that the spider C, which it will be remembered is keyed to
the shaft, will be forced to revolve in the same direction as the
driving pulley and at a speed determined by the ratio of reduc-
tion in the gearing.
Let us suppose worm E to be single thread and wormwheel F
to have 10 teeth, the same data to apply to worm and wormwheel
/ and J respectively. With gears of equal diameters at G and
H the speed ratio would be as 1 to 100. This can be modified
by using any desired ratio at G and H, it being necessary only to
provide gears whose combined pitch radii equals the center dis-
tance of the two shafts.
AN ADJUSTABLE GEAR FOR ELIMINATING
BACKLASH
A gear made in two parts, with one part adjustable in relation
to the other, is shown in Fig. 216. The writer was hav-
ing trouble with a train of gears on a grinding machine, the gear
teeth wearing down quickly, owing to the presence of loose
FIG. 216 ADJUSTABLE GEAB
SHOP TOOLS, APPLIANCES AND EXPEDIENTS 285
emery, and becoming very noisy. As a means of overcoming
this difficulty, this gear was devised.
Part A is made one-half the thickness of the required gear
with hub B, the length of which is equal to the full thickness.
This hub is threaded on its outer diameter and part C, also one-
half the gear thickness, nicely fitted to it. Two conical seats D
are machined in part A and two corresponding conical-pointed
setscrews E tapped into part C. The center distance of the seats
D is, however, greater than the corresponding distance E by an
amount" equal to nearly one-half the diameter of one setscrew.
The parts are screwed tightly together, in which position one of
the screws should come into alignment with its seat, and this
screw r is tightened. The other screw is now set down as far as
it will go, but it will of course bear upon one side of its seat.
With the parts in this relation the teeth are cut on the gear.
Now by loosening the first screw a trifle and tightening the
the other the parts of the gear are turned slightly in relation
to each other, as shown at F in the assembled drawing, adjust-
ing the gear so that one-half drives in one direction and the
other half drives in the reverse direction, thereby eliminating
the backlash.
ELIMINATING BREAKAGE OF BOLTS ON HIGH-
SPEED MACHINERY
After experiencing a great deal of trouble with the breakage
of wedge bolts on the crankshaft and cross-head bearings of a
high-speed air compressor, I eliminated it by the use of a copper
washer about 0.012 in. thick under the head of the bolt. I be-
lieve this simple device will be equally effective on engine work
or any other place where bolts are subjected to jar and vibra-
tion.
Where a nut is used there should be a copper washer under
the nut as well as under the head of the bolt.
A PNEUMATIC RAM
Fig. 217 shows a pneumatic ram, or "gun," which is used
around the shops for knocking bolts out of a locomotive frame or
similar work, which is usually done with a sledge and which
necessitates taking up an awkward position under the machine.
286 AMERICAN MACHINIST SHOP NOTE BOOK
It will strike three or four times as fast as a man can with a
sledge, and as it delivers a full blow every time it is much more
efficient. The base is a casting, the under side of which is check-
ered so that it will not "walk around" when in use. The cham-
ber of this base is threaded to take a piece of 3-in. extra-heavy
pipe bored out smooth to form the cylinder. The ram should be
FIG. 217 PNEUMATIC RAM
a fairly close fit and its upper end reduced in diameter for about
six inches of its length, so that it will not upset and stick in the
cylinder. An ordinary plug cock forms the operating valve,
the exhaust being through the waste orifice. To facilitate han-
dling the tool and to hold it in position a pair of handles are
provided. This device is not perhaps quite so quick in its action
as the gun powder bolt drivers used in railroad shops for driving
out bolts which have rusted in and stuck in their holes, but it is
very much safer in use.
SHOP TOOLS, APPLIANCES AND EXPEDIENTS 287
CUTTING A KEYWAY ON A LARGE PULLEY
Having occasion to cut a keyway in a pulley that was too large
to be handled by the usual methods where a keyseating machine
is not available I devised the kink shown in Fig. 218.
Take any piece of round iron A to fit the bore of the pulley
FIG. 218 THE WORK AND THE BROACH
and cut a keyway in it to match the one desired in the pulley,
but deep enough to cover the broach B, which should be made a
sliding fit.
By packing under the broach at C with successive pieces of
288 AMERICAN MACHINIST SHOP NOTE BOOK
tin or other sheet metal and keeping the broach well lubricated
a good keyway may be cut in the pulley in a very short time.
In cur case the broach was driven through with a hammer as
the work was too large to get into an arbor press.
AN EMERGENCY REAMER
Our millwright recently had occasion to ream the cast-iron
sleeve of a clutch on our main drive, and as time was an impor-
tant factor the reamer shown in Fig. 219 was improvised.
FIG. 219 IMPROVISED REAMER
The sleeve was 22 in. long and 3 7 /i6 in. bore, from which 0.007
in. of metal was removed in about half an hour of actual ream-
ing.
He first turned a piece of hard wood 30 in. long to fit the hole
to be reamed and inserted a cutter as shown in the illustration.
The necessary curvature of the cutter was secured by forming it
over a piece of pipe of the proper diameter to make it fit the
recess chiseled in the bar. The cut was adjusted for size by
packing tissue paper under the cutter.
CROWNING A LARGE PULLEY
It was in a little country shop, where the largest lathe was
16-in. swing, and the pulleys in question were about 30 in. in
diameter.
I chucked a piece of pipe in the lathe a little longer than the
bed, put the steadyrest as near the tail end of the lathe as pos-
sible, clamped the pulley on the end of the pipe, built a rest out
of 2 x 4 scantling, made a turning tool out of an old file, and I
SHOP TOOLS, APPLIANCES AND EXPEDIENTS 289
was ready for the job, which was done satisfactorily and in good
time. This is probably not a new stunt to most oldtimers.
WHY BELTS JUMP
The real cause of leather belts jumping to the next cone pul-
ley step, and in some cases twisting over is entirely due to the
fact that some section of the belt is stretched more on one side
than on the other. This is due to the fact that the strip of
leather composing the belt has been cut too low down the side of
the hide. The very best belts are always cut out of the center
of the back of the hide as this part usually yields a leather about
WQ in. to y* in. thick, and the further you get from the center of
the back, the thinner the leather obtained; hence, inferior qual-
ity and strength ; the thinnest side stretching most. I have had
to adopt balata belts in preference to leather, although I much
prefer the leather for several reasons.
FASTENING LOCKNUTS
On some types of machines subjected to a large amount of
vibration it is hard to prevent locknuts from working loose. If
spring lock washers cannot be used, a thin copper washer cov-
ered with a dilute copper sulphate solution will take care of any
tendency of the nuts to work loose. The copper washer, being
soft, acts like a spring washer, and the solution tends to freeze
the nuts and washer together.
KEEPING BELT GLUE IN BOTTLE
We used to keep our belt glue in an iron pot. After the first
time it was used it was not much good, as it would often be
months before it was needed again. It would then be pretty
well dried out, requiring long heating before it was ready for
use.
We now keep our belt glue in a bottle, heating it up in a pot
of water. In this way it does not get hard, as it is not exposed
to the air, and only a few minutes' heating makes it ready for
use.
It is just as well to remember to put the bottle in cold water
and heat gradually; do not immerse in boiling water.
290 AMERICAN MACHINIST SHOP NOTE BOOK
PREVENTING GREASE-CUP TROUBLE
Much trouble has been experienced by green help screwing
grease-cup plungers down and against the bottom of the cup. \
have done away with this trouble by putting a sleeve between
the handwheel and the cover. I make the sleeve exactly long
enough so that the handle takes up against the sleeve just be-
fore the plunger reaches the bottom of the grease cup.
A MOLD FOR BABBITT HAMMERS
Manufacturers and machine builders who use a large number
of babbitt hammer, or mauls, in their shops often find the ordi-
nary hand mold a rather slow proposition and should be inter-
ested in the air-operated mold shown in Fig. 220. In a
shop where a large number of babbitt hammers are used, often
several hundred being made at one time, old methods proved
too slow and the air-operated mold shown in the illustration was
FIG. 220 MOLD FOB BABBITT HAMMEBS
devised. It is of simple construction and can be easily made by
any one familiar with machine work.
A cast-iron base has bolted to it the cylinder A, which carries
a piston and piston rod on one end of which is fastened one-
half of the mold B. On the upper part of the cylinder is a two-
way valve C operated by the handle D. The inlet pipe E comes
in from the back of the valve and the exhaust pipe F leads from
the front. On the opposite end of the base and in alignment
SHOP TOOLS, APPLIANCES AND EXPEDIENTS 291
with the cylinder is bolted a support G for the other half of the
mold, the two halves being held in alignment when closed by
the two wedge-shaped lugs H, which enter corresponding open-
ings in the other half of the mold. The two straps / are slotted
to receive bolts which hold them firmly to the outer half of the
mold and prevent the half which is attached to the piston from
turning. The pouring gate is above and a little back of the
center so that any overflow of metal falls into a pan at the back
of the mold and does not spatter on the workman.
The mold shown in the illustration is for a small hand ham-
mer, but larger ones can readily be put on for mauls or for ham-
mers with gas-pipe handles. The molds for the latter have an
opening to receive the handle so that the metal can be poured
around it.
In operation a movement of the handle D in one direction
closes the molds, and throwing it in the opposite direction opens
them for removal of the finished hammer.
FIBER HAMMER
The ordinary fiber hammer usually has some projection of a
larger diameter than the fiber heads, so that if a workman misses
hitting his work with the fiber face, he is pretty sure to strike
FIG. 221 FIBER HAMMER
it with the projection. Usually this projection is in the form
of a threaded ring that retains the fiber head in the body of the
292 AMERICAN MACHINIST SHOP NOTE BOOK
hammer. I made the hammer shown to overcome any such
objection to its use.
It consists of a brass body A, bored at each end to receive the
two fiber plugs B, which are held in by taper pins. When the
fiber becomes worn, it is an easy matter to knock the taper pins
out and put in new fiber. These pieces are drilled and taper-
reamed in place and then pinned. There are no projections, as
the fiber plugs are of the same diameter as the brass body of the
hammer. A hammer made to the dimensions shown will be
found far superior to small lead or babbitt hammers and will
last almost indefinitely.
COMBINED HARD AND SOFT HAMMER
Fig. 222 shows a handy hammer to have around the shop, as
it combines in one tool a hard and a soft hammer of suitable
FIG. 222 COMBINED HARD AND SOFT HAMMER
weight for driving keys or assembling or disassembling other
machine parts that are machined to a drive fit.
The hammer head is a steel casting with one end cored out to
receive the copper plug which is forced in and further secured
by the rivet passing through it and the casting.
The hammer weighs about five pounds.
SHOP TOOLS, APPLIANCES AND EXPEDIENTS 293
HOW TO KEEP A HAMMER ON THE HANDLE
My hammer kept coming off the handle, so my shop partner
put me next to this kink : I removed the iron wedge that was in
FIG. 223 TUBULAR WEDGE FOR A HAMMER
my hammer and drove in a hardwood one, then one like the one
shown in Fig. 223 on top of the wood. It is made of ^-in. pipe
ground to a taper and cut off about l /2 in. long.
INDEX
Accuracy of doubtful quality, 4
Accuracy, theoretical vs. practical,
3
Air chuck, expanding, 274
Air hoist, piston packing for, 257
Angle iron, adjustable, 74
Angle plate, tool makers' with V-
slot, 168
Annealing hard spots in oxyacety-
lene repairs, 68
Annealing high speed steel, 45
Arc shaping attachment for lathe
or shaper, 111
Arc welding high speed steel, 43
B
Babbitt hammers* a mold for, 290
Ball center, use of, 93
Ball joint piston rod, 58
Bearing caps, pattern for, 31
Bells, operating signal, 282
Belting, centrifugal force decreases
pulling power of, 19
Belting glue, keeping, 289
Belting in coils, length of, 273
Belting shifter repair, 257
Belting, why belts jump, 289
Bending fixture for tubes, 276
Bending heavy pipe, 63
Bending short rods, 65
Bending wire, 177
Bevel pinions, machining on drill
press, 93
Bleaching blueprints, 23
Blue prints from pencil tracings, 20
Blue prints local bleaching, 23
Blue prints machine, increasing
speed of, 21
Bolt cutter, improved socket wrench
for, 272
Bolts, eliminating breakage of, 285
Boring bar for chambering, 224
Boring bar for 8-in. shells. 10, 11
Boring bar for maximum stiffness,
10, 11
Boring bar for radii, 82
Boring bar for torpedo tubes, 225
Boring chuck for a boring mill, 229
Boring, driving box chuck, 229
Boring engine guides, 85
Boring head for the milling ma-
chine, 137
Boring large holes on boring mill,
226
Boring machine, portable cylinder,
221
Boring mill centering work with
wedges, 233
Boring taper holes, 225
Bosses, turning small, for patterns,
32
Brad driver, 28
Brake for high speed machines, 273
Brake, portable prony, 263
Brazing, preventing spread of heat
while, 70
Brazing stellite, 46
Breakage of roughing tools, 97
Breaking up car wheels, 27
Broaching on the lathe, 113
Bulging die for tubing, 180
Bushing a loose pulley, 2G4
Bushing case hardened jig, 158
Bushing plate in tool work, 151
Butt welding high speed steel, 44
Buttons for angular work, 155
Buttons, special, for close centers,
160
Caliper, hermaphrodite, 270
Cams, dimensions of, 14
295
296
INDEX
Cams for small machinery, 13
Cartridge punches, templet for, 155
Center holes, correcting untrue, 119
Chuck, expanding air, 274
Chuck for nipples and studs, 119
Chuck wrench repairs, 99
Circles, dividing, 9
Cloth, die for, 183
Compressor, cooling a small air, 280
Conservation vs. efficiency, 253
Cooling water for air compressor,
280
Core box dowel pins. 30
Cored holes, clearance for, 7
Cores, horizontal, 9
Cores, vertical, 8
Cores, setting, correctly, 8
Counterbore, an economical, 154
Counterbore, double ended, 81
Counterbore, high speed steel, 81
Countersinking tool, special, 88
Countersunk head bolts, holder for,
261
Cracks in hardening, prevention of,
68
Crane hooks, securing, 258
Cranes in shops, 255
Crank shaft repair, 52
Cross holes in round stock, drilling,
90
Cutters in multiple, hardening, 52
Cutting odd pitch screws, 97
Decimal equivalents of vulgar frac-
tions, 236
Design for new machines, prelimi-
nary, 5
Diamond dresser, 220
Die holder, 246
Dies, transfer gage for piercing, J68
Die work, bending dies for tubing,
190
Die work, curve of throat of draw-
ing dies, 186
Die work, die for rubber washers,
178
Die work, direction of grain of met-
al, 171
Die work, double punch for increas-
ing stroke, 190
Die work, freak shell cause and
cure, 189
Die work, guide for blanks, 185
Die work, ironing surface of draw-
ing dies, 185
Die work, large combination die, 176
Die work, locating small holes ac-
curately, 173
Die work, making piercing punches,
181
Die work, piercing opposite sides of
thin shells, 182
Die work, piercing oblique holes. 188
Die work, preventing breakage of
punch pilots, 191
Die work, producing a bulge in tub-
ing, 180
Die work, rounding vs. short bends,
171
Die work, spring forming die, 184
Die work, spring punch pilots, 191
Die work, standards in dies,
punches and holders, 187
Die work, press work as a substi-
tute for forgings. 171
Die work, use of drill plate in, 175
Die work, vented punches in draw-
ing, 186
Die work, wire bending die, 177
Dog, safety lathe, 99
Dowel pins, 30
Drafting supplies, checking issue of,
2
Drafting table cover, 7
Drafting, drawings for pattern mak-
ers and machinists, 5
Drafting, shellacked drawings for
the shop, 6
Drafting table extension for large
radii, 24
Drafting table, guard for, 23
Drill jig for cross holes, 90
Drill jig for steel discs, 79
Drill jig for yokes, 94
Drill jig for Y-connections. 85
Drill jig positively located, 73
Drilling, adjustable jig for round
work, 76
Drilling cross holes in round stock,
90
Drilling glass, 77
Drilling machine fixture for small
holes, 83
INDEX
297
Drilling machine for tapping, 80
Drilling machine, making angle
faced washers on a, 75
Drilling machine, reduction head
for, 86
Drilling machine used as a press,
87
Drilling steel discs, 79
Drilling thin stock, 266
Drip can for hangers, 254
Dynamometer, portable, 263
Electric welding high speed steel, 43
Ellipsograph, 25
Engine guides, boring, 85
Export, packing machinery for, 17
Fiber hammer, 291
Fixture for thread grinding, 161
Flanges, American standard, 269
Flanges, templet for marking, 268
Follow rest, emergency, 100
Forming die for springs, 184
Forming tool, making a circular,
156
Furnace for oil tempering bath, 61
Furnace for springs, 59
Fusible metal, 26
G
Gage work, adjustable female thread
gage, 197
Gage work, amplifying gage, 201
Gage work, built up snap gage, 200
Gage work, checking up angles on,
196
Gage work, depth gage for recesses,
198
Gage work, errors due to thread mea-
suring wires, 203
Gage work, feeler gage, 196
Gage work, feeler gage for -recesses,
198
Gage work, gage grinding machine,
192
Gage work, grinding snap gages, 205
Gage work, machine for grinding
snap gages, 193
Gage work, grinding interrupted ra-
dii, 198
Gage work, inspection gage, 202
Gage work, measuring device for
threads, 194
Gage work, measuring threads with
wires, 203
Gage work, multiplying gage, 201
Gage work, sealing gages with plas-
ter of paris, 205
Gage work, special V-block for grind-
ing gages, 194
Gage work, a tolerance gage, 202
Gear, adjustable for eliminating
backlash, 284
Gearing, cutting angle for helical
gears, 238
Gearing, decimal equivalent table,
235
Gearing, intermittent worm, 237
Gearing, puller for gears, 270
Gearing, reducing gear, 283
Geometrical progression, 18
Glass, drilling holes in, 77, 78
Graphical geometrical progression,
18
Grease cup trouble, preventing, 290
Grinding, accurate setting device for
internal, 166
Grinding correct radius on gage,
198
Grinding countersink in chilled cast-
ings, 218
Grinding, diamond for Norton ma-
chine, 220
Grinding, disc grinding fixture, 219
Grinding edges of circular plates,
211
Grinding, keeping notes on, 207
Grinding, mounting, balancing and
dressing wheels, 210
Grinding, preventing spring in thin
work, 215
Grinding, radius wheel dressing fix-
ture, 217
Grinding, saving time with extra
bushings, 211
Grinding snap gages, 205
Grinding thin pieces, 215
Grinding wheels for tool and cut-
ter grinding, 213
Grinding wheels radius truing fix-
ture, 165
298
INDEX
Hacksaw blades, economy in, 256
Hacksaw blades used as shaper tools,
148
Hammer, mold for babbitt, 290
Hammer, efficient wedge for, 293
Hangers, drip can for, 254
Hard spots, annealing, 68
Hardened work, soft centers for, 48
Hardening cracks, preventing, 68
Hardening high speed steel, 45, 48
Height gage, vernier caliper as a,
153
Helical gears, cutting angle of, 238
High speed steel, annealing, 45
High speed steel, arc welding tool
tips, 43
High speed steel, butt welding tips,
44
High speed steel, coke as a protector,
51
High speed steel cutters, hardening
temperature, 50
High speed steel, demagnetizing, 272
High speed steel drawing tempera-
tures, 49
High speed steel, forging, 61
High speed steel, hardening, 45
High speed steel, mixture to prevent
scaling, 47
High speed steel quenching medium,
49
Hydraulic cylinder, emergency' re-
pair of, 277
Indicator dial for setting taper at-
tachment, 111
Indicator for table traverse of mill-
ing machine, 129
Intermittent worm gear, 237
Jig, adjustable for round work, 76
Jig bushings, case hardened, 158
Jig for drilling steel discs, 79
Jig for drilling yokes, 94
Jig for drilling Y-connections, 85
Jig, positively located drill, 73
Keyway cutting by hand, 287
Lathe, angles for square threading
tools, 101
Lathe, arc forming attachment for,
111
Lathe, calculating cutting time for,
115
Lathe chuck for nipples and studs,
119
Lathe, correcting center holes, 119
Lathe, cutting coarse pitch screws,
107
Lathe, cutting a worm of rapid lead,
108
Lathe, dividing on, 150
Lathe dog, safety, 99
Lathe, emergency follow rest, 100
Lathe, facing the boss on a large
casting, 100
Lathe, finish turning with stellite,
102
Lathe, floating reamer holder for,
115
Lathe, gang turning fixture, 117
Lathe, high speed steel centers, 106
Lathe jig for turning square tools,
116
Lathe, nonslip expanding mandrel,
109
Lathe, peening grooving tools, 120
Lathe, self centering work carrier,
103
Laths, setting a taper attachment,
1L1
Lathe, sizing piston ring grooves, 120
Lathe, small stud gear for, 281
Lathe, spring threading tool, 118
Lathe, stellite centers, 106
Lathe tail spindle repair, 104
Lathe threading dial explained, 96
Lathe, threading small castings, 105
Lathe used as broaching machine,
113
Layout tool for the milling machine,
122
Layout, white surface for, 270
Locating button, adjustable, 130
Lock nuts, fastening, 289
INDEX
299
Loose pulley, bushing a, 264
Loose pulley troubles, overcoming,
279
M
Machinery, layout of, 16
Machinery packing for export, 17
Machining bevel pinions, 93
Mandrel, expanding nonslip, 109
Marking, white for layout, 270
Micrometer anvils, lapping, 158
Milling machine, adjustable boring
tool holder, 137
Milling machine, adjustable locating
button, 130
Milling machine, adjustable side
milling cutter, 133
Milling machine, adjustable spacing
collar, 133
Milling machine, adjustable V-block,
124
Milling machine boring a curved
hole, 131
Milling machine, clamping flat
square work, 135
Milling machine, crowning pulley
faces, 122
Milling machine, cutter setting tool,
138
Milling machine, determining the ap-
proach of cutters, 130
Milling machine fixtures, efficiency
in, 123
Milling machine, fluting taper ream-
ers, 128
Milling machine indicator, 129
Milling machine, large job on a
small, 124
Milling machine, lathe job on a, 134
Milling machine, substitute for in-
ter-locking cutters, 133
Milling machine, tool for laying out
work, 122
Milling machine, two-way clamp
with one screw, 135
Milling machine vise as a special
fixture, 126
Milling machine vise for use between
centers, 137
N
Nipple chuck, 119
Oil holes, marking, 272
Oil tempering bath, 61
Oxyacetylene welding high speed
steel, 41
Packing for export, 17
Parts and stock, commercial sizes
of, 3
Parts lists, changing, 7
Patternmakers' brad driver, 28
Patterns, herring bone grate, 36
Patterns, marking, 35
Patterns, protectors for, 34
Patterns, rapping plates for, 33
Patterns with projecting members,
'27
Pawl, concealed spring, 276
Pawl, exposed spring, 276
Plate patterns, assembling and ma-
chining, 29
Pencil tracings, blueprints from, 20
Pipe, bending heavy, 63
Piston rod, ball joint, 58
Planing machine, extension tool for.
143, 144
Planing machine, internal tool, 143,
144
Planing machine, milling T-slots in,
139
Planing machine, planing ways of,
140
Planing machine, radius tool, 145
Planing machine, repairing old, 139
Planing machine rigged as milling
machine, 139
Planing machine, studs for, 140
Planing machine, turning and bor-
ing attachment for, 149
Pneumatic chuck, expanding, 274
Pneumatic chuck, operating valve
for, 264
Pneumatic piston packing, 257
Polygons, laying out, 9
Precision tool grinding, 159
Press work, blanking cloth, etc., 183
Press work locating small holes ac-
curately, 173
Press work wire bending die, 177
Prints, filing, 2
300
INDEX
Prony brake, portable, 263
Puller, improved gear, 270
Pulley, bushing a loose, 264
Pulleys, crowning on the miller, 122
Pulleys, crowning large, 288
Pulleys, crowns for various diamet-
ers and widths, 12
Pulleys, repairing loose, 279
Punches, heading jig for piercing,
182
Punching on the drilling machine,
87
Punching small holes in the drilling
machine, 87
Quenching medium for high speed
steel, 49
R
Radii, drawing large, 24
Ram, pneumatic, 285
Rapping plates for patterns, 33
Reamer, built up, 45
Reamer, floating holder for, 115
Reamer, fluting taper, 128
Reamer improvised large, 288
Recessing tool, 89
Reclaiming materials, 67
Reduction head for drilling ma-
chine, 86
Repairs, recording, 57
Roller bearings in machine tools, 13
Rolling threads in the screw ma-
chine, 247
Rustproofing, 172
S
Saving drawing paper, 1
Scrap, reclaiming, 67
Screw, angle for square threading
tools, 101
Screw cutting lathe threading dial
explained, 96
Screw, holder for flat head, 261
Screw, cutting coarse pitch, 107
Screw machine, burring tool, 245
Screw machine guard for cutting
compound, 245
Screw machine, hollow set screw as
adapter, 251
Screw machine, machining piston in
Gridley automatic, 239
Screw machine, slotting and shaping
in, 242
Screw machine, tap and die holder
for, 246
Screws, threading small cast brass,
105
Screw machine time study sheet, 240
Screw machine, thread rolling in
the, 247
Shading and cross sectioning, 2
Shaper, arc forming attachment
for the, 111
Shaping in the screw machine, 242
Shaping machine, clamping large
work on, 147
Shaping machine, cutting narrow
slots, 148
Shaping machine, dividing on the,
150
Shaping machine, extension tool for,
143, 144
Shaping machine internal tool, 143,
144
Shaping machine, machining rectan-
gular hole in, 141
Shaping machine radius tool, 145
Shaping machine, repairing ways
of, 141
Shaping machine tool, hacksaw
blade as, 148
Shaping machine vise, squaring
small work in, 149
Sheet metal work, preventing rust
in, 172
Shell reamer, increasing size of, 80
Shrinking allowance, 71
Shrinking on a large sleeve, 71
Slotting in the screw machine, 242
Snap gage, built up limit, 200
Snap gages grinding, 205
Soft centers for hardened work, 48
Soft hammer, a mold for, 290
Soft hammer, combined hard and,
292
Soft hammer fiber, 291
Soldering, fusible metal for, 26
Special machine design, 4
Speed reduction device, 283
Spherical turning attachment, 98
Spotting in, power device for, 259
Springs, furnace for, 59
INDEX
301
Standard sizes for drawings, 1
Steady rest, self centering work car-
rier, 103
Steam hammer, ball joint piston rod
for. 58
Steam hammer piston repairs 55
Steel, mixture for preventing scale
on carbon, 47
Steel, bits of high speed, 41
Steels, standard marking for, 40
Stellite, brazing, 46
Studs, chuck for, 119
Surface gage, two needle, 264
Taper attachment, setting with dial
indicator, 111
Taper holes, boring, 225
Taper reamer, improved half round,
261
Taper reamers setting angle for, 128
Tap holder, 246
Tapping full threads in bronze, 262
Tapping on small drilling machine,
80
Taps, hardening high speed steel, 47
Templets for cartridge punches, 155
Tempering thin snap gages, 69
Thread grinding fixture, 161
Thread rolling in the screw machine,
247
Threading dial, explanation of the,
96
Threading, external and internal
tool for, 118
Threading full threads in bronze, 262
Threading small cast brass rings,
105
Threading tools, angle of square, 101
Time fuses, drilling fixture for, 83
Time study sheet 240
Tool making angle plate, 168
Tool making, auxiliary bushing plate
in, 151
Tool making, buttons for measuring
angular work, 155
Tool making, cartridge punch temp-
let, 155
Tool making, case hardened jig bush-
ings, 158
Tool making, economical counter-
bore, 154
Tool making, grinding precision
tools, 159
Tool making, lapping a micrometer,
158
Tool making, locating close holes, 160
Tool making, making a circular
forming tool, 156
Tool making, radius truing device
for grinding wheels, 165
Tool making, setting for internal
grinding, 166
Tool making, thread grinding fixture,
161
Tool making, transfer gage for pierc-
ing dies, 168
Tool making, vernier caliper as a
height gage. 163
Tools, built up, 44
Tools, cost of welded, 45
Tote box, 266
Tracing cloth, pencil, 6
Tracings, blueprints from, 20
Tubing, a bulging die for, 180
Tube bending fixture 276
Turning arcs, 111
Turning, finishing with stellite, 102
Turning, gang fixture for, 117
Turning on the milling machine, 134
Turning spherical work, 97
U
Undercutting tool, 89
V-block, adjustable, 124
V-block, special, for grinding, 194
Valve, air chuck operating, 264
Vandykes on cloth and paper, 6
Vernier caliper as a height gage 153
W
Washers, progressive die for rubber,
178
Washers, making angle faced, on
drill press, 75
Waste reclaiming, 254
Wedges used for centering, 233
Welding high speed steel. 41
Wheel puller, 270
Wood, use of, in blanking dies, 179
Worm, casting a, 32
Worm, cutting a rapid lead, 108
Worm gear, intermittent, 237
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