the runway past the front of the main frame. Sweeps 14 in. deep can be
cut. Pipe bends are treated similarly. Fig. 87 shows a half-pattern of small
radius carried directly on the table. The fly-cutter has nearly the same
sectional curve as the bend, and operates on both sides in succession. At
the same setting a regular curve can be combined with a straight length.
When core boxes for bends are being cut, the same method is adopted, the
cutter having a semicircular contour, and the half-box being carried round
a radius or along a straight line as required. But boxes for branch pipes
Fig. 87.—Mechanical Wood-worker operating on small Section as Pattern Bend of small Radius
Any section up to twenty-four inches can be operated upon, and any radius. The whole segment of a circle
may be operated, and straight parts to any extent may be left at either or both ends of bend.
and those with recessed portions are cut with the spindle set horizontally
(fig. 88), with cutters of the sectional shapes required.
Miscellaneous Machines.—The circular and band saws, the various
machine cutters, and the bench edge tools have to be sharpened and kept
in good working order. Though often done without mechanical aids, these
become necessary in the large shops. On the regular setting of circular
and band saws their efficiency mainly depends. Circular-saw teeth can be
set in one machine and evenly sharpened in another. Band-saw teeth are
set and sharpened in one machine. The cutters for planing machines and
other kinds are ground while held in a fixture traversed past the face of an
emery wheel of cup shape. For the small machine cutters and for hand-