Skip to main content

Full text of "Musical Instruments"

See other formats

Solar Xylophone 


Make {Projects 

build, hack, tweak, share, discover. 

Solar Xylophone 

Written By: Rory Nugent 


Dremel rotary tool (1) 

Drill press (1) 
or drill and vise 

Hot glue gun (1) 

Needlenose pliers (1) 

Radial saw (1) 

or other type of saw 

Soldering iron (1) 

Table saw (1) 

or router and fence 

Wire stripper (1) 

© Make Projects 


Xylophone (1) 

You can also check Amazon and eBay. 
To make it less expensive, you can use 
smaller models with fewer tubes, even 
just 1 or 2. if you adjust sizes and 
quantities accordingly. 

• Mallets (8) 
Xylophones typically come with a pair, 
so you'll need to obtain 6 more. Buy 
cheap wooden ones, which are easier to 
drill through. I got mine for $4 each from 

• Voltage triggers (8) 
Transistor (8) 
Measuring tape (1) 

• Potentiometer (8) 

• Electrolytic capacitor (8) 
Monolithic capacitors (8) 
Silicon diodes (8) 
Solar cell (8) 
Geared pager motors (8) Page 1 of 13 

Solar Xylophone 

Dual mini pert boards (4) 
There are 2 boards per package 

Paper clip (8) 

Finishing nails (8) 

Wire (about 15') 

Plumbing solder (1) 

Hot glue (1) 

Epoxy will also work nicely, but takes 

more time to mix and apply. 

Wood glue (1) 

Plywood (1) 


You could go less than W thick, but I 

wouldn't suggest anything less than 1 A". 

Wood plank (1) 

You could go less than 1 1 A" thick, but I 

wouldn't suggest anything less than Ph". 

Wood plank (1) 

Female connector headers (16) 
(optional) These will keep your 
components modular and will make 
testing much easier. 

Male wire connection headers (8) 
(optional) These will keep your 
components modular and will make 
testing much easier. 


Wind chimes capture wind energy to move metal tubes that generate sound when they strike 
one another. They're simple, timeless, and beautiful. You can never predict the composition 
the chimes will play after the next gust of wind, which is what makes these inventions so 
compelling. The elegant overlay they add to our experiences brings us closer to nature. 

© Make Projects 

Page 2 of 13 

Solar Xylophone 

I wanted to create a different kind of autonomous musical instrument that would, like wind 
chimes, generate tones from a natural resource. So I made this solar xylophone, which 
gives voice to the silent sun and takes the project (and ourselves) outside, where we belong. 
It uses eight simple, independent systems to strike its eight chimes in parallel. 

Step 1 — Ready the perf board and parts. 

• Split your RadioShack perf board 
into single squares, or if you're 
using your own perf board, cut it 
into 2"x2" pieces. 

• Collect and separate the parts 
needed to make each circuit: 
voltage trigger, transistor, trimpot, 
diode, 4,700|iF capacitor, 1.0|jF 
capacitor, motor, solar cell, a bit of 
wire, 2 female connection headers 
(optional), and a piece of perf 

Step 2 — Solder a circuit together. 

Take one group of parts and solder 
a circuit together, following the 
Solarengine schematic at . 
This can be a bit tricky but it's 
good practice if you want to get 
better at electronics. I put the 
electrolytic capacitor and the 
trimpot at opposite ends, and 
included 2 female headers for 
connecting to the solar cell and 
motor at the edges. 

© Make Projects 

Page 3 of 13 

Solar Xylophone 

Step 3 — Solder the wire leads. 

After you finish one of the circuit 
boards, solder wire leads onto the 
positive and negative terminals on 
the solar cell. If you're using 
headers, solder male headers to 
the motor's delicate leads (we don't 
need these for the solar cell — the 
22-gauge wire is thick enough). 

Step 4 — Test the circuit. 

# Test your first completed circuit 
board by taking it outside or putting 
the cell under a high-wattage 
incandescent bulb. You should see 
the motor move within 10 seconds. 
A compact fluorescent bulb or 
heavy-duty flashlight will probably 
also work but will take longer, and 
you might begin to think something 
is wrong with your circuit. 

© Make Projects 

Page 4 of 13 

Solar Xylophone 

Step 5 — Fixes 

If it doesn't work, adjust the trimpot 
using a screwdriver, by turning it 
all the way in one direction or the 
other. This controls the efficiency 
of the circuit, allowing more 
electricity to reach the capacitor, 
and thus, adjusting the timing of the 
motor. One side of the trimpot 
resists all the electricity while the 
other resists none. 

The circuit works correctly 
if the motor periodically 
turns about 60° and then quickly 
resets itself. If it works, pat 
yourself on the back, call up your 
friends for help, and build 7 more 
just like it (or however many your 
project calls for). Otherwise, check 
your solder connections, review the 
circuit, and use a multimeter on the 
solar cell and 4,700|jF capacitor to 
see if electricity is flowing. Lastly, 
ask a friend to review the circuit. 

© Make Projects 

Page 5 of 13 

Solar Xylophone 

Step 6 — Cut the platform wood. 

Cut 2 pieces of 1/8" plywood to 
5 1 /2"x15 1 /4" each. These pieces will 
make the platforms that the mallet 
and motor mechanisms rest on. 

Step 7 — Cut the platform legs. 

• Cut 4 pieces of the VA" wood to 3 
1/16"x5 1 / 2 " . These will be the legs 
that support the mallet platforms 
above the xylophone. 

© Make Projects 

Page 6 of 13 

Solar Xylophone 

Step 8 — Make wood cuts. 

• Cut 1 piece of 3/4" wood to 16"x25 
3/4". This is the largest piece of 
wood and will support the entire 

# Take the 1"x1 1/2" wood plank and 
cut 2 pieces 15 1/4" long each. 

Step 9 



fl$ .■"■".• : 



% 1 

• This is the tricky part. Now we'll 
need to put a 1/2"-deep cut along 
the entire 1" edge of each 1"x1 1/2" 
piece. A table saw is perfect for 
this. Place each piece on the table 
with the narrow edge down, adjust 
the fence so that the blade is 
centered on the wood, and run it all 
the way through the piece. Repeat 
for the second piece. 

© Make Projects 

Page 7 of 13 

Solar Xylophone 

Step 10 

Move the pieces back to the radial 
saw and cut four 5/16" slits into 
each, 2 1/4" apart, on the same 
side as the long groove. These will 
be the notches that hold the 
mallets. Start at one end of the 
piece and measure 3 3/16" from the 
end. Mark off a section 5/16" wide 
and 7/8" deep. Measure 2 1/4" from 
the marked section and repeat the 
marking 3 more times. Repeat this 
step for the second piece. 

Step 11 

Glue the 2 plywood platforms on 
top of the 4 leg pieces to make 2 
U-shaped raised platforms. Then 
glue the platform tops onto the 
large piece of 3/4" wood, running 
parallel and centered 2 3/8" from 
each end. Let the glue dry if 

Glue the 2 slotted strips on top of 
the platforms, running parallel and 
1 1/4" in from the outside edges. 
You should now have a nice 
wooden structure that will house 
the xylophone inside, below the 
platforms. Each slotted wooden 
strip will act as a balancing point 
for 4 mallets. 

© Make Projects 

Page 8 of 13 

Solar Xylophone 

Step 12 — Install the mallets. 

Use a 1/16" drill bit to drill 2 holes 
into each mallet, one 5 1/8" from 
the rubber ball end, and the other 4 
1/8" from the bare end. Slide a 10- 
penny nail into the hole closest to 
the bare end. 

Step 13 

Cut and bend your paper clips into the zigzag shape shown here using wire cutters and 
needlenose pliers. These wires will run through the holes closest to the mallets' striking 
ends and drive them from the motor. 

© Make Projects 

Page 9 of 13 

Solar Xylophone 

Step 14 — Final Assembly 

• This part is particularly 
tricky. We need to figure out 
where the motors should be placed 
and how much counterweight 
(plumbing solder) to spool around 
the mallets' ends. 

• Slide the xylophone in place under 
the platforms. Use your eyes to 
center it. 

• Place each mallet with its nail into 
its own groove on the balancing 
strips. The mallets should fall and 
rest on or near the center of each 
pipe. If not, adjust the placement of 
the xylophone underneath, or pull 
out and reverse the nail — the 
head can sometimes push a mallet 
off center. If that doesn't work, 
check the alignment of the strips 
and the placement of the platforms. 
Handcrafting an instrument like this 
takes some tinkering. 

© Make Projects 

Page 10 of 13 

Solar Xylophone 

Step 15 

Grab one of the mallets and wrap 
some plumbing solder around the 
wooden end. You want to wrap just 
enough to make the mallet balance 
nicely in the wooden groove and 
fall slowly down toward the 
xylophone, which requires trial and 

Step 16 

• Place a properly counterweighted 
mallet into the groove, and then 
bring the motor from one of your 
circuits close to the mallet head. 
Fit a bent paper clip into position, 
connecting the motor to the mallet, 
with the short end through the 
eyehole of the motor and the long 
end through the unused hole in the 
mallet. Curve the long end of the 
wire up and around the mallet. 

© Make Projects 

Page 11 of 13 

Solar Xylophone 

Step 17 

Hold the motor slightly offset from 
the mallet, and make sure the 
motor is oriented so that it will pull 
down on the mallet. 

Step 18 

• Test the circuit while holding the 
motor in place. This will give you 
an idea if you've found the right 
spot. If so, mark its position on the 
platform with a pencil. Grab your 
Dremel tool, attach a round wooden 
shaving tip, and grind out the line 
you marked so that the plastic tab 
on the bottom of the motor will fit in 
it. The motor will then sit flush with 
the platform. 

© Make Projects 

Page 12 of 13 

Solar Xylophone 

Step 19 


• Repeat the installations and tests 
for all other mallet/motor/circuit 
combinations. After each motor 
placement mark has been ground 
out, do one last quick test and then 
hot-glue or epoxy the motor into 

• Finally, drill a hole in the balancing 
strips next to each motor and 
thread the motor lead wires 
through. Hot-glue or epoxy the 
solar cells so that they rest at a 
45° angle with the top touching the 
strip above the hole and the bottom 
touching the platform edge. 
Connect your solar cells and 
motors back to the circuit. You're 

This project first appeared in MAKE Volume 12 . page 98. 

Related Posts on Make: Online: 

Giant Xylophone Table 

Solar Kit Gift Guide 

This document was last generated on 201 2-1 1 -01 09:43:34 PM. 

© Make Projects 

Page 13 of 13