PROJECTS: SOLAR XYLOPHONE
4c. 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 error.
4d. 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.
4e. Hold the motor slightly offset from the mallet, and make sure
the motor is oriented so that it will pull down on the mallet.
4f. 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.
4g. 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 place.
4h. 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.
106 Make: Volume 12
NOW GO USE IT »