Project 70
Spin Draw
Project 71
Singing Motor
The motor has a coil and a magnet similar to the
speaker. An electrical signal in the coil creates a
magnetic field, which makes the shaft spin.
Normally the motor is used with a stable
electrical signal, but in this project it is used with
a changing signal from the space war IC. This
creates mechanical vibrations, which create air
pressure variations that sound like the speaker
does, though not as efficiently.
Rebuild the simple motor connection as shown on the left. This is the same setup as Project 66.
Setup:
Cut out a circular piece of thin cardboard from the back of an old spiral notebook or note
pad. Use the fan blade as a guide. Place the fan on the cardboard and trace around it with a pencil
or pen. Cut the cardboard out with scissors and tape it to the fan blade. Do the same thing with a
piece of white paper, but tape the paper on top of the cardboard so it can be removed easily later.
Drawing:
To make a ring drawing obtain some thin and thick marking pens as drawing tools. Spin
the paper by pressing and holding press switch (S2) down. Press the marker on the paper to form
rings. To make spiral drawings, release press switch (S2) and as the motor approaches a slow
speed move the marker from the inside outward quickly.
Change the colors often and avoid using too much black to get hypnotic effects. Another method is
to make colorful shapes on the disc then spin the disc and watch them blend into each other. When
certain speeds are reached under fluorescent lights without electronic ballasts, the strobe principle
shown in another project will produce strange effects and backward movement. Make a wheel with
different colored spokes to see this strange effect. Adding more spokes and removing spokes will
give different effects at different motor speeds.
Turn on the switch and the motor spins (you may need to give it a
push with your finger to get it started). The sounds from the IC are
used to drive the motor. Because the motor uses magnets and a coil
of wire similar to a speaker, you may even hear the space war
sounds coming faintly from the motor.
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