This quadruple list describes the modular form of exertion instruments. It has four main components: 1. The mechanical movement. 2. The electrical conversion type. 3. The processing. 4. The output, including speaker and resonating hardware. These modules can be combined in a large number of ways. Perhaps only several will survive as viable instruments.
The first exertion instrument is simply a speaker electrically and physically connected directly to a stepper motor.
Various extensions can be used to stimulate the motor to generate electricity. Each has a different effect. This simple crank doesn't spin well, but makes a fast decreasing envelope.
The envelope was good for making a disco pitch sweep sound.
action shot.
Next, I wanted something I could hit with a mallet, so I tried a tri-spoke design. This one was homemade from hex stock with rebar welded to it. It was the hex stock was tapped to allow set screws to adjust to a large selection of motors.
The tri-spoke mounted on the generator/motor.
The spoke spins much better (faster and longer) than the assymetrical crank.
It was clear that weight/moment of the spokes is key, so four sizes were made. They are modular and can be quickly switched using a philips screwdriver. The next step will be to experiment with a familiar wheel. Because of the way it's played. It's easier to strike a moving wheel then the moving spokes.
the motor itself is held on simple with two bolts...
after many trials by myself and others, I decided to try another motor - one with internal gearing-up, so that it wouldn't spin as long, but faster internally, generating a higher voltage for a shorter amount of time. This motor has been mounted, but not tested yet.
meanwhile the same speaker has the generator mounted on the other side for better playability. The shorter spokes are better for drum sounds because it has less momentum and is easy to start and stop than the longer tri-spokes.
front view showing dual motors. Each motor could be mapped to a drum sound each.
This experimental electronics setup was the first to use the generator to run a Number Six/Atmega32 microcontroller and amplifier. The software is a simple drum synthesizer.
This is how the "Two Drum" prototype looks. Note, knobs from controlling drum synthesizer parameters, similar to classic TR-808, TR-909 drum machines.
Player's view: the speaker faces outward. The speaker has taken lots of damage...
This is a block diagram of the circuit: motor, power regulation, microcontroller and amplifier.