Sound controls

This organ found was made with python and a laser cutter

Some of our readers will no doubt remember attaching a playing card to the front fork of his bike so that the spokes clicked the card as the wheel spun. It was supposed to look like a motorcycle, which it wasn’t, but it was fine, clean, and fun with the added bonus of making us even more annoying to the retirees in the neighborhood than the normal baseline, which was already quite high.

[Garett Morrison]”Click Wheel Organ” works on the same principle as a card in the spokes, but with many more wheels and much more musicality. The organ consists of a separate toothed wheel for each note, all rotating on a common shaft. Each wheel is laser cut from thin plywood, with a series of fine teeth around its outer circumference. The number of teeth, as calculated by a Python script, determines the pitch of the sound emitted when a thin reed is pressed against the spinning wheel. Since the ratio of the teeth between the wheels is fixed, all notes remain in tune with respect to each other, as long as the speed of the wheels remains constant.

The proof of concept in the video below shows that velocity control isn’t there yet – playing multiple notes at the same time seems to increase drag enough to slow the wheels and lower the pitch of all notes. There appears to be a photo switch on the wheel shaft to monitor speed, so we imagine a PID loop to control motor speed might help. That and a bigger motor that doesn’t bog down as easily. As for the sound, we’ll just say it’s certainly unique – and sounds like something [Nicolas Bras] would really dig.