Click-Wheel Organ

Mechatronics engineering student Garett Morrison has been playing with homemade instruments and/or noise-making devices for years. As he puts it, “The gap between noise maker and musical instrument is wide, and [his] pile of out-of-tune prototypes continued to grow.” He finally seems to have found the solution, however, in the form of click-wheels, and managed to meld a number of them together into a unique electromechanical organ.

The concept is ingeniously simple: Each wheel is rotated on the same central shaft, which have a series of teeth cut into its circumference. Depending on the number of teeth on each wheel, the number that hit the reed per second, and thus the pitch, will be higher or lower at a given RPM. While the rotational speed and absolute pitch can vary (intentionally or not) the notes always stay in tune relative to each other. Since we perceive higher pitches as being louder at a given frequency than lower pitches at the same amplitude, the larger (higher pitched) wheels are cut with smaller teeth to equalize the perceived volume.

It’s perhaps exactly what you would expect a mechatronics engineer to come up with when inspired to design an instrument – which we of course celebrate here. Morrison even wrote a Python script to automatically generate the wheels, which are cut on a laser. CAD files, and the script are available on GitHub.

As for the resulting instrument, Morrison aptly describes it as sounding like a swarm of musical bees. You can see and hear this ingenious spinning instrument in the video below.