We’ve seen plenty of motor projects, but [Jeremy]’s DIY Tubular Linear Motor is a really neat variety of stepper motor in a format we certainly don’t see every day. It started as ...

Figure 2 Varying the reference voltage instead of the R-C time-constant gives a tuning law that is close enough to being linear in pitch over a couple of octaves, especially after adding R2. Just as ...

To drive the coils, he used a pair of TB6612FNG stepper motor drivers, controlled by a Wemos D1 Mini. The housing was 3D printed mostly from PLA, but with a few bits done in PETG. This was for ...