Printed stepper motor
The motor below was printed using Proto Pasta's Iron-doped PLA, which has a relative permeability of around 10.
This directory contains STLs and a Fusion design file.
Be warned -- there are a few crucial design errors! First, the tooth size is too small given the reduced relative permeability of this filament, as compared to magnetic steel (\mu_r \approx 1000). Second, while the two magnetic poles have a full tooth offset, the two electrical phases don't have a half tooth offset. Duh! So, even if the tooth size we correct, the stepper wouldn't step in a predicatble direction. Someday I'll fix these and print another...