There are a lot of fun projects you can do with stepper motors salvaged from ... which won’t do anything to drive the motor. Others have a case ground wire. Steppers have either 4, 5, 6, or ...

[Frank Herrmann] had an interesting idea to turn a geared DC motor into a servo motor assembly, but with a stepper motor-like interface. By stacking some small PCBs behind the motor body, it was ...