Modifying a stepper motor by drilling a hole down its shaft ... the coil roller in contact with the paper. A real-time coil winding session starts at the 21:18 mark, and we’ve got to admit ...

[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 ...