Brushless DC motors are common place in RC Vehicles ... This shaft size was important because the motor shaft was to be replaced with an ER16 collet arbor of the same size. A collet is a device ...
How to Make a Generator Using DC Motors ...
[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 ...