Mirrorball rotator source of geared AC motor.

The humble mirrorball rotator is a very convenient source of a slow-turning synchronous geared motor. It's so mass produced as a product that it's often cheaper to buy a complete unit just for the motor.
These units are very useful as ornamental rotators for various objects besides mirrorballs. You can rotate signs, huge fake cogwheels or any other lightweight prop.
It's worth noting that the motors often have no specific direction. They will run in a random direction when powered up. They also reverse themselves when stalled.
The construction and windings are super-simple. A plastic bobbin for the windings and a metal plate on either side with interleaving fingers for the poles. The rotor is a permanent magnet, making the construction very similar to a stepper motor, but with just one AC winding. Applying current-limited DC to these motors makes them lock in their current position, a technique used in some motorised valves.
They can also be used as simple generators if not geared too heavily.
Being synchronous means they run at a precise speed based on the mains frequency. That means a motor will run slower on a European 50Hz supply than an American 60Hz supply.
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