Another really cool 'motor' I have seen was used to make the flippers move on one particular type of pinball machine, sadly I forgot which one although from around the late 70's. It was an electromagnet about 1.5" in diameter with a shaft going through it. The shaft has a spiral groove which caused the shaft to have a rotary motion against a fixed pin protruding into the groove. The end of the shaft above the playfield had the flipper on it and the end of the shaft sticking below the 'motor' had a somewhat thick round disk on it that would be attracted to the electromagnet causing the flipper to move. In the schematic the device was actually called out as a flipper motor. At the end of the day, they really didn't work very well and didn't have a lot of power. A conventional solenoid flipper retrofit kit was soon released and those whacko rotary solenoid flipper motors went directly to the trash bin. I suppose an unmodified pinball machine would actually be a rare collectable these days??