Rotarty car hanger project. Project URL: http://www.instructables.com/id/Rotary-Car-Parking-System/
Features are: Adjustable motor speed (RPM). Changeable Steps per revolution value for any bipolar stepper motor to be used. (Though 200 spr or 1.8 degree step angle motor is preferred). Adjustable number of stages. Individual shift angle for every stage (thus any error in manufacturing can be programatically compensated). Bidirectional movement for efficient operation. Settable offset. Storage of setting, thus adjustment required in first run only.