CD/DVD drives are a great source of interesting scavenged components - in particular laser units and stepper motors.
I pulled some of the head control stepper motors some time back. They are small 4-wire bipolar stepper motors with a worm drive for linear motion. Datasheets are non-existent(!), so this is a little project to figure out their specs and demonstrate driving the units with an Arduino and bespoke H Bridge control circuit.