If you have a junk box full of all sorts of motors from printers, scanners and other discarded tech you need to know what you have so you can use it in your next project. Thanks to Steaky for sending in this info that was written to help you determine what type of stepper motor you have and how to use it.
“Not only do stepper motors come in a variety of shapes and sizes, they also have different coil configurations. This can help identify how to drive the stepper motor, and what sort of controller you are likely to need to drive the motor. Stepper motors typically have 4,5,6 or 8 wires, and these can be used to identify the type of motor. There are two types of stepper; Unipolar and Bipolar. This refers to how each coil is driven. A unipolar stepper only requires each coil to be driven in one direction, whereas a bipolar requires driving in both directions.”