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Stepper Motor Basics 
- Degree of Rotation - Every stepper motor has a degree of rotation. This value indicates how far the rotor will spin around it's axis for each signal sent.
- Number of Coils - These motors drive coils in a pattern to advance the rotor position
- Driving a Coil - This is done by passing current through the coil. In stepper motors, all coils must be driven in both directions over a complete revolution.
- Sequencing - These motors require the electronic control to change which coil in being driven at the correct time. Without this the motor will hold in one position.
- H-Bridge Style Driver - ...
In robotics stepper motors are primarily used in stationary robots as they tend to consume quite a lot of power. They are ideal for movements that have to be accurate and are larger than 180°.
Common Uses/Part Sources 
- Floppy, hard disk, or CD/DVD-ROM drives - The heart of most these is the stepper motor. In most of these drives, there are two stepper motors. They position the read/write heads and they spin the medium.
- Printers, scanners, plotters, and copy machines - Most of these devices utilize stepper motors. They are used primarily to position the print head or optics on an (X,Y) coordinate system. One motor positions on the X axis and the other positions on the Y axis.
- CNC machines, routers, scanners, lathes etc - Used for X/Y/Z positioning of heads.