Robotics/Stepper Motors

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 Coil - 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 - ...

What's a stepper motor?

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.