Stepper motor for computer numerical control machines CNC Wood Router using

Stepper motor for computer numerical control machines CNC Wood Router using 

Types of stepper motors

This is just a simple overview of stepper motors and I won't go into details about all the numerous different varieties you'll find. A couple of technical terms that are worth knowing crop up often in the literature (and in web pages) about stepper motors, often without any explanation.

Poles

The motor I've illustrated here has a rotor magnet divided into lots of alternating north and south poles, so this design is known as a multi-pole motor. The more poles, the shorter the distance the motor rotates on each step and the more precisely it can be controlled.

Phases

In a motor, a "phase" usually means one or two opposing electromagnets that operate alternately (out of sync with one another or out of phase, if you prefer). The motor I've illustrated up above has two phases (two pairs of electromagnets, so four electromagnets in total, arranged at 90 degrees). In a three-phase stepper motor, you might have three electromagnets arranged at an angle of 120 degrees (so three individual electromagnets, although a three-phase motor could also have three pairs arranged 60 degrees apart). A four-phase motor has eight electromagnets arranged in four pairs, with each one separated from the next by 45 degrees.