Stepper motors are digitally controlled drives that became popular when the change from analog to digital occurred. Ranging in sizes 15 to 100 millimeters in diameter with variable length and torque, they're used in a wide spectrum of common drive and positioning applications. A stepper motor can be a good choice when controlled movement is required. They can be used to advantage in applications where rotation angle, speed, position and synchronism need to be controlled.

Industry uses stepper motors on automated assembly lines and in industrial machines. They're also part of our everyday lives. Some of these applications include hard disk drives, fax machines, printers, scanners, CD players, auto gauges and cruise control. Stepper motors have the following advantages over other types of motors:

1. Inexpensive compared to other motion control systems

2. Excellent low speed torque and can drive many loads without gearing

3. Easy to set up and use most stepper motors

4. Long product life because a stepper motor has no contact brushes

5. Low control requirements

Action Steps
The best contacts and resources to help you get it done

Compare products offered by stepper motor manufacturers

When choosing a stepper motor, the number of rotations (steps) per minute determines the precision of the motor. The type of winding scheme, the driver and the torque required are also important factors to compare. Check out a stepper motor forum online for tips on which models offer the best performance.

I recommend: Ledex-Johnson Electric is a certified manufacturer of all types of stepping motors (including rational and linear) with varying torques. Industries served include business machines, heating ventilation, air conditioning, industrial equipment and automation, leisure, fitness and medical equipment. M Squared Electronics is a stepper motor supplier of full step, half step or fractional stepping motors for industrial and commercial applications. For a stepper motor forum, check out Eng-Tips.

Purchase a waterproof stepper motor or a submersible stepper motor

Waterproof stepper motors are used in applications where splashing or chemical spills might occur. Fully submersible stepper motors are used in water applications.

I recommend: Bearing Industrial and Supplies is a distributor of stepping motors, including waterproof stepping motors. Lin Engineering offers a submersible stepper motor from depths of 15 centimeter to 1 meter. Lin also offers a dust proof, water resistant stepper motor driver that's protected against damaging environmental elements.

Find a micro-stepper or miniature stepper motor for an electronic application

Some stepper motors are designed specifically for micro-stepping and have tighter machining tolerances on the teeth. Miniature step motors are used in telecommunications, hobby and quality modeling, as well as optical, video and audio applications.

I recommend: WZ Micro offers several low cost miniature step motors for computer drives. Oriental Motor USA offers five and two-phase micro-step packages with programmable drives and controllers.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  Stepper motor applications are designed to run hot. Most have class B insulation, which means they can sustain temperatures up to 90 degrees C without thermal breakdown occurring.
• •  The right stepper motor control software can make stepper motors just as fast or faster than many servo systems.