Online Step Motor Selection Tool

Unique algorithm uses voltage, current and speed to choose step motors

Al Presher, Contributing Editor — Design News

A free, online step motor selection tool, part of the Lin Engineering website called Designer’s Corner, simplifies the process of evaluating step motors. A unique aspect of the tool is that users are only required to specify minimal information including maximum operating speed, current and voltage to select an appropriate motor. Sign up to use this tool at

Lin Engineering is offering the first sample motor free of charge to the first 50 engineers who register for their Designer’s Corner, select a motor, and who mention Design News.

“Over the past 10 years, we have developed an algorithm that makes the specification process for step motors quite easy. Even though there is work going on in the background, the user inputs only the main components needed for the algorithm to work properly,” says Belal Azim, a Director of Sales and Marketing at Lin Engineering.

To use the tool, the user enters a maximum operating speed, maximum available current and voltage and the maximum desired dynamic torque required at operating speed. The system responds by displaying motors available that meet all of the basic specifications highlighted.

The Designer’s Corner step motor selection tool automatically generates torque curves for viewing online.

After selecting a motor, the system automatically generates a torque curve. Azim says that while the torque curve is not an engineer running a torque curve test in a laboratory it’s accurate to ±5 percent.

One goal of the system is selecting motors that maximize torque at the desired speed. Azim says it is common for motors to fail when applying the load to the motor because of lack of available torque.

“We use operating speed, and choose a winding that provides more torque at the operating speed because it is crucial to success of the application,” says Azim. “This process provides the most efficient motor and attempts to maximize torque at the operating speed.”

By editing parameters and generating a new torque curve, the user can view a new curve based on the new specification. Results can be printed or e-mailed to the user or a fellow engineer. They can also “request a quote” which takes them to an additional page which asks for quantity and target production date. A text box can be used to add details such as requirements for a shaft modification, information on system inertia or details about the load.