Getting the Right Stepper or Servo Motor for Electric Actuators As usual, the needs of the application play a major role in determining which is the best type of motor to use.

As the shift to automation continues to gain momentum in the industrial sector, servo motors and stepper motors with electric actuators become ever more important. When selecting a motor for an application, it is the functions that are important, not necessarily the construction.

Here’s a look at servo and stepper motors’ characteristics as they relate to linear motion. (Brushless DC motors will be considered servo motors for this article.)

Torque vs. Speed

Servos have a constant torque over their total usable range of speeds. So, if a servo motor has 1.2 Nm of torque at 10 rpm, then it also has 1.2 Nm of torque at 3,000 rpm.