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.