It is vital to select the right motor for your applications. It can be difficult for a servo or stepper motor to be chosen due to so many considerations, including cost, torque, efficiency and speed.
It helps to first know what makes these motors different and which pros and cons each has. You can then match the motor's capabilities to your application.
Different Servo Motors & Stepper Motors for Motion Control Applications
The major difference between these motors lies in the overall pole count. The pole count of stepper motors is usually high, often between 50 to 100. Servomotors, on the other hand, have a low pole count of between 4-12.
This difference in the pole count makes stepper motors work incrementally, with a consistent pulse in closed loop systems. An encoder can adjust pulses in a servomotor for position control.
Stepper Motors In Motion Control: Because of their high pole count they offer precise drive control in motion control applications. They provide a high torque at low speeds and are inexpensive and easily available.
Stepper motors can have their limitations. They lose almost all of their torque at high speeds. Sometimes, as much as 80%. They produce high vibration levels and can be susceptible to resonance issues. Additionally, stepper motors produce high heat levels which can pose a problem in some applications.
Servo Motors In Motion Control: What are the Pros And Cons? The main advantage of servomotors is that they can deliver high torque at high speeds, which stepper motors cannot. They can also achieve 80 to 90% efficiency. Servomotors can be used in AC or DC drive and are immune to vibration and resonance.
Servomotors have many benefits but are generally more expensive than stepper. Add to this the expense of an encoder (and often a manual gearbox), and the system can be quite costly. A gearbox and encoder make the system more difficult, leading to increased maintenance and higher costs.
Each motor comes with its pros and disadvantages. The differences between servo- and stepper motors can help align your application with the correct type of motor.Tags: stepper motor