Differences Between Servo Motors and Stepper Motors

There are mainly two kinds of motors used in laser engraving machines, one is servo motor, the other is stepper motor, the two kinds of motor equipment have their own characteristics and are widely used in modern times. 

So, what are the specific differences between the servo motor and the stepper motor of the laser engraving machine? 

Firstly, The control precision of the servo motor is higher than that of the stepper motor. 

Secondly, the low-frequency characteristics are different, the low-frequency running stability of the stepper motor is worse than that of the servo motor in low-speed machining, and the AC power of the servo motor is more stable. 

Thirdly, in terms of overload capacity, the AC servo motor has a strong overload capacity, while the stepper motor generally does not have overload capacity. 

Fourth,(the output speed of the stepper motor is much lower than the servo motor, the speed of the stepper motor is unstable, floating between 300 and 600RPM, the servo motor is constant force output, 2000 or 3000RPM.). 

The output torque of the stepper motor decreases with the increase of speed and will decrease sharply at higher speed, resulting in its unstable operation, so the highest working speed of the stepper motor is generally in 300~600RPM. 

Ac servo motor is constant torque output, that is, it can output rated torque within its rated speed (usually 2000RPM or 3000RPM), and constant power output above rated speed. 

Fifth, the operating performance of the servo motor is different (the servo motor will not lose or overshoot, and the stability is high). The position ring and speed loop are formed internally, generally, the phenomenon of step loss or overshoot of the stepper motor does not occur, and the control performance is more reliable. 

Sixth, Different speed response performance (high acceleration start performance). 

It takes 200 seconds and 400 milliseconds for the stepper motor to accelerate from rest to working speed (usually a few hundred revolutions per minute). 

The AC servo system has good acceleration performance. Taking Panasonic MSMA 400W AC servo motor as an example, it takes only a few milliseconds to accelerate from static to its rated speed 3000RPM, which can be used in control situations requiring fast start and stop. 

Seventh, Control accuracy. 

In the case of low speed (usually 600rpm), the precision of stepper motor is as high as that of servo motor, while in the case of high speed (usually 1200 rpm), the precision of stepper motor is not as high as that of servo motor due to the drop of its characteristic torque. Stepper is used at relatively low speed, the servo is used at high speed. 

Eighth, control mode: stepper motor is open-loop control, there is no feedback, so the control is simple, only need to be equipped with a driver, the control part of the pulse; servo motor control is relatively complex. 

Finally, Price: stepper motor is much cheaper than servo motor.

Leave a Comment

Your email address will not be published. Required fields are marked *

twelve − one =

Ask For A Quote