There are clear differences between stepper motors and servo motors in several ways.
Control mode: The stepper motor controls the rotation angle by controlling the number of pulses, while the servo motor controls the rotation angle by controlling the length of the pulse time.
Workflow: The stepper motor generally needs two pulses, the signal pulse and the direction pulse, while the workflow of the servo motor is a power connection switch, and then the servo motor is connected.
Low-frequency characteristics: stepper motors are prone to low-frequency vibration at low speeds, while servo motors run very smoothly and do not vibrate even at low speeds.
Torque frequency characteristics: the output torque of the stepper motor decreases with the increase of speed, and will drop sharply at higher speed, so its maximum working speed is generally 300 600r min. The servo motor is a constant torque output, within its rated speed (generally 2000 or 3000 r min), the output of the rated torque, above the rated speed is a constant power output.
Overload capacity: Stepper motors generally do not have overload capacity, while servo motors have strong overload capacity.
Accuracy: The accuracy of the stepper motor is superior to that of the servo motor, and there will be no accumulated error, and generally only open loop control is required. Servo motors are superior to stepper motors in terms of responsiveness.
Speed: It takes hundreds of milliseconds for the stepper motor to accelerate from a standstill to the working speed, while the acceleration performance of the AC servo system is better, generally only a few milliseconds, which can be used for control occasions that require fast start and stop.
Stability: The stepper motor generally does not lose steps, which is convenient for control. The servo motor, especially the low-end servo motor, has an inaccurate speed and is inconvenient to control and operate.
In general, stepper motors and servo motors have their own characteristics and need to be selected according to specific application scenarios and needs.