Important components of laser cutting machines and laser welding machines, servo motors or stepper motors are common types of motors used in various applications, but they work in different ways and have different characteristics. Here are the main differences between servo motors and stepper motors
Control System:
Servo motor: operates based on a closed-loop control system. It uses feedback from an encoder or resolver to continuously adjust and control position, speed and torque. The controller adjusts the input signal to the motor to maintain the desired output.
Stepper motor: operates based on an open-loop control system. It receives electrical signal pulses that move in discrete steps. There is no feedback mechanism to verify the actual position of the motor, it is assumed that each pulse results in precise movement.
Feedback system:
Servo Motors: Requires a feedback device such as an encoder or resolver to provide information about the actual position of the motor. This feedback enables the control system to adjust precise positioning in real time.
Stepper motors: often lack feedback systems. It relies on the assumption that each pulse sent to the motor causes a specific movement, but does not directly verify the actual position of the motor.
operate:
Servo Motors: Provide continuous rotation and precise control of speed, position and torque. It is ideally suited for applications requiring high precision and dynamic performance.
Stepper motor: moves in discrete steps, making it suitable for precise positioning applications. However, it may not provide the same level of speed and dynamic performance as a servo motor.
Static torque:
Servo motors: Typically have lower torque at rest compared to stepper motors. If torque must be maintained while stationary, an external holding brake is required.
Stepper Motor: Provides holding torque at standstill without the need for an external brake. This feature makes stepper motors suitable for applications where the load needs to be held in place during a power outage.
Complexity and Cost:
Servo motor: generally more complex and expensive due to the need for a closed-loop control system and feedback device.
Stepper motor: Typically simpler and more cost-effective because it operates in an open-loop system and does not require a feedback device.
To summarize, the choice between servo motors and stepper motors depends on the specific requirements of the application, such as accuracy, speed, cost, and complexity. For applications requiring high performance and precision, servo motors are often preferred, while stepper motors are suitable for simpler applications where cost constraints are lower.