Stepper motors are known to vibrate or resonate at certain speeds, particularly at low speeds. At low speeds, the motor's motion becomes more discrete, with distinct individual steps, and the rotor tends to oscillate back and forth between each step. This oscillation can excite mechanical resonance in motor components such as the rotor, shaft, and bearings. Resonance causes the motor to vibrate, resulting in a loss of torque and positioning precision.
While resonance is inherent to a given stepper motor and difficult to eliminate entirely, several methods can effectively reduce vibration.
1. Avoid the Resonant Speed Range
Since resonance only occurs within a specific speed range, avoid operating the motor near its resonant frequency. When accelerating through a resonant speed range, the motor should pass through it as quickly as possible to minimize vibration.
2. Increase the Microstep Resolution of the Driver
The higher the microstep resolution, the smaller each microstep becomes, and the motor's motion becomes smoother and more refined. This finer motion control significantly reduces vibration.
3. Reduce the Drive Current
While ensuring the stepper motor maintains sufficient torque, reduce the drive current as much as possible. Lower drive current reduces the magnitude of electromagnetic force changes between steps, which can help dampen oscillation.
4. Install Dampers or Shock Absorbers
Add a vibration damper between the motor and the mounting structure, such as a rubber or silicone coupling or a tuned mass damper. These components absorb the motor's vibration and reduce the transmission of oscillation to the system.
If the above methods still cannot meet your vibration requirements, you may need to consider a different motor or drive combination. Contact the STEPPERONLINE technical team with your required operating speed range, and we will help you select a motor whose resonant speed range falls outside your application requirements.