Source of Abnormal Noises in Servo Motors
If your servo motor whistles, hums, or makes a grinding noise while running, do not ignore it. Motor noises generally fall into two categories: Mechanical and Electromagnetic.
1. Mechanical Noises (Bearings)
If the sound is a grinding noise, the problem is likely shattered bearings. Bearings that run dry or suffer from unbalance scratch their raceways and create terrible noises at high speeds.
2. Electromagnetic Humming
If the motor makes a high-pitched whistle or hum even while standing still (but energized), it might be an encoder issue. A dirty encoder causes the drive to constantly correct the motor position in micro-angles (hunting), which sounds like a hum.
What Should You Do?
Continuing to run the motor will cause a locked bearing or burnt stator. Send humming motors to the Code Elektronik Mechanical workshop for bearing replacement and encoder calibration.