Yesterday my 1-1/2 year old 1100M developed a Y axis groaning/growling noise. Thought for sure it was a bad ball nut the way it sounded. First I checked the ball nut bolts, the coupling bolts and the motor mount bolts. All were tight. There was no visual damage to the portion of the ball screw that I could see. On a whim I shut the machine down and restarted it and the noise went away. That was temporary as it did come back after a few minutes of machining time. Repeated the shutdown/restart and no noise until I ran a tool path. I'm now thinking it could be control related. I shut down and opened the electrical cabinet and did a visual inspection paying attention to the Y axis driver and wiring. Disconnected the wire connector and didn't notice anything unusual. Reseated the connector and made sure it was properly seated. Checked the Y axis wiring terminations to make sure they were tight. Started the machine and the noise comes back after a few minutes of run time. No lost steps that I could determine. X and Z axis are fine; smooth and quiet. That's the history.

Anyone experience this type of problem? Could it be a bad driver?