Vibration in a kinetix 6000

I have a servo motor on a Kinetix 6000 drive that was previously working fine. It started vibrating (hunting) only when moving in rapid traverse at first. Now the axis will vibrate (hunt) at various spots and comes and goes. I tried to autotune it, but the software gets hung on "applying tune". Any ideas?

I'm not understanding "hunt". But anyways what is the application? Is the system multiple positions within a wide range of traverse? Carrying a load? What happens if servo is uncoupled? Does this servo motor have a brake?

If nothing changed in the digital servo amp, and the feedback device can be proven solid (look for noise errors, damaged cables) then it is likely the result of a mechanical problem.

I have seen some seemingly subtle problems with bearings and reducers result in symptoms like you've described.

If you have a mode in which you can jog the motor extremely slowly, you may find a spot in the feedback or load that is giving the positioner fits...

In most cases like these I have found alignment problems or other mechanical wear. I do remember one machine that only had trouble at a specific R.P.M. due to the wear pattern of the reducer.

You said "traverse". Is this a lead screw axis? I have seen worn ball screw servos act that way from being warped, or from having a very small area of wear that "trips up" the servo controller which suddenly starts overshooting or oscillating each time it crosses that change in load.

If it worked fine before and nobody changed any settings or programming, then I'll wager you'll find a mechanical issue...yes...that's a big, compound IF...