Could use some general servo tuning advice. This is my first AC servo experience. Years of DC servo.

We have a 5axis trunnion, on a machining center. I have the 4th axis tuned and running. The 4th drive is a yaskawa SGDC-05AJA. (0.4kw) This series of drives does NOT have autotuning. Old school.

We are having problems tuning the 5th axis motor. The 5th drive is a SGDC-15AJA, (So a bit large at 1.5kw for the small motors) And have to use a 0.9kw motor code.

Could use some tuning advice. Out of the table, the 5th motor jumps wildly and alarms. Or is stable, but jumps when touched by hand, or when jogged 0.01°. Increasing position gain just causes the motor to oscillate and OVERHEAT. It is a brand new motor. When using the same parameters as the 4th, the motor just jumps/alarms consistently when energized.

I have the following tuning parameters:
Position Gain. Kp.
Speed loop gain. Kv.
Speed loop time Ki.
Speed torsion filter.
Load inertia.

The encoder output looks good, and I am getting good encoder position data on the control when spinning the motor by hand.

What gain parameters would you modify in order of priority? Once I get past jumping, and to oscillating, how much incrementally would you decrease position gain? 1, 10, 100, 1000? (Position gain currently set to: 4000. Speed gain: 4500. Time: 550.

What causes the servo energize, and wild jump? Too high speed gain, or too low position gain? Or some other gain parameter?