Servo Tuning

I'm back after a extended work break.

I need to solve this issue so i can get the machine up and running. I'm going to put the next few days aside to get it finally running.

The one servo runs away with a step input.

I have a youtube clip of the problem and attached screen dumps of the setup.

Youtube Linux CNC









Any help will be appreciated.

To me it looks like either the acceleration is too high for the large jog steps (causing a large following error) or the P gain is too high (or D too low if these are torque mode drives),
causing ringing when you jog.

Also tuning bare motors is different (and usually more difficult)
then tuning motors with a full inertial load.