Servo Wiring and Tuning detailed How To example Mesa 7i77.

Sounds like is it running in torque mode ( are there tachometers at all? )

There is a "TACH" input on the driver, but I don't have anything connected to it, and I checked the old ribbon controller that was connected to the old controller and the TACH pin wasn't used either. Only thing coming from motor is Power and Encoder (i believe) and brake for Z.

Having difficulty finding any servo tuning information on servos operating in TORQUE mode. Does anyone know of any tuning resources for me?
Thanks

A _very_ rough guide is this (for a single PID loop/Axis)
Start with FF1=0 and FF2 = 0 and I=0

Chose a small amount of P (say 50 = full torque with 1/5" error)
Then increase D until it gets too "buzzy" and then back off about 30% on D
Then increase P until you get oscillations and again back off about 30%
Then adjust FF2 so that you neither overshoot or undershoot during
acceleration (the FF2 setting is inertia dependent so its better to do this with a typical table load)
Finally increase I until motion becomes unstable (Watch out for WIDE oscillations here)
and back off about 50%

Is any of this still valid?

gnipsel.com/linuxcnc/tuning/torque.html

JT

Its still valid (just more conservative)