Having finally got my Bridgeport conversion up and running, i got to fine-tuning.

I did a home-all tonight and noticed the X axis was wobbling when doing the back-off part of the home sequence so it seems my inept attempt at auto-servo tuning was lacking somewhat. In the graph i could make it do the wobble-thingy at about 13% speed and it looked bad.

Reading the CSMIO manual, the tuning section is a bit vague but it seemed i needed to reach oscillation first then back off. Having seen what that does, i thought it safer to tune for the lowest following error and fastest dead-band arrival as i had read on various other papers, there does not seem to be any "scientific" method to tuning, just get it smooth, fast and oscillation free.

Tweaking the values in P-I-D order, i have now got far better following errors and as yet no wobble;)
Values are now...
X P=20,000 I=50, D=0, ff=65 Following error 135 at max speed
Y P=20,000 I=50, D=0, ff=65 Following error 105 at max speed
Z P=12,000 I=65, D=0, ff=60 Following error 253 at max speed

These errors are much lower than before and it seems happy at all speeds now so will leave it there for now.

Is there any advice for tuning or is it all suck-and-see??