Opened up early this morning so I could have an hours play.
Adjusting the max error limits and dropping P I've got the following results:

X step response:


Dropped the P down to 1.5 which reduced the oscillation massively. I then increased error to 100,000 counts, and dropped it down until velocity was effected. Eventually settling at 1500 counts. I'm only using 1200 DAC bits max, so just over half of amp capabilities, but velocity is perfect for the lathe, the servo plot looks stable and servo oscillation is massively reduced.

Z step response:


Dropped P down to 3 and eventually ended up with a 600 error count which seems well enough. I'm only using half the amp capacity @ 1100 DAC bits, but again the drive sounds healthy and I don't need any more velocity. What do you think about the two above error plots Tom? Is there any reason why I have to use the full 2047 DAC bits? If the drives respond well, and error count is minimal I'd be quite happy sitting at 50%. What do you think.

Spindle step response:


Video @ http://81.138.85.180/~jim_cliff11/09...O-00000008.mp4

Reduced the P right down to 0.01 and increased until it became unstable. Settled with 0.07 which left me with a very slight, but gentle oscillation at commanded 0. Increasing error to 100,000 counts made a big difference, and I managed to reduce this to 12,000 counts. The command position and output plot above shows a MASSIVE improvement between between command and actual positioning. Any more than 100,000 counts/sec velocity caused the spindle to oscillate 2 or 3 times before dampening itself out at commanded 0. It'll be interesting to see what this equates to in RPM. Again only using 700 DAC bits, but by far I'm getting the best results yet with the above settings, so I might have to live with it. Unless theres any other tuning routes I can go down? Any thoughts overall Tom?



Not 100% sure how to perceive the above error plot, so I'll do some more reading tonight. Does it look reasonable though?

I've a link below to the spindle drive if it helps. I'm fairly sure it's speed control.

https://www.boschrexroth.com/country...KDA03_PRJ1.pdf
https://www.boschrexroth.com/country...IAX01_ANW1.pdf

Thanks,
Jim