Cincinnati Millacron X axis slide

jlviloria wrote:

the machine moves well, although I have not managed to move 10000mm/min. I've only come to 7000mm/min. when 7000mm/min move faster than I get a warning in the "servodrivers".

This almost certainly has nothing to do with the PID tuning. It may be that you need a lower max accelleration. Looking at a Youtube Video it looks like the machine has a very heavy X-axis slide.

I do not understand that the input and output units of the PID?

The PID has two inputs (position-cmd and postion-fb) and one output.
Depending on the source of those inputs, and where the output goes to (in HAL) their units can be very different, and the optimum Pgain (etc) can vary by many orders of magnitude.

You may well want some Dgain, but that will need to be very small relative to Pgain. If Pgain is 5 then I would expect the correct Dgain to be 0.0005 (maybe 10x smaller or 100x bigger)

However, your f-error doesn't seem all that bad, if the units are mm. 20um error at the acceleration peaks?

jlviloria wrote:

when you say 20um. mean. 20 micrometros?

Yes, I couldn't work out how to type 20µm at the time. (I did manage to find a way to turn my screen upside-down though...)

This also confuses me. the idea is to produce parts with good accuracy and repeatability. 0.02mm settings. f-error is perfect or need minus?

0.02mm is not very good for lathe precision, but your steady-state error seems to be very much lower. (0.002mm) and that is the state the machine will be in during slow machining operations. (in fact, in the vast majority of lathe machining operations the critical axis is completely stationary).

I suggest that you leave the tuning for the moment, and see how the parts turn out.