Prototrak Plus Retrofit with Mesa 7i77 & 5i25 cards

Thank you, Andy!!

I have turned each of the variables (paid special attention to the P,I,D,Deadband,FF2,FF1), in that order, more so the 1st of the 3 (P,I,D) until there was noise (admittedly low noise that would settle down, quickly, some appeared to come and go, when I would revisit a prior setting that was known) but what you see is what I could tune "pid.n.error" to around "x axes" f(.095)=.0272 (ddt -.054) and "y axes"f(.085)=.0258 (ddt -.0182), see below:


I know this is not what is required, I will try some more tuning. If the plus side of the duel loop is to limit the velocity, I can see how wonderful that would be. If there is any thinking about the tuning of AMC amps I could review that if necessary, like say more amps would help. Your comments and suggestions are warmly welcomed.

Many, many thanks!!

new2linux wrote: Thank you, Andy!!

I think you mean to thank Todd....

That does not look to me like the plot of a torque mode servo. I think your drives may be using some voltage feedback from the motor to fake velocity control. That is a good thing though.
It does look like you need to do some tuning on the drive itself. See how, even with a very high pid.N.output the acceleration is constant and linear, but way less than the commanded acceleration. You either need to adjust the tuning of the drive (this is in the drive not in Linuxcnc) so that it can accelerate the motors at least as fast (preferably a little faster) than you are commanding them in Linuxcnc. These adjustemets will likely be with trim pots on the drive or with a software program provided by the drive manufacturer. If you can't improve the drives performance, then reduce your max acceleration for the joint in Linuxcnc to something less than the drive is capable of.

Which drives did you end up getting?

Andy, what can I say? I have read so many threads.
Todd, I am very thankful for you taking time to help!! Thank you!
the amps are AMC Advanced Motion Control, Brush Type, this is link to pic; forum.linuxcnc.org/media/kunena/attachments/21712/IMG_1001.JPG

www.a-m-c.com/wp-content/uploads/support...ual_Analog_Panel.pdf

this is a manual for setup.

thanks!!

As I recall he got drives that only accept tach, (+=10volt), feed backs. But his motors are fitted with quad encoders. I'm pretty sure about it, but...

ADDED: So the amps may not be set properly to torque mode????

Best, Dan.