FLOAT PIN FOR FOLLOWING ERRORS?

i have 2.88volts at 150 ipm. Should i edit my output scale in the INI? My rapids are 500 IPM which should be 9.6volts.

If the output scale is correct (machine units per second), FF1 should be 1.000
but nothing is ever exact so you always need to tweak a bit

Its arguably better to tweak the output scale (with FF1 = 1) but the main thing is to reduce the following error,
you will always have to hand adjust either FF1 or output scale to zero in on the proper value

Changing FF1 is having zero effect on following errors at 150 ipm.

Thats very odd since the error is proportional to velocity
changing FF1 should make relative large changes in the behavior

how are you changing FF1?

Can you post you hal/ini files? maybe there's a thread order issue or some setup problem,s

I close linuxcnc and edit and save the INI.

Argg... that's got to be painful!

I would test with halcmd so you can change the tuning dynamically

net x-vel-cmd => pid.x.command-deriv
you are connecting the signal x-vel-cmd to pid.x.command-deriv
but nothing drives net x-vel-cmd ( so FF1 is a no-op )

Simplest fix is to just comment out the
net x-vel-cmd => pid.x.command-deriv
net y-vel-cmd => pid.y.command-deriv
net z-vel-cmd => pid.z.command-deriv
lines:
# net x-vel-cmd => pid.x.command-deriv
etc

Good catch. I will update that now and let you know if that helps.

PCW wrote:

net x-vel-cmd => pid.x.command-deriv
you are connecting the signal x-vel-cmd to pid.x.command-deriv
but nothing drives net x-vel-cmd ( so FF1 is a no-op )

Simplest fix is to just comment out the
net x-vel-cmd => pid.x.command-deriv
net y-vel-cmd => pid.y.command-deriv
net z-vel-cmd => pid.z.command-deriv
lines:
# net x-vel-cmd => pid.x.command-deriv
etc

I believe pncconf does this, as I have the same lines in my config. I feel like changing FF1 would definitely affect my pid output, but I could be remembering incorrectly.

As a general rule, should they be left unconnected?
Are there any potential negative consequences to connecting pid.N.command-deriv to axis.N.joint−vel−cmd?
Same question for connecting pid.N.feedback−deriv to hm2_5i25.0.encoder.N.velocity?