Servo Wiring and Tuning detailed How To example Mesa 7i77.

Amazing how-to, thanks, great starting point for me.

I find this video with a basic overview of the tuning method to provide quite supplementary information

Ziegler-Nichols Method

In halscope what are the units ?
For example if set f-error to 200m/div what and i see 1 div how this translates to mm ?
Also in cmd-velocity if i set to 1/div how this translates to mm/sec ?

I have seen a post by @andypugh that showed an alternative method of pid tuning
know anyone the link of this post ?

If the machine uses mm units, 200m = 0.2 mm/division
and a velocity of 1 means 1mm/s

I would need a bit of hint on my tuning of AC servos + 7i95t, as I cannot decrease those spikes on acceleration and deceleration, doesn't matter if I go higher or lower with FF2. On linear move there is f-error 0.001mm or less. Should I start adjusting parameters on diver?
Also if I "go crazy" with short presses on arrow keys for jog, especially with changing direction, f-error is all the way up to 1mm or more.

Captures below are taken during running some test g-code:
 


 

 

Are these step/dir servos with encoder feedback to LinuxCNC?

If so it seems there is significant delay from command to motion.
This may well be a drive tuning/setup issue. Maybe drive acceleration
set lower than LinuxCNCs setting or some other filtering or constraints
in the drive.

If those are step/dir drives, you should be looking here:
forum.linuxcnc.org/10-advanced-configura...glass-scale-feedback
Also
dirsetup and dirhold to 20000
and stepspace and steplen to 5000
Untill you get things working properly, then you can lower the steplen and stepspace while testing to make sure there are no missed steps.
As you have them, chances are some steps are being missed by the drive so LinuxCNC keep upping the number of steps till it catches up.
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Yes, i am aware the drive manual might say 200ns, but that is almost always not correct, except on very good quality drives.