My control theory (PID loops etc.) is long forgotten it was 40 years ago. My understanding is that ac servos are a bit more finicky to tune than dc servos partially because they have wider bandwidth (they maintain their torque at higher speeds better than dc servos)
Hopefully this thread can help guide future ac servo tuners. I realize there are a lot of clearpath fans out there (they keep reminding me of how effortless it was to get their servos tuned), that's great but is probably not relevant to this discussion.
Application is CNC conversion of a 8x30 knee mill with 5mm pitch ball screws installed (16mm for X axis and 20mm for Y axis).
Rough guess on weight is:
X: 125lbs unloaded and say max of 200lbs loaded
Y: 175lbs unloaded and say max of 250lbs loaded
Everything is mounted, connected and working with very preliminary tune. I'm focusing on fine tuning the X-axis at the moment
I'm using StepperOnline T6 750W ac servos with a direct drive (1:1) configuration using compliant couplers. With very preliminary tuning they move the table silently and effortlessly at 40-80 ipm, I will likely limit rapid to 40 or 50 ipm fast enough for me.
The only setting I have tweaked so far is Inertia ratio, the default setting was 200 and this caused the move to oscillate at the destination, I kept tweaking the value up and the end point oscillation kept diminishing. with the value set to 800 it seems quite stable now.
The next critical setting is stiffness, and after that there are about a dozen other fine tuning parameters.
If you have any experience to share, I'm all ears and eyes and if you have any good links on the subject please pass them on. If someone has actually tuned either the Leadshine or StepperOnline servos that would be most helpful
Thanks in advance