I have an unknown 4 pole (I think) servo motor with a 1024PPR encoder attached to a milling machine spindle with a toothed belt. I’m using an Argon servo drive. I’ve tuned the torque parameters to a good fit with the expected curve by clamping the spindle in the machine vice and going through the guide on the wiki.
I’m now having trouble tuning either velocity or position modes and was wondering if anybody has some tips, or whether there are inherent issues in my setup. I’m not at the machine right now so I can’t post config/tuning screenshots but will do if they help. My questions (if I may be greedy):
- Does the slight elasticity in the belt and the inertia of the spindle cartridge make tuning the servo harder/impossible?
- If I change the magnetic pole count to a number other than 4, the motor stalls. Is 4 a sensible amount of poles, or is something really messed up in my motor? It’s a second hand eBay special so documentation is nonexistent.
- Is 1024PPR (4096 pulse quadrature) accurate enough for a spindle with orient ability?
- Even with an acceleration of
1set, both the commanded velocity and position are impossible to tune to the orange “set” line on the scope graphs. I’ve tried all sorts of values, most of which make the motor squeal and squawk. If I tune it so it’s quiet again, I get lots of overshoot, etc.
- I clamped the spindle to stop it moving when I torque tuned it. Again, there’s slight elasticity in the belt between spindle and motor. Does this affect torque tuning? Would that affect position/velocity tuning?
I’ve been struggling with this on and off for like 3 days now so would appreciate some help or tips, or something obvious I’m not doing. Happy to provide more details later - I can get the config and some screenshots when I’m next in the shop. Has anyone else had problems tuning spindle motors before? It’s a BT30 spindle and the motor is rated at 380V/12A. I’m feeding it about 300V/10A which should give me plenty of power.