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CS-Lab / PID Tuning, one axis perfect, the other causing a headache.
« on: July 21, 2016, 02:32:06 PM »
A brief background,
I've started another thread talking about retro fitting a ROMI lathe with mach3 , which had Bridgeport EZ PATH on. I've used a CSMIO A type to drive the existing hardware, brushed DC servo motors with encoder feedback going straight to the CS module.
Last night I very quickly tuned the Z axis which is being driven off the existing servo amplifier 100v DC. Smooth, no hunting, repeats accurately, everything is great.
Today I received a new servo drive for the X axis as the old amp died. It's an Axor MCS 110 6/12amp.
After wiring it in I'm struggling with the tuning config. After auto tuning several times the best I can achieve still leaves very slight ocilation/hunting and next to no rigidity. By that I mean I can twist the ballscrew pulley from 11 o'clock to 2 o'clock with little resistance. The motor screw ratio is 1:1.5, 6mm pitch b/screw, but it is a proven system from the previous control incarnation.
I thought the axis using the 20 year old servo card was going to be the issue, not this one with the modern drive!
Any suggestions greatly received.
I've started another thread talking about retro fitting a ROMI lathe with mach3 , which had Bridgeport EZ PATH on. I've used a CSMIO A type to drive the existing hardware, brushed DC servo motors with encoder feedback going straight to the CS module.
Last night I very quickly tuned the Z axis which is being driven off the existing servo amplifier 100v DC. Smooth, no hunting, repeats accurately, everything is great.
Today I received a new servo drive for the X axis as the old amp died. It's an Axor MCS 110 6/12amp.
After wiring it in I'm struggling with the tuning config. After auto tuning several times the best I can achieve still leaves very slight ocilation/hunting and next to no rigidity. By that I mean I can twist the ballscrew pulley from 11 o'clock to 2 o'clock with little resistance. The motor screw ratio is 1:1.5, 6mm pitch b/screw, but it is a proven system from the previous control incarnation.
I thought the axis using the 20 year old servo card was going to be the issue, not this one with the modern drive!
Any suggestions greatly received.