Lagunmatic 3516-SX Retrofit

andypugh wrote: I think you might be seeing I-term windup if it oscillates. Does it still oscillate with an I-term of zero?

My methodology was to start with all zeros and first determine an appropriate P value. P=0.125 (everything else zero) will oscillate and the error curve is essentially a stable sine wave. It will never converge in this condition.

If I remember correctly, lowering the P from there would mean sometimes the spindle wouldn't move at all.

I didn't see any convergence until I started adding an I value.

I think for spindles you should always start with FF0=1 only

For a velocity command input, velocity PID output loop FF0 =1 means you start with the PID output just following the command. If all other PID parameters are 0, this is open loop but it should be close. Next the P and I term values can be added to correct any deviations in the open loop control

PCW wrote: I think for spindles you should always start with FF0=1 only

For a velocity command input, velocity PID output loop FF0 =1 means you start with the PID output just following the command. If all other PID parameters are 0, this is open loop but it should be close. Next the P and I term values can be added to correct any deviations in the open loop control

Does this still apply if I am trying to control the position of the spindle instead of the velocity?

I experimented with the FF0 values in the .90 to 1.0 range and didn't see much of a benefit

No, for position control but velocity PID output (to VFD in this case), you want FF1 = 1.0 and typically FF0 =0

PCW wrote: No, for position control but velocity PID output (to VFD in this case), you want FF1 = 1.0 and typically FF0 =0

I'll add these tonight and see how it affects the performance. Thanks!

Haven't had a chance to implement the suggestion above yet. Between the building of my new place, trying to move my parents, and other life stuff just haven't had time to get on the mill at all.

Have to admit - the struggles with the orient have really discouraged me as well. This has been a long journey and I naively thought I was close to finishing :laugh:

Right now I'm mostly thinking about how I am going to move this damn thing. I don't have a budget for a real rigger so right now I'm thinking about hiring a tow truck to winch the machine up while rolling on pipes. And at my new place, using my truck to winch it into the garage the same way.