Fighting the PID!

Andy and PCW Thank you both for the help with my spindle setup. 3000 rpm was the one that was right from the start with only FF0 =1.

With these settings the spindle speed is pretty good throughout the range. Higher speeds 2000+ are better than that the lower speeds but I trust it enough to make chips with it. Now my spindle-at-speed signal needs a little tweaking after reading some docs the other night I think I understand how to get that working correctly . After that it is on to stopping motion if the spindle faults and getting the E-Stop finished.

P = 0
I = .9
D = 0
FF0 = 1.0
FF1 = 0.0
FF2 = 0.00

Thank guys
John

Although I got the PID basically working the spindle speed wasn't as stable as I would like so I decided to give lincurve try. Now I am happy with the spindle. I thought I would post this here in the event that someone else goes down the same road that I did. Maybe this will help them find the info a little sooner. Below are the lincurve related hal entries.

lincurve documentation

loadrt lincurve personality=16
addf lincurve.0 servo-thread

#Enter the commanded (Desired) speed in the lincurve.0.x-val-NN entries
#Enter the command required to achieve the desired speed in lincurve.0.y-val-NN.
#Where NN is 00 - 15
#To start make the lincurve pair equal. Then test each speed and adjust lincurve.0.y-val as needed.
#Ii found that I had to make a couple of passes through this process to get everything where I wanted it

setp lincurve.0.x-val-00 1000
setp lincurve.0.y-val-00 1105

setp lincurve.0.x-val-01 1250
setp lincurve.0.y-val-01 1310

setp lincurve.0.x-val-02 1500
setp lincurve.0.y-val-02 1505

setp lincurve.0.x-val-03 1750
setp lincurve.0.y-val-03 1720
setp lincurve.0.x-val-04 2000
setp lincurve.0.y-val-04 1950
setp lincurve.0.x-val-05 2250
setp lincurve.0.y-val-05 2150:)
setp lincurve.0.x-val-06 2500
setp lincurve.0.y-val-06 2360
setp lincurve.0.x-val-07 2750
setp lincurve.0.y-val-07 2570
setp lincurve.0.x-val-08 3000
setp lincurve.0.y-val-08 2780
setp lincurve.0.x-val-09 3250
setp lincurve.0.y-val-09 3000
setp lincurve.0.x-val-10 3500
setp lincurve.0.y-val-10 3210
setp lincurve.0.x-val-11 3750
setp lincurve.0.y-val-11 3425
setp lincurve.0.x-val-12 4000
setp lincurve.0.y-val-12 3640
setp lincurve.0.x-val-13 4250
setp lincurve.0.y-val-13 3855
setp lincurve.0.x-val-14 4500
setp lincurve.0.y-val-14 4050
setp lincurve.0.x-val-15 5000
setp lincurve.0.y-val-15 4475

net spindle-vel-cmd-rpm-abs => lincurve.0.in
net spindle-output <= lincurve.0.out
net spindle-output => hm2_5i25.0.7i76.0.0.spinout

John