Replacing Advanced Motion Controls "brush type 12A8 with "Axcent" amplifier

Todd, many thanks! This pic shows the current set up using only the channel 1 (N.joint-vel-cmd)& channel 4(hm2-5i25.0.encoder.00.velocity); all others are off, this is the "x" axis only. I need to make these trace look as close as possible to each other, this at approx 40'/min, as in pic. When I start y axis, will have values in the low P (just like this), with low feed rate, work up to 40"/min.
many thanks!



From tommylight post: Example:
say the 0.5 value had a slower rise or fall of the f-error line on the scope, put 0.4 and test again. If the move of the f-error line was slower, lower it a bit more say 0.3 and test again, it it was faster, increase it a bit to 0.45 and test again.
End of example

Am I to look at the height of the line or the amount it goes above the reference line?

Still too much P, You're trying to get rid of those oscillations. What does it look like with P=2000?

This is most recent, 46.7"/min. some how the original text from this post may not appear.

many thanks!

Ok, now with P set to 2000, increase the FF1 until the average velocity feedback matches the commanded velocity during the cruse part of the move.

You need to dial in the feed forwards better before cranking up the P. When the P is set very high it makes it very hard to see what the feed forward terms are doing as you tune them.

The cyclic error during cruse is a little disappointing. Can you describe the mechanics of the axis? Also the drive may need better tuning. Is the drive receiving any form of feedback from the motor for calculating velocity (tach, encoder)?

Todd, Thank you. The pic shows the setting as per prior post, need to verify is this ok. The feed is low (10"/min), if I set it higher will have joint error. This axis is the "x" axis of Bridgeport Mill. The motors have encoders (2000 count seems correct) built in. Will it help to add the other channels?

Many thanks!

Edit: When testing axis in question I only compare (or take pic) if the direction is the same (facing machine "x axis" moves to the left) as the other tests.

Yes, showing the f-error and the PID output could be helpful.

Is the servo drive receiving any form of feedback from the motor?