Halscope tuning servos Question

or if necessary even higher to 5m / div

alan_3301

I reran the scope and paid attention to having the trigger set to channel 3 and then to select channel 4 joint.0.f-error so its the active one. Once I ran the machine again and a new plot returned I found I could move the gain slider up and down and see the curve generated from different angles.

Here's the better one.



I also learned to save a file for each axis so I didn't have to keep reloading the channels.

Thanks for the help
Jim

Looks like you need (adjust in this order)

1. Higher FF1 ( adjust for 0 error during constant speed motion )
(if the following error is in the direction of velocity you need more FF1,
if the following error is in the opposite direction of velocity, you need less FF1 )

2. Higher P term ( adjust till its unstable then back off maybe 30% )

Easiest way to adjust things live is via the calibrate menu

PCW

Well I've been playing with the halscope and I am feeling better about what I am seeing.
My Machine

a 1985 Alliant knee mill (bridgeport clone),
SEM servo motors w/tacho, westamp boards, anilam A-10
glass scales. Mesa 5i25-7i77
GA-J1900n mobo, Wheezy, realtime-3.4-9-rtai-686-pae,
Linuxcnc from github master.
Axis 2.8.0-pre1.4032-g7626740

Because of the old anilam glass scales the axis have a "dither" of about .0004 which the current setting seems to help and since this is a hobby machine I am not nearly as picky as a production machine.

Here's some current scopes:
this is at 20 ipm (short jog)


this is at 7 ipm (short jog)


this is the calibration screen



Thanks
Jim

Looks better, still needs more FF1 (adjust to zero error during constant motion)

PCW

Hey I finally got it where it looks better. It didn't take much on X just from 4.0 to 4.15 and very close to that on the other axis.

Be sides PCW much appreciated help I found these pages very helpful

TommyLight's
HERE

BigJohn's page
HERE

The Hal Turorial
HERE

AndyPugh's (second posting down)
HERE

An old but interesting post
HERE

Much thanks to all of you.
Jim