Schaublin 125-CNC retrofit.

Do some scope plots of f-error and post them here, i did tune two machines today, one with velocity drives, the other seem more like torque drives.

"graph servo analog out in hal scope,"
By that you mean joint.x.vel-cmd right?

Starting with X axis:
Drive automatic rigidity = 18 (Scale 0-31)

My starting point was a P of 15. with a bit of FF. This was what I have been using to machine with the Schaublin, which is not a perfect tuning, but the machine basically worked.

"turn the P setting to zero , set ff1 to 1 make sure the other ff settings are zero"
Done.
Tiny move and following error.

Set drive automatic rigidity = 1
Larger move, and following error.

Not sure how to get started from this point. As I cant start tuning , until I have stable motion again.

Thanks for the explanation why there is no Following error parameter in the drive Osci. In hindsight I probably should have used a Step/card rather than the 7i83.
 

take a picture of the v-out analog out voltage trace.

let's see what the output looks like. that will tell what needs to be changed in the drive settings.

think of it as follows.


vout is throttle
p is idle controller
ff1 is idle sprak/fuel adjustment


to put it into engine terms.


if your relationship between throttle request and engine rpm is wrong, all your doing is bandaids the problem with ff1 and p

first step is, what's the maximum velocity of the drive 0-10v

is that the same as you maximum velocity in linux cnc ??

this is throttle or gain in the drive. linuxcnc is the driver with the throttle, the drive is the engine.

there needs to be gross agreement between the commanded velocity and the actual velocity. now that you have following errors, you should be able to work on adjusting the relationship between the motion control command and the drive. 


post your drive manual, I'll read it through tonight 
 

I'll get to that tomorrow evening. Thanks a lot for your advice. I need it

RotarySMP wrote:

Starting with X axis:
Drive automatic rigidity = 18 (Scale 0-31)



"turn the P setting to zero , set ff1 to 1 make sure the other ff settings are zero"
Done.
Tiny move and following error.


 

First is probably what other manufacturers call "damping".
Second, that is open loop so LinuxCNC has no control over it except outputing whatever is requested from software on the analog output, and since the encoders are wired, after a 1mm move it cuts off with joint error.
-
-leave rigidity at 18
-have a run through this:
forum.linuxcnc.org/10-advanced-configura...ning-detailed-how-to

I didn't get to the basement this even due a long work day and then visitors. Tomorrow looks better as I will work from home.
This is the JMC Servo driver manual. Thanks a lot for your support on this.
www.jmc-motor.com/file/1806080392.pdf
Cheers,
Mark