Centroid Community CNC Support Forum

Posted: **Fri Jun 27, 2025 3:36 pm**

Hey guys,

i have a problem setting up the scales on my machine viewtopic.php?t=11657

I had to invert Axis 1 (Z), so i entered -1000steps/mm instead of 1000.
Slowly jogging with the WMPG handwheel works, also for long distances, but when using the jog+/jog- buttons (VCP, WMPG, Keyboard, no matter where) the axis faults after maybe 50-100mm travel with "position error"

I chatted with Uwe, and he told me to enter 0,5-0,8 to the value "max-Diff" in the scales setup (most right value).
So i entered 0,5 there, hit enter, then save, exited scales-menu and double-checked, if the value has been saved. It has been saved, value is 0,5.

I exited CNC12, restarted CNC12, but still the same problem, axis goes to fault when jogging by keyboard/going fast. So i wanted to lift up the max-diff-value to 0,8. I entered setup, machine, scales, and the entry there is now 0,1 again?!?

I re-checked that behaviour multiple times.
Set diff-max to 0,5, saved, exited CNC12, restarted CNC12, and the value is back to default 0,1?

Report attached.
The scales themselves do work, when i push/pull on the slides, the last digit is changing slightly and the motor corrects that.

What am i doing wrong?

Thank you,

Marc

Posted: **Fri Jun 27, 2025 5:28 pm**

You are using 5.28

Get the latest 5.30

https://www.centroidcnc.com/centroid_di ... loads.html

Do a fresh install, not restoring report....

The settings are stored here:

Code: Select all

P571 =     0.50000  - Axis 1 Maximum Scale Difference (in, mm, or deg)
 P572 =     0.20000  - Axis 2 Maximum Scale Difference (in, mm, or deg)
 P573 =     0.10000  - Axis 3 Maximum Scale Difference (in, mm, or deg)
 P574 =     0.10000  - Axis 4 Maximum Scale Difference (in, mm, or deg)
 P575 =     0.10000  - Axis 5 Maximum Scale Difference (in, mm, or deg)
 P576 =     0.10000  - Axis 6 Maximum Scale Difference (in, mm, or deg)
 P577 =     0.10000  - Axis 7 Maximum Scale Difference (in, mm, or deg)
 P578 =     0.10000  - Axis 8 Maximum Scale Difference (in, mm, or deg)

Uwe

Posted: **Sun Jun 29, 2025 10:24 am**

I just updated to 5.3 and yes, THIS version seems to save that values correctly

But at first, on 0,5mm max diff, my axes were swinging extremely after every move! We are talking about approx. 1/10 turn back and forth! (2mm pitch)
So i set it to 0,1mm again to start finding a sweet-spot from there on, but with 5.3, now i can also jog faster on 0,1mm max diff without faulting, and there is also no swinging anymore.

But as this the first time for me installing servos, i will have to learn to fine-tune the axes first, too. I just made that one-click-tuning now. Which, btw, seems to give good results, no see- or audible swing, no strange sounds, no vibration. But it can't be THAT easy, right?

Even if it's Leadshine...^^

If anyone knows some documentation, video, or any other resource, where tuning of a servo-motor on a cnc-machine is shown, i'd be happy about some links or info on it

I mean the basics regarding tuning here, e.g. what values to monitor in the scope, what deviation-results to achieve and so on.

Best regards,

Marc

Posted: **Sun Jun 29, 2025 11:29 am**

First step is to tune your servos as stiff and fast as possible.

Second step is to tune the scale feedback loop in CNC12 for minimum oscillation

I prefer to use P#620-635 to tune the scale feedback...

Code: Select all

P620 =     0.01200  - Axis 1 Scale Proportional Constant
 P621 =     0.01200  - Axis 2 Scale Proportional Constant
 P622 =     0.00500  - Axis 3 Scale Proportional Constant
 P623 =     0.02000  - Axis 4 Scale Proportional Constant
 P624 =     0.02000  - Axis 5 Scale Proportional Constant
 P625 =     0.00000  - Axis 6 Scale Proportional Constant
 P626 =     0.00000  - Axis 7 Scale Proportional Constant
 P627 =     0.00000  - Axis 8 Scale Proportional Constant
 P628 =     2.00000  - Axis 1 Scale Max Correction Velocity (encoder counts / interrupt)
 P629 =     2.00000  - Axis 2 Scale Max Correction Velocity (encoder counts / interrupt)
 P630 =     2.00000  - Axis 3 Scale Max Correction Velocity (encoder counts / interrupt)
 P631 =     2.00000  - Axis 4 Scale Max Correction Velocity (encoder counts / interrupt)
 P632 =     2.00000  - Axis 5 Scale Max Correction Velocity (encoder counts / interrupt)
 P633 =     0.00000  - Axis 6 Scale Max Correction Velocity (encoder counts / interrupt)
 P634 =     0.00000  - Axis 7 Scale Max Correction Velocity (encoder counts / interrupt)
 P635 =     0.00000  - Axis 8 Scale Max Correction Velocity (encoder counts / interrupt)

Uwe

Centroid Community CNC Support Forum

Scale Setup not saving values?

Scale Setup not saving values?

Re: Scale Setup not saving values?

Re: Scale Setup not saving values?

Re: Scale Setup not saving values?