Gmoccapy v3 handling of angular_velocity

Hi everyone,

I tried my hand at getting a fourth axis (A) going today. While I did get it to show up in gmoccapy as A together with an additional slider for the velocity for manual jogging, I did encounter an issue.

in my machine.ini I placed the following with DISPLAY and TRAJ
Regardless of the values for DEFAULT_ANGULAR_VELOCITY (tried 36, 180, 360, ...) gmoccapy starts with a velocity of 360°/min and goes up to 10 times that (3600°/min). I had expected the value in the gui to change according to the ini file.

linuxcnc.org/docs/devel/html/gui/gmoccapy.html doe snot mention "angular" at all. I guess I am chasing the wrong variable. What can I do to fix it?

I am using a recent 2.9 install.

Cheers and thx

Guido

For whatever reason GMoccapy doesn't read the INI for angular defaults.
It uses a special GladeVCP widget that has bben set at default 36 max 36000

To change it would require loading GMoccapy's Glade file in the Glade editor (GTK2 version) changing the defaults and saving it.

Chris

Thank you Chris,

I figured that much. Has this been raised as a bug on github? If not; I'll be happy to do so.

Cheers

Guido

I have not. Feel free.

I have raised the issue within github. I will have a look at it myself. Doesn't seem to be too bad to do. But i am utterly unfamiliar with the process of working on large scale community driven software projects. I guess the correct way is to fork linuxcnc and play with it there?

Furthermore, I have discovered something else which is a bit odd.

If I jog A axis in gmoccapy at speeds above~800°/min the motor is stuttering. If i send it around with G1 or G0 at speeds up to 10800°/min it is running perfectly smooth. Any ideas?

Fork is the usual way - you can add a pull request. A small patch file would work too.

Is your a axis a stepper? could it be resonance?

Thanks for getting back to me on both topics!

I have since made a fork () and started playing around. Will take some more time for testing, but I think the major issue has been taken care off. I will report back.


On the axis issue:
Yes, my a axis is a stepper. Somehow I never encountered resonace in such a bad form with steppers in the past. I thus had not thought about. Accordingly the error is of course not within the interface - sorry about that. I had tried similar but not identical speeds. With resonance this of course can lead to disaster.

I have a Nema34 with 8 wires connected to a Leadshine DM856. It runs at 4000 Steps/rev and at 3.8A. I initially had it connected in serial configuration. I have since switched to parallel connection as per the picture in the link below.
See: www.longs-motor.com/de/hybrid-stepper-motor-nema34.html

It now works fine. There is a spot where it starts to whine a bit, but within the usable range it did not have any hiccups or severe stuttering. Torque is not really an isseu for me, as the forth axis gous from the stepper through i=40 planetary gearbox that I had laying around.

Thanks a lot Chris and Happy Easter.

Hi Chris
Are you aware that you can "optimize" this stepper driver via serial and leadshine sw?
Mike

Hello! I have this same problem, It's been driving me crazy for several days. I'm not sure I understand how to edit the glade file. can someone point me to a tutorial? <

---

I figured it out, for anyone else gmoccapy's glade file is located in /usr/share/gmoccapy/ the GLADE editor for me was found under Applications->Development->glade It took me a minute to realize i had to maximize the window to find the angular slider. Click on it and change the settings then save as somewhere. then in the terminal do a sudo cp back to it's original location.

Thanks, first bit of progress in days.

My g0 and g1 commands are still throttled at 60/deg per minute

g0b360,
g0b360f4000 both limited to 60/deg per minute. Any advice?

I fixed that yesterday, I missed to check the INI file for angular velocities. I pushed only to 2.8 release.

Norbert