I created a configuration for one of our twin spindle routers (Z and W axis). 
In order to take advantage of the new trajectory planner, I could not use W 
movements in the carving G-code (only XYZ work). As a workaround I made a 
config that can use a couple of M1xx codes to slave and unslave the movement of 
the W axis to the Z. It seemed work quite well in a sim stepper config, but I 
am having some trouble with it on the real machine with servos. 

To slave the W to the Z I will command both axis to the same height (relative 
to the material) usually with a g0z1w1, followed by the slaving M-code m122. 
This uses a couple of Mux2 components to connect the z-position command + an 
offset to the w-PID and the w-PID error + w-position command are connected to 
the w-feedback. So (when it's working) while the W is moving with the Z, the 
DRO shows W=1(+/- servo error). 

The problems I am having are: 
After first starting Linuxcnc, the first time I call the axis slaving command 
(M122) I almost always get a joint 8 following error, the Linuxcnc goes into 
shutdown (F2), and even while in shutdown or e-stop the DRO for the W will 
continue to runaway, but the axis will show no movement. If I Press F2 and 
issue an MDI G0W1, it will usually return the W back to what it should be, and 
I can unslave the axis and return to normal behavior. 

After this initial screw-up it will often behave fine for the rest of the day, 
slaving and unslaving at the start and end of each run. 

But once in a while for some reason it randomly does the DRO w runaway (w-axis 
hasn't actual ever moved noticeably). Issuing an MDI w command usually rights 
it. 

This afternoon it took off once when no one was watching and when I got to it, 
F1 and F2 (e-stop and machine power) were completely unresponsive, while W DRO 
showed over 43K inches and climbing. Since I could not re-power the control, I 
could not issue the MDI w command. I had to close Axis and restart. 

Any suggestions 

I also posted this question to the Forum, and a copy of the servo config is 
posted there. 
http://linuxcnc.org/index.php/english/forum/10-advanced-configuration/29807-trouble-debugging-config#64158
 

http://linuxcnc.org/media/kunena/attachments/3190/Dig4zz_2015-10-22.zip 

-- 

======================================== 

Todd Zuercher 
mailto:[email protected] 

======================================== 
------------------------------------------------------------------------------
_______________________________________________
Emc-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/emc-users

Reply via email to