Esab Ultrarex UXD-P2000 Upgrade Project

Ok got that. Good luck with those custom builds and thanks again for the precious help

Hi guys ! Long time no see !
Back to this project after a long pause, a new mesa 7i77 board and some wiring mess cleaning. We managed to do some successful test cuts. The machine did even cut some 12mm sheets last Friday. But we still have issues with height control as the torch gets too close to the materiel and this messes up the cut and the torch tip. I'm uploading some test cut videos and will upload some more in order to have your feedback on height control and correct voltage values. Big Thanks for Tommy for his great help with this project. @Tommy, hope you're doing well and enjoying your projects !
Will update with youtube links soon.

Video links:

Excellent to see stuff moving!
The torch voltage seems low but that is just a calibration issue.

Is there a reason why you are not using the qtplasmac config? 
linuxcnc.org/docs/stable/html/plasma/qtplasmac.html
Or did this project start so long ago it didn't exist?

The project started  before qtplasmac came out and I kept the plasmac config I did with Tommy a while back. I would like to get the machine working nicely as is before any software upgrades. If moving to qtplasmac will help with optimizing stuff I can give it a try. Next step is tuning the height control (Z) movement. Right now the Z is moving up and down only when sensing the metal sheet and then when the cut is finished. And if the metal sheet is slightly curved the Z does not account for that and we end up with a welded torch tip !

-disable auto volts
-disable void sense
-set VAD to 50%
-set cut speed to 1500
-set pierce height to 3
-set cut height to 2.5
-set pierce delay to 0.2
-set cut voltage to 90
Adjust cut voltage till the torch is about 1-1.5mm above material while cutting, use a welding mask to check.
Adjust the cut speed depending on the material being cut and the current set on the plasma source.
Do a lot of test cuts for every material thickness, look under it for dross, less dross = less cleaning.

Install Inkscape Unzip the attachment, copy both gcodetools_xxxxxx to
/usr/share/inkscape/extensions
yes to overwrite
Open Inkscape, draw something, Path menu, object to path, extensions menu>gcodetools>tools library>choose PlasmaC> apply
Again extensions menu>gcodetools>path to gcode , preferences tab>directory> add Documents , do not delete existing > path to gcode tab >clcik on "sort paths to reduce....."> click apply > click OK > close
Open in LinuxCNC, run.
-
Attachment is for older Inkscape, does not work on new versions, if anyone needs the new versions, let me know.

Hi Tommy. Thanks for the instructions. Will let you know how it goes.

Esaber wrote:

Right now the Z is moving up and down only when sensing the metal sheet and then when the cut is finished. And if the metal sheet is slightly curved the Z does not account for that and we end up with a welded torch tip !

It should see that and move the torch up. This is a sign you are not reading the torch voltage.

Assuming you are using a thcad, look at the encoder velocity in halshow while not cutting. Is it bouncing around near the 0 volt frequency. (/32) 

I guess if the amperage is too high for thin sheet metal, you may not see enough variation in voltage... Tommy will know more than m.

I think in one of his videos, the Velocity Anti Dive is always active and THC is never active despite being enabled, hence my procedure.
BTW, that procedure should be in the docs, preferably a bit better explained and formatted, and should be mandatory for properly setting up the machine initially. This would save a lot of headache later in daily use, although definitely the Phils Auto Volt thingy does a pretty damn good job given the variety of hardware used and the amount of things that can be wrong and still cutting decently.
And so should be the Cutting fine tuning, again not very important but can be the difference between 3 minutes of cleaning and 30 minutes of cleaning parts. I am sure i wrote about it, but can not find it, and again, this would also need a bit of fines as i am still not good at explaining stuff.