Torch isn’t firing

I had time to take a look at your config tonight.  I see the following:

1. You are on version PlasmaC v.177 which was released in Sept of 2020.  The latest version is v.190 from Dec 2021.  I recommend you update, if you are going to use PlasmaC, you might as well use the latest version since there were some bugs that got squished in that time period.


2. You have the encoder hooked up in the _connections file for the voltage, but you are missing a few lines.  Add these at the end of the nfstring_connections.hal file:

3. On the config tab, you will need to calculate the voltage scale and voltage offset. The process is described in the PlasmaC user guide, but you can also use this calculator (also linked in the user guide): jscalc.io/calc/NTr5QDX6WgMThBVb

4. Make sure that the jumpers on your THCAD-10 are on Unipolar and F/32.


I think that should get your voltage going. The referenced section from the manual is here (link for your convenience): linuxcnc.org/docs/html/plasma/plasmac-us...uide.html#mesa-thcad

Aldenflorio wrote:

Also, how would I update my plasmac to the new version?

If you have a package installation of LinuxCNC then you need to change the repositories to point to the Buildbot by following the instructions for 2.8 branch at:
buildbot.linuxcnc.org/

Aldenflorio wrote:

Is there anything else I have to do? I know we said how since it’s a hypertherm45 (not xp) is a 50:1 ratio. What all is there to do that will ensure this THCad-10 wiring will work? Thank you very much

1. Make the changes to add the three lines to your file as I mentioned in the other post.
2. You need the frequency values off of the calibration sticker on the back of your THCAD. There is one for 0V and one for 10V
3. Go to the online calculator --> jscalc.io/calc/NTr5QDX6WgMThBVb
3a. Enter the 10V frequency in the top line
3b. Enter the 0V frequency in the next line down
3c. Frequency divider should be F/32, you should verify this jumper setting on your THCAD, though it is the default.
3d. THCAD model is -10
3e. Plasma Machine Voltage Divider Ratio is 50
4. You will get two number from the above calculator. Scale and Offset, write them down exactly.
5. On the Config Tab, in the "Arc" section, there are two entries marked Voltage Scale and Voltage Offset. Enter the values you wrote down in step 4 into these boxes.
6. Click Save.

Assuming everything else was wired correctly, etc. your torch voltage should work. You can verify the Scale and Offset by hooking a known DC power source (A 9V battery for example) to the THCAD input (if you decide this is necessary, you should probably disconnect the voltage out from the hypertherm first before you do this) and verifying that the screen reads 9V.