Drilling operation with Plasma post processor

My GoFabCNC machine doesn’t do small circles well and I’d simply like to pierce the center of those small holes and come back later with a handheld drill. However, despite having code for this in a few different post processors (pp’s), none work correctly.

I had started with the “GoFabCNC plasma”, which has the function OnDrill(), but when I add a drill operation to the g-code file, my GoFabCNC app crashes. Then I went to “Gofab plasma”, which also has OnDrill(), but the when the g-code file is loaded into the GoFabCNC app, an extra ‘path’ is added that seems start from the overall shape lead out, then left to the adjacent corner and diagonally to the middle. I got this same artifact with “Generic plasma with optional scriber”.

While I haven’t verified, I have seen something similar when testing other pp’s and those ‘phantom’ lines are real cutlines, so I can’t just ignore them.

How do I fix this??? Thanks



HMTA_CNC Part B-gofab.txt (1.5 KB)

Try this version of your file. Does it also crash Gofab?
HMTA_CNC Part B-gofab.txt (1.47 KB)

Yep, crashes.

I can’t see anything obviously wrong. I sent a copy of the code to GoFab to see if they can figure out what is causing the issue.

Thanks, Les! Not sure they’ll be much help, as I’m active in the FB group… Attached are 2 g-code files for the same part with the same post processor, but with cut circle (same as previous) vs pierce only. Anything illuminating???
HMTA_CNC Part B-gofab.txt (1.5 KB)
HMTA_CNC Part B-gofab_CIRCLE.txt (2.9 KB)

Plot thickens…

In trying various scenarios, including pp’s and dxfs, I found that the artifacts aren’t even due to the drill points, as even with a clean dxf of a 10.25" square, I’m getting the same artifact lines using the “Generic plasma with optional scriber” and “Gofab plasma” pp’s! I’ve attached both dxfs - with and without (-clean) drill points) - and the g-code from “Generic plasma with optional scriber”.

Nevertheless, the drill function works in “Generic plasma with optional scriber” and the square shape, etc work with “GoFabCNC plasma” - SO WHAT I REALLY NEED, is for the drill to work in the post I’ve been using all along, “GoFabCNC plasma”. Can you help with that?
HMTA_CNC Part B.dxf (140 KB)
HMTA_CNC Part B-clean.txt (845 Bytes)
HMTA_CNC Part B-clean.dxf (136 KB)