I am using a Hypetherm 45 XP using the THC.
Here is the code for the first two holes. The first always fires. After that not. In Sheetcam I tried to create the code with two holes being on separate layers and separate operations but it made no difference. Still only the first mark fired.
M3
G4 P0.5 <== this may be too long for a 'peck' type operation, I use about 150mS (G4 0.150)
G1 Z0.059 F230.0 (Cut Height)
H1 <== this turns ON THC - you don't want to use THC for a peck operation
G1 F230.0 <== this doesn't DO anything (there is no movement) so FireControl might not turn on the torch
H0
M5
I will say that I have not used this method with FireControl so maybe others can help you with this…
The peck is longer than I would like but didn’t want to get in start changing things in the code as this is the first time I am looking at the code. Things have just been working so haven’t had a need. I turned down the amps on the plasma cutter and can work with that mark for the size hole I am going to be making.
Turn off in fire control screen, and you can add pause to sheet Cam after last hole is center punched to turn back on THC then hit start to finish cutting program.
When THC is turned off do I need to set a Z height or is there something in the contact with the plasma tip and workpiece that tells fire control when to fire off the torch?
IHS (Initial Height Sensing) will establish Pierce and Cut Heights entered in your tool setup (SheetCam). (In Fusion, the values are entered in the Post Processing window.) THC (Torch Height Control) will attempt to maintain the cut height during the cut. With THC turned off, IHS still controls the Z axis heights.
If you want to pierce the center of holes, here is a post processor made by @manoweb. I have heard that is works great. It is not designed to cut your entire project, just piercing the centers of holes.
Here is his post: (Edited based on Tom’s thoughtful guidance )
Perhaps you could decrease the amperage to get just a mark versus an actual pierce, if that is your goal.
Be aware that you should use the version posted in the follow on post at:
For two reasons: The first being that it’s been improved, but more importantly, the original version used a very bad naming convention that is bound to be trampled on by Langmuir if they ever release an updated post processor.
Just tried turning off the THC. 3 holes to mark. First hole great. Second hole, about 3 inches away, nothing, 3rd hole, one inch from 2nd, fired. Thought it was a time thing so put in a delay after the mark and no change other than the delay.
Went back to sheet cam and made a file for the missed hole.
With THC off I run the first file with the three marks with the second mark not firing. Then run the missed mark, Turn up amps from 20 to 45 and cut the profile for that piece.
On the third time through this I forgot to turn off the THC and the behavior was the same. First hole marked, second hole, not firing, third hole fired.
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