Sheet cam GRBL torch probe post processor

Problems and questions
21

The post is working great and doing exactly what i want it to do. Thermal Dynamics machines need a 2 delay for the first pierce, I played and tried to get it to work but no luck. Possible to set this post up to work with that
GRBL plasma LDC v24-12-8 (2).scpost (9.81 KB)

22

@devloop-
I added an internal var in OnInit(), LdcFirstPiercePD = 2.0 – seconds.
It seems to work as I understood you wanted, first pierce is total of 2.0 seconds. I noticed you left (from original version) the code to include the plunge time from PH to CH as a component of pd, so that is effective in the first pierce also.
GRBL plasma LDC v24-12-8 w firstPiercePD.scpost (10 KB)

23

Appreciate the help, Ive added your lines to my post and still wont delay on the first pierce, what im i missing
2024 Post Delay.scpost (9.65 KB)

24

no worries, you missed a few lines.
I added another condition in this version, to isolate the first pierce logic.
Also, there were some other changes also in the latest scpost you provided, you had changed M7 to M8, and you’re using 5.5mm for LdcTorchProbeTravel. These are as they were in this corrected scpost.
2024 Post Delay w firstPiercePD.scpost (9.66 KB)

25

Is it possible to take my post and add the touch off to it with the probe, one simple touch off.
Devko Plasma Table Post Rev1 (1).scpost (3.15 KB)

26

Try the attached, it produces the following gcode, PH being 3.2mm in the tool, XY being the pierce location.
See the function DoTorchProbeCycle() to make adjustments.

G0 Z3.2
G38.2 Z-13.0 F1000.0
G92 Z-10.0
G0 Z3.2X113.277Y150.123

Devko Plasma Table Post Rev1 w TorchProbeCycle.scpost (4.14 KB)

27

Its running spot on, except it raises the torch exactly .25" too high during the cut. What could it be?

28

You have to adjust the floating torch distance which actuates the probe switch. I arbitrarily set it at 10mm.
Given you report that the torch is cutting 0.25" too hight, your value is going to be 10 - 6.34 = 3.66mm
Edit the .scpost and replace this function with this corrected code. I also made a mistake in the original by moving Z to pierce height before the probe, it should be Z0, which this version also corrects.

function DoTorchProbeCycle()
   local floatDist = 3.66    -- mm, the distance to activate the probe sensor
   local probeFeed = 1000     -- mm/min
   
   -- start from Z0
   post.Text("G0 Z0 \n")
   -- probe until sensor actuated
   post.Text("G38.2 Z-", post.FormatNumber( (floatDist + 3) * scale, format), " ")
      post.NonModalNumber("F", probeFeed * scale, "0.0###")
      post.Eol()
   -- set temporary Z0 to top of material, relative from current position
   post.Text("G92 Z-", post.FormatNumber( floatDist * scale, format), "\n")
   -- move to pierce height
   post.Text("G0 ")
      post.NonModalNumber("Z", pierceHeight * scale, format)
      -- the following does not cause motion, but it restores XY location precision
      -- to satisfy arc motion (G2/G3) if used on leadin, else random error33 can occur
      post.NonModalNumber("X", currentX * scale, format)
      post.NonModalNumber("Y", currentY * scale, format)      
      post.Eol()
end
29

Working perfect, cant thank you enough!