Jet cutting tool path pierces twice when using kerf comp

[Anonymous]

I'm using the jet cutting 2D Profile to post some simple contours to my plasma machine using a slightly modified version of the example jet port. The issue I'm having is that when compensation type "In Control" (G41, G42) is used, the toolpath generated ends up with two torch enables and disables at the start of every profile.

This can be seen in the toolpath preview as well:

This only seems to happen when using G41/G42 compensation. In the generated code below, you can see the first small move seems to be a special lead in for the switch from G40 to G41:

(1001)
(THICKNESS = 1)
N10 G90
N15 G21

(2D Profile2 2)
(Plasma cutting)

(tool.jetDiameter = 5)
(tool.jetDistance = 3)

(THROUGH CUTTING)
(QUALITY = 0)

N20 G0 X201.66 Y42.248
(TURN ON CUTTING HERE)
N25 M7
(RUN POINT-PIERCE COMMAND HERE)
N30 G41
N35 G1 X200.41 Y44.414 F3900
(TURN OFF CUTTING HERE)
N40 M8
(TURN ON CUTTING HERE)
N45 M7
(RUN POINT-PIERCE COMMAND HERE)
N50 G41
N55 X191.75 Y39.414
N60 X190.667 Y38.789
N65 X190.5 Y38.498
N70 Y0
N75 X0
N80 Y43.18
N85 X190.5
N90 Y37.248
N95 Y35.998
N100 X190.667 Y35.708
N105 X200.41 Y30.083
N110 G40
N115 X200.41 Y30.083
N120 X201.66 Y32.248
(TURN OFF CUTTING HERE)
N125 M8

N130 M30

Does anyone know how to disable that first tiny move and torch activation? It's making my cutting routines look really silly and take a long time because the table does a full ohmic touchoff for each call to M7.

[paul.clauss · Accepted solution]

Hi @Anonymous

Thanks for posting. The only time I've seen piercing like this is when the Top Height of the cutting operation is above the stock top. Does changing the top height for the operation to the stock top (you could always add height to the stock to adjust) resolve this issue?

I hope this helps! If you continue to see problems, please share the problem design with me - I'm happy to have a look.

[Anonymous]

Hi @paul.clauss, my Top Height was set to Stock top with 0 offset, which results in an initial toolpath like I showed above.

 

It seems like changing the Top Height to "selected contour" is actually what fixed it. Anything else causes the double pierce.

 

 Thanks for pointing me in the right direction! I just wish I understood why it needs to happen that way.

[paul.clauss]

Hi @Anonymous

Thanks for the response! I'm unsure of why the heights are having this effect on the toolpath and am thinking you may have found a bug - I've reached out to the CAM development team for confirmation on this. We appreciate you bringing this to our attention!