Path for plasma cutter

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Kevinpradou
Posts: 3
Joined: Sat Sep 24, 2022 9:00 pm

Path for plasma cutter

Post by Kevinpradou »

Hi, my name is Kevin from France, i’m using path to create a G-code which command a cnc router for plasma cutting. The plasma cutting head is activated when the G-code try to spin the milling tool. My problem is the tool is spinning when traveling between milling locations with the g-code created, and on my machine is will start the plasma cutting head and cut the part when travelling. How can I configure Path to start the tool only where is has to cut and stop when traveling?
Thanks for your help
chrisb
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Re: Path for plasma cutter

Post by chrisb »

Hi and welcome to the forum!

This sounds as if you need a slightly modified postprocessor. Which one do you use?
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GeneFC
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Re: Path for plasma cutter

Post by GeneFC »

Several people have reported on using the Path WB to create code for lasers. I would guess that the solution for plasma might be related.

Try a search on "laser" in the Path/CAM forum.

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pathfinder
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Re: Path for plasma cutter

Post by pathfinder »

Kevinpradou wrote: Sat Sep 24, 2022 9:09 pm Hi, my name is Kevin from France, i’m using path to create a G-code which command a cnc router for plasma cutting. The plasma cutting head is activated when the G-code try to spin the milling tool. My problem is the tool is spinning when traveling between milling locations with the g-code created, and on my machine is will start the plasma cutting head and cut the part when travelling. How can I configure Path to start the tool only where is has to cut and stop when traveling?
Thanks for your help
The nice thing about gcode is that it's human readable and therefore you can edit it in a text editor.

This is a bit of a hack, but in an engraving operation, there's two things you can use to make the gcode suitable for your application after generating it.

By default, FreeCADs engraving operation will generate two gcodes that are relevant here:

1.: G0 Z5.000, which it does when it retracts, and
2.: G0 Z3.000, which it does right before it moves to cutting depth again.

What you can do with this information is generate gcode, then open it in a text editor and use batch search and replace to edit in your commands.

Search for

"G0 Z5.000"

and replace it with whatever the code for turning the Plasma off is. Note that you should be able to replace one line with multiple lines. So let's say you want to turn the plasma off and retract it 5mm upwards, you should be able to replace G0 Z5.000 with

"Go Z5.000
[Turn Plasma off command]"

Same with other commands you might need, like a wait command.

To turn it back on, do the same for

"G0 Z3.000"

but this time replace it the Turn Plasma on command.


You'll probably also have to edit the preamble and postamble to commands your machine expects, but this may be as easy as copying them from a working gcode file that you already have. To make sure, go check the gcodes and what they stand for, though.

If you plan on regularly using FreeCAD, you may want to look into how you can automate the process, but as a quick workaround, it should work okay.
Kevinpradou
Posts: 3
Joined: Sat Sep 24, 2022 9:00 pm

Re: Path for plasma cutter

Post by Kevinpradou »

Hi, sorry for the delay, i'm on french hours.
I'm using GRBL postprocessor but i don't know how to modify it.
I haven't find my answer on the other post right now but i will looking for again.
I know i can modify the G-code and i already try it, it works find, the machine cut my metal part very well. But i need to automate it as i will use Freecad a lot to create parts and G-code for this home-made plasma cutter.

Thanks again for your help
Bance
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Location: London

Re: Path for plasma cutter

Post by Bance »

Have a read of this page....

Path_Postprocessor_Customization
Kevinpradou
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Joined: Sat Sep 24, 2022 9:00 pm

Re: Path for plasma cutter

Post by Kevinpradou »

Ok, i understand my solution is there but i don't have the skills necessary to modify it. I'm just a beginner and i'm better to built stuff than to program them...

with the GRBL post processor it don't miss a lot to work with my plasma cutter and if you forgive it is a plasma (but a mill as GRBL wish to command it), the only thing i need is to suppress the command which spin the tool all the time, add a command to spin it when it goes down to the part it start to mill it and stop spinning when it goes up to the next spot to mill.

you think you can help me on this stuff?
Bance
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Re: Path for plasma cutter

Post by Bance »

chrisb
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Re: Path for plasma cutter

Post by chrisb »

And there is the folding attachment mode.
Sorry, wrong forum
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freedman
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Re: Path for plasma cutter

Post by freedman »

It's been years since I looked at gcode. I would think there is a command to turn the laser on and off, I would think there is a direct correlation.
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