Grbl gcode for cnc plasma

[jeremy_smitty]

I’m a newbie with cnc, so take that into account when it comes to this post.

I’ve been itching to get a cnc plasma table for a while now. To get the ball rolling on this, I am starting with something very small - I am converting a cnc laser engraver, which uses laser grbl, into a cnc plasma cutter.

After playing around with this setup for a year, I will invest into building a 4x4 table. I have been teaching myself freecad, in the 2d sketcher area, and I am slowly getting better.

I am having some challenges generating gcode for the lasergrbl right now. I dod some reading, and a few people have mentioned that cnc plasma tables run off lf mach3, not grbl.

Do i need to change the laser cnc controller, to a mach3 controller board, to get this to work? Or, can gcode be generated to work on lasergrbl, and still control a plasma setup?

Is there a particular software out there that will generate gcode from the dxf files i create on freecad, which is then compatible with running a plasma on grbl?

[djreiswig]

Look into SheetCam. I believe it has a post processor for grbl. Not sure what is special about the laser code, but I'm sure it could be produced in SheetCam.

[acourtjester]

I think if you Google MPCNC you may find some who have used GRBL for plasma cutting.
https://forum.v1e.com/t/my-attempt-at-a ... tter/25461

[bLouChipBlacksmith]

You can use a grbl controller to run a plasma CNC table. As with any controller, you need to take precautions to mitigate EMI, but grbl controllers tend to need extra precautions because many are made from bare bones MCU boards such as Arduinos and the like. Typically these boards don't have opto-isolated I/O, no metal enclosure shielding, and the CNCs are usually wired without shielded cables. You likely have one like that if you have a hobbyist laser CNC. I have an Arduino grbl controller and it was challenging to say the least to mitigate EMI when I implemented plasma process; I started from laser and routing processes with my CNC. A plasma cutter, and specifically the plasma arc, is essentially a high power EMI transmitting station.
I have posted some EMI mitigation s tips here: https://millrightcnc.proboards.com/post/24709/thread

re. LaserGRBL the freeware program if that is what you are referring to- it is CAM and gcode sender in one Windows program, specifically for laser CNC; its not grbl, it "talks" to grbl, which is the gcode interpreter on the MCU board constituting the CNC controller. If you like using LaserGRBL as the control program for your CNC (jog, home, WCS zeroing, etc), then you may be able to generate plasma specific gcode (actually very similar to laser), save it in a file, and have LaserGRBL load that file for sending to your CNC much as it does now, I don't know if it would filter out gcodes it doesn't expect, hopefully not. As @djreiswig suggested, SheetCAM can generate the plasma toolpath (gcode) for grbl controllers. I use it to do that. SheetCAM takes dxf or svg as input; it does a great job generating the toolpath with enormous customization capability.
I use this post processor: https://forum.sheetcam.com/viewtopic.ph ... 0&start=15
And an alternative to LaserGRBL as a gcode sender program is UGS, I use it and like it since it allows for unlimited gcode macros and has a good simulator/tracker graphical window and nice large DRO XYZA coordinate readouts. http://winder.github.io/ugs_website/

If I were building another CNC table for multi-process such as plasma, laser, and routing, I'd likely use grblHAL as the controller. It supports up to 5 axes, and there are EMI hardened MCU boards available for it, as well as a grbl controlled THC addon.
https://github.com/grblHAL and here: https://github.com/phil-barrett/grblHAL-teensy-4.x
Another good choice for a multi-process controller is LinuxCNC.

[weldguy]

You can use a grbl controller to run a plasma CNC table. As with any controller, you need to take precautions to mitigate EMI, but grbl controllers tend to need extra precautions because many are made from bare bones MCU boards such as Arduinos and the like. Typically these boards don't have opto-isolated I/O, no metal enclosure shielding, and the CNCs are usually wired without shielded cables. You likely have one like that if you have a hobbyist laser CNC. I have an Arduino grbl controller and it was challenging to say the least to mitigate EMI when I implemented plasma process; I started from laser and routing processes with my CNC. A plasma cutter, and specifically the plasma arc, is essentially a high power EMI transmitting station.
I have posted some EMI mitigation s tips here: https://millrightcnc.proboards.com/post/24709/thread

re. LaserGRBL the freeware program if that is what you are referring to- it is CAM and gcode sender in one Windows program, specifically for laser CNC; its not grbl, it "talks" to grbl, which is the gcode interpreter on the MCU board constituting the CNC controller. If you like using LaserGRBL as the control program for your CNC (jog, home, WCS zeroing, etc), then you may be able to generate plasma specific gcode (actually very similar to laser), save it in a file, and have LaserGRBL load that file for sending to your CNC much as it does now, I don't know if it would filter out gcodes it doesn't expect, hopefully not. As @djreiswig suggested, SheetCAM can generate the plasma toolpath (gcode) for grbl controllers. I use it to do that. SheetCAM takes dxf or svg as input; it does a great job generating the toolpath with enormous customization capability.
I use this post processor: https://forum.sheetcam.com/viewtopic.ph ... 0&start=15
And an alternative to LaserGRBL as a gcode sender program is UGS, I use it and like it since it allows for unlimited gcode macros and has a good simulator/tracker graphical window and nice large DRO XYZA coordinate readouts. http://winder.github.io/ugs_website/

If I were building another CNC table for multi-process such as plasma, laser, and routing, I'd likely use grblHAL as the controller. It supports up to 5 axes, and there are EMI hardened MCU boards available for it, as well as a grbl controlled THC addon.
https://github.com/grblHAL and here: https://github.com/phil-barrett/grblHAL-teensy-4.x
Another good choice for a multi-process controller is LinuxCNC.

Great topic, great info, thanks guys.