On Freecad, G-code and post processors

Hello, happy community !

Crossfire pro is installed, but not ready for production yet, as some compressor power issues arose, preventing good cuts. It is a hobby side project of a friend I am helping with, and you bet we can’t wait beaming through the sheets ! :slight_smile:

Meanwhile, I am practicing on the workflow. The table is connected to a Windows laptop, on which were installed all of the suggested software, which seems to work fine, albeit I did not yet test adding G-code to a simple design made in Fusion 360, and just tried the cuts manually from Fire Control.

I need your lights on how specific is G-code made from F360 to feed Fire Control, and what exactly is a post processor doing…

In fact, since I am using linux myself, I installed FreeCad to design the parts of an assembly project to be cut, and there is a Workbench module to create and export G-code…

Does anyone know if or how this produced G-code could be used in Firecontrol ?
Is a post processor a kind of translator of G-code to specific Fire control script ?

Well, thanks for any hints :slight_smile:

Oh, and I was eventually given the incentive to write this after receiving an email stating that free version of F360 was now nerfed, something I saw quite a lot happening in the past, and I would really prefer using open-source software.

Given it’s FreeCad I would expect the workbench module to have a configurable post processor. Did you check in to that?

FireControl is pretty generic, but there are some specific changes for Z Calibration (IHC) and Torch Height Control. Nothing complicated, just different than what Mach 3 puts out, for example.

Thanks Tom for that speedy and insightful reply !

Indeed Freecad permits customizing postprocessors, and I did learn some more since initial post, thanks to their wiki !

But it is all confusing for a first contact, and I hoped to compensate my short sight in this digital forest by hopping on the giant shoulders of you pros…
And to see if there are other open-source oriented users to give it traction.

I am still researching to establish a good workflow, and not into details yet that would need me to open the hood of a pandora scripts, so pointers to understand how to import Gcode into Fire Control, or the way the postprocessors were written for F360 would be handy to not lose too much time on dead ends :stuck_out_tongue:

I guess I’ll now try to find docs on Fire Control GCode implementation…

Good luck with that. If you find any please post them…
The best ‘source’ is to look through code that others on this forum have posted to try to discern the differences.

Oh… Well ! I hoped to attract just that with this post, because could not get much info after searching forum for gcode and postprocessor, beside an interesting gcode tutorial.
G-coders, don’t be shy !

So I did inspect the postprocessors for F360 and Sheetcam, at first glance it seems to be clean coding

The one for F360 is copyrighted to autodesk, the one for Sheetcam, much smaller, is referencing Langmuir, so maybe (but little do I know) would not be too hard to adapt or change parameters if some guru is around when big compressor is installed and I can dig deeper on it.

When I signed up for hypertherms pro nest, all they needed was a sample of a working g code file that I had used, and they made a post processor for me to use with the crossfire pro and their software.

Like @TomWS said, everything you need to make your own post would be in those files. I’m almost to the point where I am going to dig into that aspect of the hobby. There are a few tweaks I want to do.

Dom I havent looked into this but I would assume FreeCAD’s 30k+ users might be able to help write a post processor to generate the correct Gcode for Fire Control. I am also interested in moving from limited unless you paid programs to open source.

Don’t know if it will help with FireControl, but I’ve modified the Mach3 postprocessor for FreeCad to work with the Crossfire. I’d be happy to share if anyone is interested.



Please do, I’m sure that will help some folks quite a bit. I plan to write a full-featured FreeCad post for Fire Control, for myself, if no one else gets to it first (and of course, I’ll upload it for all to use). Having your Mach3 post might make that easier (and then I’ll probably do it sooner rather than later - I don’t really need it, because I’m already invested in both Fusion and BobCad, which it looks like I’ll have to write a post for, as well).

There are actually some really good reasons to run FreeCad, instead of, or in addition to, beefier stuff like Fusion, or Solidworks, or BobCad. Even if you have a paid license for a more advanced CAD / CAM system. I want it for programming relatively simple stuff right at the machine, vs going in the other room to use my CAD workstation, without hanging a $2k laptop on the side of my ‘make stuff with fire’ machine…

Also, I’ve seen several posts by folks who are completely lost after being told they have to start by learning Fusion. Those folks were not expecting the Autodesk learning curve when they ordered their Crossfire… Having good solid freecad posts uploaded for both controllers, will give those folks the ‘better’ answer they came here looking for.


Here is my version of a FreeCad post processor for the Crossfire using Mach3
Unzip it to the …\FreeCAD 0.19\Mod\Path\PathScripts\post folder.

crossfire_post.zip (5.1 KB)

I’m struggling with the toolbits function in FreeCad to create a plasma cutting tool.
In the interim I use an endmill tool with the diameter set to my kerf width.



For the same reasons others posted, I’m changing to FreeCAD from Fusion 360. Downloaded and installed your FreeCAD post processor (THANKS FOR BUILDING IT!) and, after learning a few FreeCAD basics, was able to create a tool for the RazorCut45 torch and generate gcode for a simple shape. Like you, I built the tool with the endmill template with diameter set to kerf diameter. I did a few other things in the Tool Job edit to get reasonable results with the Path Simulation. The FreeCAD Path Workbench ran the simulation and seemed to yield reasonable results. Have not tried to run the gcode on my new CrossFire because it came with FireControl. Wondering how much different Mach3 and FireControl are? Do you think the gcode world work on FireControl?

Gcode is new to me (as is the Forum) but, with the help of YouTube and Google searches I’m beginning to understand a few concepts. For example, I think I understand a few of the things you did in the Post Processorr (e.g., getting rid of Z axis information, tool diameter compensation, running in mm, turning the torch on and off, compensating for tool diameter, etc.)

I’d be glad to send you the FreeCAD file and explain what I learned during the creation of the tool. Since I honestly have no real idea of what I’m doing, I don’t want to share wrong information on the Forum; however, if we could work together we may move the ball down the field a little farther.


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I see that a FreeCAD file can’t be attached per Forum rules; however, I was able to download a couple of screen shots from the simple FreeCAD example (a 2" square with a centered 1" hole): 1. The Workbench Path operations; 2. A screen shot half way through the Path simulation; 3. The gcode generated by your postprocessor.

I studied the gcode and I can see how it would work on a Crossfire. Looking forward to discussing this with you. Haven’t researched Forum rules for off-forum discussion but I personally have no problem doing this. I’d be glad to share my phone number and e-mail once I get a response from you. I would like to talk to you before posting any learnings to the forum.


May 18 - 1 gcode.nc (1.2 KB)

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I’m one of those who have decided to go with FreeCad and am therefore getting up to speed on FreeCad, gcode and Python with the intent of eventually coming up with a FreeCad postprocessor for FireControl. I posted some things below under treefrog’s posts and have been communicating with him about his Mach 3 post. Didn’t want to clutter up this string as I am still early in the process and would just add clutter so I went DM with Leon. I also received some useful information from Langmuir about FireControl post requirements that I shared with treefrog and can share with others if interested. Just curious if you have made any progress on the post for FireControl?



You can upload ZIP files and files that are renamed to “.dxf”. As long as recipient knows what it is and renames it back to a FCStd file then the transfer should work. I don’t see any big issue with the discussion taking place on this forum. You’re in the unsupported category and it is peripherally related to the interests of the members. Of course, I’m not the forum owner so who knows… :man_shrugging:

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Thanks for the tip.