Custom Post Processor

Has anyone here on the Forum built their own custom Post Processor? If so I have some questions!

Post processor for which CAM program? That is vitally important.
To answer your question, yes, several.
Oh I should add, you don’t ‘build’ a custom PP, you modify one that’s close to what you want.

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kind of what a woman does when she marries a man…at least that is what my wife says…


I am absolutely sure your wife made the right choice! :smiley:

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Modifying a Post Processor is what I thought, But I do not know where to begin. As I have mentioned before “I use BobCAD/CAM”. They do not have a Post Processor for the FireControl by Langmuir. I believe they have one for Mach3. BobCAD has been working with me with many questions. They list about 25 or more Processors but none for Langmuir. I asked this question the other night and I got a reply from Langmuir stating that I would have to do as I have been. Draw in BobCAD and then Post using Fusion. I know BobCAD very well and would like to Post there. As many of the Forum members have their favorite software, so do I… I tried to open one of the BobCAD Post Processors but failed.
Langmuir Systems Help (Langmuir Systems)

Apr 5, 2021, 10:09 PDT

Hi Eugene,

We only have post processors available for Fusion 360 and SheetCAM. You can do your CAD work in BobCAD, but will need to use Fusion 360 or SheetCAM for CAM work and post processing.

Can you get the source for the Mach3 post processor? That will be close enough that it should provide a good basis for a CF post. Zip it up and post it here. I’ll take a look at it.

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If you are using the integrated post processor in the newer version of bobcad, you can just right click on the post processor in the cam tree in the upper left pane, and select ‘edit’. This brings up a directory, select the one you want to edit, and right click on it and select ‘edit’ again from the pop up menu. (Left clicking in the folder window selects a post processor from the list for you to use in bobcad.) Selecting edit will open the post in notepad so you can edit it.

I’m sure Langmuir will provide the library for you to use to to edit the post. ‘How to write a post processor’ is a whole different discussion. If you just need to edit definitions (i.e. the post you decided to edit uses different M-codes for THC enable and disable), it’s easy. If you’re trying to change more complex stuff, you might have to know how to write the g-code you want it to output (i.e. write a functional .tap file in notepad to do what you want it to do…). Sometimes the order of the code matters, sometimes it doesn’t.

I would look at the fusion and sheetcam crossfire post files as a template, then open 2 different pre-made posts in BobCad for different brands of plasma systems with the same features (such as the same type of THC - I think crossfire uses voltage), and then you can see what’s different between different software, vs what’s different between different machines, so you can edit the BobCad canned post to work on the Crossfire.

Make sure you ‘save as’ before you start editing canned posts. If things go horribly wrong, you can always reopen the original and start over.

@TomWS and @CadDaddy42 I will see what I can do…