So I should be receiving my Crossfire in a few weeks. I ordered SheetCam and have it downloaded but the files I downloaded from Langmuir are in DXF, which my computer is saying I need an app to be able to read/open them. What program is the best to load onto my surface pro to read the DXF file then give me the ability to modify it in SheetCam? Hope this makes sense, I’m just now trying to get this worked out! Thanks for any help!!
You’ve really got a couple of things here.
Sheetcam can read the DXF drawings fine. But you won’t be able to modify the drawing using it. Sheetcam is a toolpathing program. It tells the CNC software how to control the torch to follow the lines and make the cuts.
It creates a file of G-Code that are the machine instructions that is read by Mach 3 (Crossfire) or FireControl (Pro) to move the torch & fire it.
To modify the DXF files you need a drawing (or CAD) program. Your two best options are Inkscape if you’re just doing flat stuff (or parts you can easily cut on the Crossfire). Or Fusion360 for 3 dimensional design. If you use either, save the file as an SVG - it’s a cleaner format and Sheetcam can use that too. Inkscape is a free download. Fusion has a hobby license available.
If you haven’t, you should do the Langmuir tutorial videos. They’ll help you with figuring out the workflow.
Lots of people here using both to answer questions and tons of stuff on YouTube as well.
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Speaking metalically, that is…
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Man, thank you so much for the info. I had already downloaded another program to read the DXF file but I downloaded Inkscape and that one looks like it has a lot more options. Thanks for all of the advice and info.
I haven’t had a chance to watch videos yet but I will for sure.
DXF is an old school format that doesn’t really support a lot of fundamental drawing techniques so it approximates many things. It was great in its time (& it’s a pretty universal standard) but computers are so much more powerful than they were when DXF was originally spec’ed. Inkscape was built for modern compute power and SVG is just about as universal a standard. Curves are smoother, a lot of drawing actions are way easier, node count (which cause CNC machine starts & stops even though for micro-seconds) are way lower & its got get support for bezier curves and Boolean operations. After you get up to speed on it you’ll know why that’s all good stuff.
I still use Fusion for real 3D and the sheet metal functionality is outstanding & very useful if you have a metal brake.
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Don’t do that 
Save the file as an SVG in Inkscape. Then use Sheetcam (import drawing) to define the toolpaths and generate the GCode. If you must have a free GCode utility you can import the SVG into Fusion, define the toolpaths and generate the GCode.
There’s no reason to use DXF unless someone gives you the file (& you can open in Inkscape and save it as an SVG) or because someone asks you for a DXF file because they’re not using more modern file formats. DXF is the lowest common denominator of CAD file formats. So it suffers the deficiencies of being the lowest common denominator too.
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jamesdhatch needs to change his name to jamesisright…if his wife lets him…
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I will have to slightly disagree with you on that. I’ve always used DXF in sheetcam with no problems. SVG’s always gave me issues. maybe i just don’t know how to import them.
Although i do use SVG’s in inkscape.
…and if you don’t, that’s totally cool too, and I genuinely appreciate the SVG hint. Every little bit helps. It just seems like this system has been around long enough (in a single package) that surely someone has streamlined the process by now.
It drives her nuts She claims she keeps track of how many times she’s been right when she & I disagreed about something but I’m skeptical But it does make for some fun - I’ve told her some whoppers she innocently believed & then later repeated to someone who knew better. The kids learned to independently verify anything that sounded too reasonable (best trick stuff are things that sound totally credible).
It all started when we were dating. I grew up Protestant. She was Catholic with parents who were 1st generation Americans (her grandparents were Italian & Polish immigrants). I converted to make getting married a little easier. So she got me with a story about the extra holy water in the baptismal font being given to parishioners at Easter to boil their green beans for Easter dinner. 
April Fool’s is a high holy day at my house.
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note to self do not drink liquids when reading a reply from James…I now need a cloth to wipe the screen…a new keyboard…and a kleenex to wipe my eyes after spitting good scotch out in laughter.
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Are you using standard SVG or Inkscape SVG? Those are slightly different formats. The Inkscape specific version has some embedded info & compression that may be causing your issues. If you do a File|Save As you’ll see the option to do a standard SVG. Also make sure you’re using at least version 0.92 although there is finally a 1.0 version out.
The big problem I have with DXF is it lacks native support for bezier curves. So instead of a curve being smoothly defined by the math, it’s approximated using a lot of short straight segments. That’s why you’ll see lots of nodes in some drawings or when you zoom in or scale a design up the curves get choppy. Polylines are not a good substitute for true mathematical definition of the curve.
That and the lack of consistent units in the file - sometimes they’re there and sometimes they’re left out. That’s why you sometimes import a file and it’s way out of scale.
It’s because it was created decades ago when computer processors weren’t powerful enough to do some of the calculations needed before the user would nod off to sleep.
Still supported by nearly everything but formats like SVG and STL are much better at exactly representing your drawing.
Langmuir tried to use Fusion to do a nice streamlined single software package to do that. Then Fusion licenses started changing (seemed like every couple of months there for awhile). The app kept changing making all the tutorials & videos outdated too. And Fusion can do so much more than just 2D parts that it can be overwhelming. Autodesk (Fusion) invented DXF so their products all work fine with it
Langmuir was working on a complete single app solution of their own if I recall correctly. But that’s a huge undertaking. Not sure if they’re still headed down that road.
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That’s kind of the explanation I was hoping to get, actually. It seemed really unusual that the company would market their product as being for absolute bicycling beginners and then put you in the cockpit of a DC10 already in the air, but with a great manual. LOL
The vast majority of what I’ll be doing is simple 2D designs, gussets, base plates, really mostly basic stuff for a couple of small machine shops in town, and I’ve already got the design aspect down. Thanks again for the advice on saving to VSG as opposed to DXF, by the way.
Anyway, I’ve downloaded SheetCAM and will be playing at figuring out the signup screen in the morning.
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I’ll have to revisit that option then… I do notice extra nodes when I import dxf’s into sheetcam… the less the better.
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The main issue I have with DXF is that it does not support bezier curves natively. As a result, instead of a smooth curve being defined by math, it is approximated by a large number of short straight segments. That’s why some drawings have a lot of nodes, or why when you zoom in or scale a design up, the curves become choppy. Polylines are not a suitable substitute for a true mathematical definition of a curve.
Is it standard SVG or Inkscape SVG that you’re working with? Those are two distinct formats. The best cnc software Inkscape-specific version contains some embedded information and compression that could be causing your problems. When you choose File|Save As, you’ll see the option to save as a standard SVG.
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