In the Fab Lab we use a CNC software called edingcnc (from http://edingcnc.nl)
Unfortunately the official Inkscape DXF exporter for DXF R12 and R14 don’t generate DXF files that can be used without flaws in edingCNC.
Depending on how you we export it curves are missing, scaling is wrong, an additional rectangle for the page background is drawn and sometimes items are misplaced (at least in Inkscape version 1.1).
(As a quick fix for simple files you probably can fix the scaling factor in the save() method of Inkscape’s dxf12_outlines.py on your computer. It is
scale = 25.4 / 90.0
and needs to be
scale = 25.4 / 25.4)
Because of the issues with Inkscape’s official DXF exporter we use since a long time an extension called Better Better DXF which Axel now updated so it can be used with current Inkscape 1.1. It works great if you convert shapes (like rectangles and cirles) to paths and ungroup everything. It is available on GitHub.
Tim explains it:
Note: There is still an outstanding issue with Grouped objects in Inkscape being exported with incorrect size. As I understand it (assuming the document structure sent to export scripts is substantially an SVG file), transforms are applied at the Group level, which is sort of a container that has the actual drawing objects (and possibly further nested groups) as its children. Guessing that to handle this correctly, rather than looking for transforms at the node itself, it must also maintain a stack of transforms that have been applied at the node’s parent level, and parent’s parent, etc. For now, it is an easy workaround to ungroup everything before export.
You still use an old version of Inkscape (0.9 or earlier)?
Here is the link to the old version of Better Better DXF Export by Tim. You need it for older Inkscape versions (before 1.0).
Credits
A big thank you goes out to
Aaron Spike, Alvin Penner, Bob Cook , Tim Gipson, Simon Arthur, Jean-Francois Barraud, Chris Madsen, Andreas, Linda Moehsmer, Jamie Tremaine
Want to contribute?
(this section will be updated on the GitHub repository wiki https://github.com/Fab-Lab-Fabulous-St-Pauli-Hamburg-DE/InkscapeExtension_BetterBetterDXFOutput2021/wiki)
Good information is in a Blog post with many explanations by Tim who contributed Better Better DFX export which improved former Better DXF export written by Bob which was based on Aaron’s and Alvin’s Inkscape DXF exporter. This blog post by Bob contains also important informations.
The DXF specs can be found here and for R14 here in the internet archive.
Inkscape’s DXF R12 and R14 exporter can be found here on Inkscape’s gitlab repository (filenames start with dxf12 and dxf14).
Probably better than BetterBetterDXF but probably also outdated is BigBlueSaw. The download is right before the comments section.
Another old DXF exporter for OpenSCAD is here.
Very early version of an dxf exporter can be found here.
Finally maybe Inkcut also might be helpful.