I've been having a lot of issues concerning importing design files into Openbuilds CAM. Most of my designs are done using Onshape, Fusion360 or Inkscape. In the past I've not had issues importing files into Easel / MakerCAM or even CamBam. My latest result is an svg I re-designed in Inkscape since the dxf (R14) that I exported from Onshape would not read correctly in Openbuilds CAM (no vectors were connected even after editing path's in Inkscape). My current svg seemed to open correctly but after cutting the pieces out using a 1/4" end mill with an Outside Operation everything was 3/4" smaller in the Y axis and 1/2" smaller in the X axis. Checking Openbuilds CAM and Inkscape revealed that OpenbuildsCAM somehow scaled down the dimensions of my Inkscape svg. My only solution so far has been to draw up designs in Inkscape but export them as DXF's (R14) with units set to mm. This is after trying to save Inkscape designs as - inskscape svg, piain svg, AutoCAD DXF R12 and finally AutoCAD DXF14 and opening each in OpenbuildCAM and checking dimensions. The AutoCAD DXF R14 file I haven't done a test cut since I've burned through all the MDF I have by running all my prior failed test cuts. My hope is that there is a simpler and more direct method to make designs with open source software and maybe it's as simple as saving a file in Inkscape in the correct format and then using the correct scaling factors in Openbuilds CAM. I expect someone here has found a solution.
Scaling usually relates to the DPI you export at. See OpenBuilds-CAM/svgparser.js at master · OpenBuilds/OpenBuilds-CAM Most applications default to 96dpi. Older versions of Inkscape used 90dpi (from v0.92 to just before 1.0). Illustrator uses 72dpi. But you can accidentally (or through some plugin, updates, etc) end up on a different default. Adjust to suit what we expect. We have to make some assumptions as SVGs (unlike DXFs) doesnt actually have native units. Pixels aren't so great as real world units, so pixels have to get converted to real-world measurements. DPI (dots per inch) conversions often result in scaling issues - not just in OpenBuilds CAM but almost any application-to-application move of SVGs. Further reading: Units In Inkscape - Inkscape Wiki
