CNC Torch CAM File Generation

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  • Here is one video for how to update parts in LibreCAD, the 2D CAD software, by generating DXFs in FreeCAD, and then importing them into LibreCAD:


https://www.youtube.com/watch?v=DTDegM-3Wtw&t=15s

  • However, the next step would be to generate DXF files in FreeCAD, and then working them in Inkscape, as it appears that LibreCAD is hpelesslly buggy on Ubuntu 16.04, Dell Precision M6500. I could not import files into the master CAD file in Libre CAD - therefore I could not nest them on a sheet, and thus I had to provide un-nested DXF files to the CNC cutting service. This added to the turnaround time.
  • The ideal workflow in FreeCAD would be to select all the faces for which we want DXF files in FreeCAD, and then FreeCAD would automatically take you to a Nesting Workbench - where you can drag the DXFs around to next them on a metal sheet of selected proportions. At first, the Nesting Workbench would do the nesting automatically, and then the user could move things around as needed. And finally, the nesting workbench would draw the toolpath, and then export the Gcode.
  • For refinement of G-code - we have typically added pauses at certain points for preheating time of CNC oxyfuel or plasma torch. Indeed, preheating is more effective when small circles 3/16" diameter are made with the torch during preheat. This should be built into the code, at least for 1/4" or greater thickness steel - (1) selection of dwell time should be made based on thickness of steel, such as 2 seconds for 1/4" steel, 7 seconds for 1/2" steel, and so forth.