Gcode files created in Autodesk Fusion 360 open but no G2 or G3 codes are processed

LightBurn Software Questions
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1

I have been designing in Autodesk Fusion 360 and creating GRBL-compatible gcode in the Manufacture platform. A simple one looks like this:

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image593×494 35.5 KB

The output from Fusion 360 is this:

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image468×728 18 KB

The simulation in Fusion 360 runs with properly without errors. The tool path for the circle and the square are followed.

When the gcode is imported to Lightburn, the resulting image is this:

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image616×554 4.8 KB

And the saved gcode is this:

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image516×698 13.1 KB

The G3 codes are missing! Feature, bug, or something else? The parts I am cutting out are more complex than this, simple example.
It is clear that Lightburn is moving the origin. Any ideas why the G2 and G3 arc codes are missing? Do I need to paste a block of codes into the Fusion 360 to get Lightburn to interpret the file correctly?

Exporting the Fusion 360 sketch as a DXF file opens correctly, with the hole in the square, but the Lightburn gcode only uses G1 codes for the circle, not the G2 or G3 codes.

2

A few notes:

  1. LightBurn imports g-code only as far as using it to generate geometry. The g-code is not preserved and reused during output. G-code is freshly generated from the available geometry. Any specific g-code from the F360 import is long forgotten.
  2. LightBurn does not generate G2 or G3 arc paths for output. Only G1 is generated.
  3. I haven’t specifically tested it but it appears G2 or G3 is not valid for import either based on your findings.

Long story short, I’d suggest not using g-code as an intermediary format. Stick to DXF or SVG for import. I’ve always seen g-code import as more for debugging purposes.

3

Correct - we don’t support G2/G3 for output or input. And yes, you should really just use DXF. GCode import is, in fact, only for debugging purposes. But it ONLY debugs OUR GCode.

4

Good to know. After posting my question and thinking about it for a while, I came to the conclusion that Lightburn just doesn’t support G2 and G3, now I understand why. Thanks for the help! I’m still relatively new to the world of makers. I’ve been using Fusion 360, a 3D printer and a laser cutter less than a year.

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