How to import metric DXF accurately?

Software Carbide Create
1

My Shapeoko is finally put together, so I’ve started playing with CarbideCreate. My first test was to grab a DXF from a dice box I created in OnShape.

I do most of my CAD design in metric, and I’m used to the import process asking me what units the DXF file is in so that appropriate conversions can be done. Here’s my workflow with CC 431:

  • Create a new document.
  • Set the units to MM, configure some reasonable stock size so I can compare the import’s scale.
  • Import DXF (2010 format, exported from a metric OnShape project).

Based on comments in other forum posts, this should work. Instead, it my DXF is still imported with the units as inches, and then “converted” into metric… E.g. a 10mm circle is imported as 254mm (which is 10 inches converted to mm).

I have no problems using SVG files (I’m used to having to run my DXF files through Illustrator to join lines, etc. for use with a Glowforge) but it would be nice if I could skip some of this extra workflow when using CC.

2

I have the same issue, but realized that it is OnShape that isn’t exporting the dxf correctly. The easiest workaround I just found is to open the dxf in notepad and find the $MEASUREMENT entry and change the 0 to a 1. Seems to work.

In the HEADER section there is a variable $MEASUREMENT (Group code 70) sets drawing units. 0 = English, 1 = Metric.
From the dxf_r14 reference manual.

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