Import Scaling Issue from Fusion 360

LightBurn 9.0.4
Mac OS 10.14.5

When importing a .dxf file from Fusion 360 the scale is off. From Fusion I export and save as .dxf then open in LightBurn. The imported image is a fraction of the size.

I remember way back when this was an issue and thought it was addressed. However, I can not seem to find anything about this. Any ideas?


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Do you have the same units selected in LightBurn and your source file?

I do, that was one of the first post I found when looking for a solution.

Thanks though!

So not sure why the scaling is off.

DXF files do not store the unit of measure they were created in. If the scale is off, it’s most likely the units being set incorrectly.

How far off is it? If it’s 2.54x smaller, for example, you likely modeled in inches and loaded in cm. If it’s 25.4x smaller, you modeled in inches and loaded in mm.

I’m not familiar with Fusion 360, but generally you want to set any cad drawing to 1:1 drawing units and select unit type for your scale. This has to match Lightburn dxf import scale or you will not get the exact scale imported

It is 10x off. When importing something that is 20mm it comes in as 2mm

Then it’s most likely modeled in cm and imported in mm.

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Hmm just created a 50 mm square making sure mm is default and it imports at 5mm.

I’m not sure what you mean by “making sure mm is default”. AutoCad and others have a “system unit” or something along those lines that is the unit of measure the file is modeled in. The unit that the file is represented in does not have to be the same as the one you are displaying / modeling in.

I’ve been poking around and it seems that Fusion does store the units into the file in a document field I haven’t seen before. I’ll look at my other DXFs and see how common this is, and if I can make it auto-detect, I’ll do so.

Please post the same image (your ‘Settings’ page) as I did above.

This is what was meant about making sure mm was the default dimensioning. This is the only user option where I can find to see what unit is being used. When I import from Sketchup it indeed is at scale.

Just to add that I use Fusion 360 for all my projects and the DXF imports into LB with no issues at all. My Fusion settings are the same as shown above.
There are a few forums that mention a problem:

But I learnt not to use “save as dxf” from the file menu as that can cause problem.
If I am working with a 3D model I select new sketch, then click in the work space and hit “P” for projection. A dialog pops up to ask to select a surface. Click on the surface you want to project as a dxf. This creates a new sketch that combines all the surface in to one sketch. Right click this new sketch from the sketches tree and select Save as DXF from here. It works for me.



Hey David,

Thank you for this information. Similar to what you have experienced, if working just in sketch mode right click on the sketch tree (actual sketch dropdown) “save as dxf” and open in LightBurn. It is indeed imported to scale.

So to recap, File > Export > dxf needs to be scaled 10x. Whereas, right click on the sketch tree and “save as dxf” all is fine.

Thanks again to all that took the time to chime in. Truly appreciated!

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In Fusion 360, Units of Measure can be changed at the “document” level. Even if your default unit of measure is in say, inches, within the “document” you are working on, you can change to whatever unit of measure makes the most sense for what you are doing.

I have updated LightBurn to detect the unit of measure stored in the file if it is present (it isn’t always), and there’s a new preferences flag to enable the auto-detect, so you can turn it off if it gets it wrong.


Thank you! I will try this once released.

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