Exporting DXF Scaling Issue

[cdamiani]

When I export a part from Fusion 360 to a dxf and open it in AutoCad the scale is wrong.  The same thing happens when I open the DXF in Vcarve Pro.  Seems like a Fusion issue.

[jhackney1972]

If you check, you will find the dimensions are correct, number wise, but the units have been changed.  Fusion works on centimeters if you use the Export function.  You will find the ratio is 2.54:1 between the Fusion model and the DXF.

[g-andresen]

Hi,

that´s what I see:

günther

[cdamiani]

How can I correct the scaling. You would think Autodesk would fix this
issue by now.

[g-andresen · Accepted solution]

Hi,

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@cdamiani wrote:
How can I correct the scaling. 

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if you want to "export" a sketch do it this way:

and not via file > export! 

günther

[HughesTooling]

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@cdamiani wrote:
How can I correct the scaling. You would think Autodesk would fix this
issue by now.

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What and how are you exporting? From all my tests exports whether using Save as DXF or exporting the whole model, the file contains unit information. As long as the program opening the file reads this info the scale will be correct, I'm surprised AutoCAD is getting it wrong. Can you attach an example file, you might need to ZIP it to attach it to the forum.

Note. Save as DXF will export in the current document units whereas export will save in CM. The exported file will have units information stored in it so any program opening can read this info.

Mark

[jandolina]

My imports into Illustrator are all tiny. I am trying to figure out if my problem is from the Fusion Export or from the Illustrator import. There are no export options from Fusion, so it is hard to track down. I have a 10" circle dxf and no matter how I try it always winds up at 10px in illustrator. I tried attaching the exported file, but I got the following error:

The attachment's circle10.dxf content type (application/x-dxf) does not match its file extension and has been removed.

[HughesTooling]

@jandolina  Are you using Save As DXF from the right click menu when you click on a sketch in the browser? If you are the DXF will export using the current document units, so 10 inches if your document is inches. The unit info is stored in the DXF file so any scaling problems will be down to the receiving program.

Mark

[jandolina]

Mark,
Thanks for the reply. I am using the right click, save as function. I am
waiting to hear back from the forums on the Illustrator side. Is it a
concern at all that the file in question didn't validate as proper xml when
I tried to attach it to my original post?

[HughesTooling]

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@jandolina wrote:
Mark,
 didn't validate as proper xml when
I tried to attach it to my original post?

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Do you mean DXF? The forum only allows a few file types, DXF is not one of them so you need to ZIP the file then attach the ZIP file.

Mark

[stevewilkin]

I'm having the same issue.

I've tried importing DXF files, exported from Fusion 360, that have previously imported into Illustrator 2021 without problems and these also come in very small. Adjusting the import options (scaling and units) in Illustrator seems to have no effect.

I also tried creating a test square 50x50mm in Fusion, exporting tha using the "Save DXF for Laser Cutting" plug-in. that imported with a dimension of 17.6x17.6mm.

Very weird! 

[megaplow]

It looks like it is an Illustrator bug. I posted here and on the Adobe site. The other post has lots of people seeing the same issue. Adobe said you can install the previous version as a work around.

[LeeWhitemore]

I also have an issue with DXF. I am using the method of create sketch of the shapes I want and then  save as DXF a 100x100 square comes out at 2540mmx2540mm. i have come from solid works and never had this issue i need to send some drawings to my local laser cutters but he opens them they way too big.

some help would greatly be appreciated.

[stevewilkin]

I’m not an expert on the DXF format, but I think what’s happening in your case is the following:

DXF is a unit-less format, which means it doesn’t store which measurement system you used to create it (mm, inches, pixels etc), just the numbers.

This means that if your laser cutter is importing the file without specifying the units that you used in creating it then it could scale incorrectly. In your case it looks like the importing program was set to inches so it read your 100x100 as inches, which would translate to 2540x2540mm.

The way to ensure this doesn’t happen is for you to import the file into, say, Adobe Illustrator (not the 2021 version, which has a scaling bug). In Illustrator the ‘Place’ option under the file menu has import options which you see by checking the box at the bottom of the Place sub-menu. This gives you options for selecting the units and the scaling factor. So in your case you would select ‘Original size’ and 1 to 1 in mm.

Save the file as a native illustrator file, or better still a PDF, then the laser software should see the size you intended.

[HughesTooling]

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@stevewilkin wrote:
I’m not an expert on the DXF format, but I think what’s happening in your case is the following:

DXF is a unit-less format, which means it doesn’t store which measurement system you used to create it (mm, inches, pixels etc), just the numbers.

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Actually that is wrong, there are a lot of programs that don't set the units but AutoCAD has had the ability for years. The unit information is stored in DXF files exported from Fusion, the variable $INSUNITS is set to 4 for mm. You can test this in Fusion, setup a design in inches, export a sketch using Save As DXF then import into a design set to mm and the size will be correct.

Mark

[jandolina]

There are a lot of people responding to this post on the Adobe and Autodesk
sites. I posted on both. It seems like a bug with the Illustrator import.

Joe

[stevewilkin]

That’s useful to know, Mark, thanks.
But I think a problem can arise when the non-Autodesk program importing the DXF file is not reading the units information, or it’s set incorrectly. In the case of a 3rd party contractor, like a laser cutter, this can result in an expensive mistake.

[s3854896]

This isn't at all solved for me. 

Which ever method I use to export DXFs, either directly from the sketch or from drawings, the scale is completely skewed when opening the DXF in any third party software (have tried 5 different packages all showing the same skewed results).

I'm utterly blown away that this is an issue. And one that there seems to be no response for. How can that even be possible for such a critical component of the software? What is the point of having all of this amazing design power if you can't send files to machines to get cut at the right size?

Mind blowing. Never had this issue with Solidworks. 

[jandolina]

I believe this bug is on the Adobe import side. If you roll back to the
previous version I have heard it works.

My workaround is scaling inside the app after the import.

[HughesTooling]

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@s3854896 wrote:

This isn't at all solved for me. 

Which ever method I use to export DXFs, either directly from the sketch or from drawings, the scale is completely skewed when opening the DXF in any third party software (have tried 5 different packages all showing the same skewed results).

I'm utterly blown away that this is an issue. And one that there seems to be no response for. How can that even be possible for such a critical component of the software? What is the point of having all of this amazing design power if you can't send files to machines to get cut at the right size?

Mind blowing. Never had this issue with Solidworks. 

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How are Autodesk supposed to fix a third party's program that isn't reading the DXF correctly? Here is what I get exporting a DXF to ZW3d. As you can see ZW3d reads the unit info and scales the sketch correctly. Your mention of Solidworks is quite funny as they don't actually set the unit info correctly in their files, they only set the $Measurement variable to either 0 for English or 1 for Metric but English what inches, feet, yards, miles?! Fusion's DXF files are correct so you need to report the bug to the third party developers and point them to this document,  page 47 might help.