STL output issue in 2011?

[jon.myers]

I'm not sure if this is an issue with our install or if it is a general issue.

We have a 3D printer and after recently installing 2011 we did a save copy as STL to create a file for the printer.  The part appeared to be much too small.  After doing some experimentation I found that in the Options menu in the STL output our Units setting was centimeters.  When I changed it to millimeters then the exported STL file was the correct size in our 3D printer.  Has anyone else seen this or is it unique to our setup?

Thanks, Jon

[jon.myers]

I should note that to check this issue I used CADfix to translate the STL output to STEP then put the files into an assembly along with the original file.  The STL output in the centimeter setting was 10 times too small compared to the original file.  The STL output in the millimeter setting was the same size as the original file.  We use inches and degrees as our default units in the document settings.

-Jon

[JDMather]

I'll have to do some more checking but with a metric part saved to stl with stl options set to centimeter when I pull the stl back into Inventor it is the correct size.

I know when we send an stl to our machine software we always have to set the units and scale as the software does not appear to be "units aware".

[rdyson]

I've always given the prototype shop an approximate size and they adjust accordingly. I've always been told that stl is unitless.

JD, how are you bring the stl's back into IV?

[JDMather]

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@rdyson wrote:

JD, how are you bring the stl's back into IV?

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I think the add-in is on labs.autodesk.com

I did more experimenting with a 1x1x1 inch block.
If I exported with centimeters and imported with centimeters back into the inch file it was correct.

If I exported with centimeters and imported with inch units back into the inch file it was not correct.

[rdyson]

Thanks, hadn't heard of it before. I'll check it out.

[AustinLiu · Accepted solution]

Sorry for the inconvenience to you.

This is a known issue to us--you have to choose the same UNIT in the export options dialog as the Inventor file when export to STL.

We have noticed this problem and will improve it in the future release.

[Anonymous]

Hi can you explan where to set the export units?  I cannot find the export setting menu. 

This should be a global setting (set ounce and not have to do again)? Or individual part setting (set for every part)? 

My STL files are being exported in metric when the part file is inches (scale is off by factor of 2.54).

Thanks,

Bob Morey 

[Anonymous]

I found the "options" button when I export the file.  It was set cm when the part is inches.  This will fix the problem. THX bob

[JDMather]

See Options before saving.

[jon.myers]

The two places units are set are in Tools - Document Settings - Units tab (for the part) and when you are exporting the STL under options Units.

-Jon