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Joined: Tue Sep 14, 2021 6:43 pm

Sketchup 2017 STL scaling?

Tue Sep 14, 2021 7:19 pm

May be because I'm using a five-year-old version of desktop free SketchUp rather than their "pro" and/or web-based versions, but:

When I use their exporter to create an STL from my model, then import that into S3D, the latter sees it as TINY -- the data's all there but it's postage-stamp sized even if I let S3D "fix" the units. I wind up having to go into the model description and readjust the scale myself, usually by a multiplier of more than 9000. (Having done that I can export the STL to "save" that change, but I have to redo it every time I tweak the model.)

I presume this is SketchUp's fault rather than S3D's... but if anyone happens to know how to persuade SketchUp 2017 to Play Nice With Others, that would be great. Or if there's any way S3D could recognize this particular goof and offer the correct scaling automagically, that would be Nice To Have.

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Joined: Tue Mar 10, 2015 4:09 pm

Re: Sketchup 2017 STL scaling?

Wed Sep 15, 2021 2:07 pm

The one thing you need to ensure you understand is that stl files do not hold any dimensional information.....other than every measurement is a factor on ONE. I n other words, a dimension of 3 is sompy that. It could be 3 inches, 3 mm, 3 sausages...anything.

Once you understand that , I hope it might be clear that there is no error in either Sketchup or S3D. AS to Sketchup scaling not matching S3D scaling, then its a matter of locationg and changing the setting in Sketchup that determines what actual dimension it takes as !....and then changing it so it matches what S3D assumes is 1.

At a guess, you've designe your model in Sketchup on the assumtion that 1 is one yard (well it was designed for 3Ding buildings!!) S3d has a default assumption of 1 being 1 mm. Hence your model that you have designed as 3feet cubed cubed, for example is now seen as 1mm cubed in S3D. Of course, each package sees the dimension as simply...1.

Unfortunately, I don't know Sketchup at all, so can't point you to where the appropriate "setting" is.
Doug Kightley
Volunteer at the National Tramway Museum
Railway modeller and webmaster at

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Joined: Wed May 25, 2016 1:58 pm

Re: Sketchup 2017 STL scaling?

Thu Sep 16, 2021 8:09 pm

Are you using the built-in STL exporter in Sketchup 2017?
I'm no expert but am quite familiar with this version.

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