Scaling issues between Sketchup and .stl format

I designed a piece that is exactly 8cm in one direction. I exported as .dae and using meshlab converted that to .stl to 3D print. In the past the Sketchup measurement was correctly converted by the time it got to my 3D printer. But with this current model I needed to increase its size by a factor of 25 to get close, but still maybe .25cm short of 8cm. What could be causing the discrepancy?

Share the .skp file so we can see what you’ve got. Why wouldn’t you just export a .stl file from SketchUp and skip the Meshlab step?

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You have an issue with the units somewhere. Multiply by 25.4 (the number of millimeters in an inch). As @DaveR suggested, exporting the STL file from SketchUp directly will save you a step or two.

I have Sketchup 2017. It doesn’t export .stl format directly. Will it be 25.4 exactly? No additional decimals?

From memory I pointed out to you in an earlier thread that you can install an stl exporter from the Extension Warehouse.
I probably also pointed out that saying the latest in your profile is useless for us helping you.


Please complete your profile with that information.

@Box did tell you on March 11th that there is an extension available for adding .stl export to SketchUp 2017. At that time he also asked you to complete your profile correctly.

There are exactly 25.4 millimeters in an inch. Somewhere in your process your model in millimeters is getting imported in inches.

Yes. On a historical note, when I took engineering, my textbook said that there were 25.4000508 millimeters in an inch. That was changed to exactly 25.4 in 1959.


Out of curiosity, which measurement did they change? The inch or mm in order to simplify the conversion?

The inch. At the time, the 1/100 000 s didn’t matter much, and measuring devices were already conforming to the 25.4 standard.

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I got a .stl export extension from the warehouse. It also wasn’t the correct size. Maybe 2.6 times larger than the .stl created from exported .dae that is converted to .stl with meshlab. So still very far from the 25.4 times larger.

Add your .skp and .stl files so we can see where you are going wrong.

Holder(LedgeAdjusted)03.dae (12.6 KB)
Holder(LedgeAdjusted)03.skp (91.5 KB)
Holder(LedgeAdjusted)03.stl (4.0 KB)
Holder(LedgeAdjusted)03TestASC.stl (17.3 KB)
Holder(LedgeAdjusted)03TestBinary.stl (4.0 KB)

Last 2 files were with export extension.

You’ve lost me. The files I checked are all either correct or an exact scale of the size, nothing is some odd .25 of anything as far as I can see.
I open you skp and it is 8cm, I can export it directly to stl and it will open in my printer software at 80mm.
How your printer imports is important. I can alter the settings of mine, but even if you only have the default to work with you just need to see what that is.
Export your shape and change the settings in the export dialog, there is an button Options… next to the export one. You can adjust this up or down depending on your system. Try setting it to meters, export, open in your printer software and see what size it is. If it is tiny go the other way and change it to mm and so on until you get the size that works with your printer.

What is the third file, the first .stl?
That one is odd.

The two stl labeled “test” were two export options given by the stl export extension. The first stl file was converted from .dae into .stl. the long way.

I haven’t changed my 3D printer settings so I’m not sure why this is an issue now.

This is why I don’t understand what you are doing and what result you are expecting.
The dae, the skp and the 2 stl exports are all 8cm whereas the one you have converted the long way is .31m.
What size do you want the stl to be??

I want it to print at 8cm. You say the long way is about 31cm for you? All .stls appear super small on virtual print bed. Not oversized at all.

I can only repeat what I have said before, perhaps in a different way.

Create a 10cm cube in sketchup.
Export it three times and each time change the export settings by pressing the Options button on the export dialog. For one export select m, then next cm, and the third mm. Name each to suit.
Open each in your printer software and see which one is 10cm.
This will tell you which setting you should be using.

Ok thanks.