Rule no.1 in Sketchup for 3d printing
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The biggest problem in Sketchup is the small sizes in mm range.Thats exactly the most often dimensions for 3d printing.
It seems Sketchup is rounding some floating point variables probably because they are near the limit of number of decimals.
The result is that the vertices of faces are not planar and the model has slightly different dimensions of wanted.Also sometimes the solid tools are producing a non-solid.
The problem is very visible when importing STL model from Thingiverse in mm scale.So the no.1 rule is to scale the model X 1000. So 1 mm is 1 m ,or 1 inch is 1000 inch.
But the model should be drawn from the begin in bigger scale ,or imported directly in m ,and exported in m to STL.
Good luck in 3d printing from Sketchup
David -
Definitely a good practice, David!
My favorite way to scale a model is to draw a reference line near the origin, say 10 mm long. Immediately use the Text tool (not 3D Text) and click on the midpoint of the line. The length of the line is entered by default, click in empty space to save it. This is a reference line.
To scale the model up, use the Tape Measure tool. Click on one end of the line, then the other end, and type 10000, and click enter. Sketchup asks if you want to resize the model, click yes. Do your work, then use the same process in reverse to scale the model back to printing size.
This way is nice because the reference line is marked so you always can tell what the life size of the model should be.
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Hi Marcus,
From my experience there is no need to scale back the model to mm,so risk to deform a model.
In my workflow I just export the model in STL format by selecting meters for unit.
The STL file does not have the information of units,so 1m will be exported like 1.0 ,just the same like 1mm would be if exported in mm.
So my workflow is mm safeStep by step:
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Draw in meters (1mm is 1 m) or import STL file and choose m for unit
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Export the STL file choosing m for unit.
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That will work for some cases where you can specify the print units, but my 3D printer assumes models are in mm by default, so it's easier to have it in mm before importing.
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Hmm, I know is a little bit tricky to understand or explain, but the most 3d printers accept STL files. And STL file does not contain unit information. So if your 3d printer accept STL files, you can use this technique.Your 3d printer assumes that model is in mm and that is ok.There is no need to change units in 3d printer settings.Just in Sketchup and at the time of exporting STL file from Sketchup with the STL plugin.
Example: If I draw an 1mm3 cube and export the STL file choosing mm as the unit ,the STL file will be exactly the same like I draw an 1m3 cube and export the STL choosing m for unit.
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I thought rule number one is to make sure you are using volume objects, not just surfaces. If you have a cube with just one face missing, the software will think it's just infinitely thin surfaces and print nothing.
I'm just getting started with 3d printing, so I may be wrong.
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@voljanko said:
Example: If I draw an 1mm3 cube and export the STL file choosing mm as the unit ,the STL file will be exactly the same like I draw an 1m3 cube and export the STL choosing m for unit.
This makes sense! Good explanation
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You are right ,everything must be solid, but that is Rule no.0
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