Export to .STL Format In Correct Scale - Inches I've tried and tried to 3D print models that I have created, and I need them in .stl format.  When modeling in Blender, I change the units in Blender to Imperial - Inches.  However, whenever I try exporting it, it becomes super small.  I don't even know that checking &quot;Scene Unit&quot; helps.  I figured out that if I scaled it by 100, it would appear as corrects scale in Fusion 360, but then I try printing it and it's way bigger than it should be.
How can I know for sure that it's gonna print at the right size?  Is there a way I can double-check?
By default Blender uses 1 unit = 1 meter even if you change the units in Blender to Imperial - Inches. That change only affects the GUI display, not the internal representation. According to Wikipedia, STL is unitless so use a scale of 39.37 to convert from meters to inches when you export, or tell the program you import into the file is in meters.
Basically, in Blender's Scene tab, set the Unit System to whatever you're comfortable with, choose whatever length you like, but leave &quot;Unit Scale&quot; set to 1.0. This leaves Blender internally using Meters, this is a good thing, because the unit system is a little strange sometimes.
When exporting your STL, set the Transform Scale to 39.37 (to convert meters to inches) and don't bother with &quot;Scene Units&quot; check box, it multiplies by the value in &quot;Unit Scale&quot; which we purposefully left at 1.0.