Object proportions are off in the slicer compared to Blender
I modeled an object in Blender intending to print it, but when I import it into PrusaSlicer or Cura, the dimensions don't quite match.
In Blender, the dimensions are 178mm x 142mm, but when I import it into Cura or PrusaSlicer, it imports it as 180 x 138mm. I can manually adjust the dimensions, but why is this happening? And will it mess up my fit in the end? Who do I trust here? I don't want to waste hours printing for nothing.
As mentioned there's no units on STL files so the slicer assumes millimeters but warns you if it thinks the scaling is obviously not right.
My blender units are meters.
If I just export the default cube from blender (which is 2x2x2) and load it up in the slicer I get a prompt saying the units seem to defined in inches. It's assuming I can't possibly want to print a 2mm wide cube. Do I want to convert it to inches?
If I answer No, I get a perfect 2mm cube, good luck printing that.
If I choose Yes, to convert it then I get a cube 50.8mm across. (2x 25.4mm) exactly 2 inches as expected.
Going back to blender, deleteing the default cube and creating another cube but scaled to 0.1m. This time exporting to STL on the export save dialog there is a scale setting: set this to 1000 (to convert from blender 1m units to Prusa 0.001m units). Now the STL is imported into the slicer with no fuss and is exactly a 100mm cube.