Blender model won't produce valid stl for printing I have a relatively simple model to which I've added a lot of modifiers in blender. When I export to an STL the result has several solid layers that aren't visible in blender. I It also thinks that some areas are filler when they should be empty. The blender file is also showing as solid a feature (Axle drive) that I intended to cut of the edges of the enclosure.
My blend file https://drive.google.com/file/d/1XEmOR5hM-he4SAkGam6e8ZCfvHgDv1s-/view?usp=sharing
The resulting STL file https://drive.google.com/file/d/1S5uGJHNUtQJroOG6Ug1dv5IFhWZa3VEE/view?usp=sharing
I have checked for non-manifold edges, merged by distance, recalculated the normals, etc. Any idea how to get an STL that matches my model?
UPDATE: To simplify troubleshooting, I am focusing on just one mesh. I started with a plane and built it up to function as the main enclosure. It is made up of only 81 verticies and 57 faces. The 3d-Print toolbox says that 46 of those faces are zero faces. I have been trying to figure out what that means and how to fix it, but I can't figure it out.

I'm not sure if this is impacting the STL slicing, but that's one problem I'm trying to figure out right now.
2 problems I can see straight away with your model.
First off, the part &quot;base enclosure&quot; has backwards normals. This plays havoc with booleans when they get applied during export and with slicing programs. Pretty sure some of your boolean parts have bad normals also because when you apply all the booleans there are still many bad contiguous edges found by 3D Printing Toolbox. Selecting all in edit mode and SHIFT-N fixes that. Also, select all vertices and merge by distance has over 400 verts that are duplicates, also bad for 3D printing.
Second, your scene is set up to export 1000 times smaller than what you draw at. It's a common mistake when setting up for 3D printing. You need to change your Unit Scale to 0.001, then scale up your model by 1000.

After fixing these issues I could slice it with no problems in PruserSlicer.