How can I repair this mesh?

Hello people,

I have got a simple model of stacked boxes and I intend to print it in 3d.
So I made a boolean union and exported a stl. Thing is that when I open and check the file, it has about 432 non manifold edges.

I then delete these edges but the result is a mesh full of holes. The been trying the commands recommended to solve these issues, but dont, the mesh holes are too big and too many,

Any ideas on how can I solve this?

Mesh.3dm (1.1 MB)

Hi ShynnSup - I guess the way out is to let the boxes intersect slightly and BooleanUnion them - to get rid of the zero-thickness at those locations.


Yes, exactly. This non-manifold geometry trips up the STL format and thus many 3D printing systems. Always either overlap corners like that or separate them slightly.