Help An issue about not manifolded models

[Hasanovic 0]

I've wanted to create a Halo cosplay for 3D print. 

Fortunately, I could download that helmet. I cutted the vision and the bottom of the helmet (blender).

 

The problem I have, right now, is that cura prints inside that helmet (yellow parts).

I tried to cut that helmet in two parts but that ain't work :(.

 

Can someone help me how to let those holes be holes?

 

Here is my file:

Helm-ganz.stl

Edited May 23, 2022 by Hasanovic

[GregValiant 1,119]

 

That model has a lot of problems.  Repairing the model causes your new holes to close up.  You need to go back to blender and clean up the edges of your cuts.  Here is a report on the errors:

--> 93 Naked edges (?)
--> 0 Planar holes (?)
--> 2 Non-planar holes (?)
--> 0 Non-manifold edges (?)
--> 0 Inverted faces (?)
--> 0 Degenerate faces (?)
--> 0 Duplicate faces (?)
--> 0 Disjoint shells (?)

It appears that all along the edges where you made the cuts the seams are open.  Cura can't figure out where the outside ends and where the inside starts.