Part of my model not printing?

[Mdims 0]

I am printing a box and in the box it has a drop down layer before coming to an opening at the bottom. However when i attempt to print it, the preview shows the entire middle layer "greyed out" and not printed. How can i fix without redesigning the entire print.

[gr5 2,178]

Short answer - it's 98% chance there is a problem with your model.  Many cad software are more meant for creating 3d gaming or immersive environments and don't worry about physical reality so the objects are not solid.  Cura either gets confused by too many or too few triangles/surfaces or sometimes makes the wrong (arbitrary) choice.

 

We call it "manifold" when a 3d model is solid.  The most common issues come from blender or sketchup which are designed for graphics/videos but not solids.  Both of these packages have fantastic plugins and features to make your model solid.  What cad are you using?

 

Cura also has a plugin that can test your model.  Please post your STL file and someone might analyze it for you.  But you probably have extra walls or missing walls somewhere.  Or the "normals" are backwards (again - common in Blender and Sketchup but rarely happens with normal CAD that creates manifold parts).

 

For the Cura plugin that can give you hints as to the issue (shows bad normals or missing/extra walls in color), I'm not home but click on "Marketplace" button and make sure you aren't on materials tab and look for "mesh tools".  I think it can also fix the normals for you (the plugin).