I have a model of stairs that I want to prepair it for 3d printing. My problem is that the model is a disaster ( has a lot of non_manifold edges and it has to be fixed. So I would like to ask you is there any way to fix that or I have to recreate it from the beginning?
Aside from the bad objects, you have created non-manifold surfaces by making some of the joints in your stairs edge-to-edge instead of overlapping. Not only will this create the non-manifold structures you experienced that will make 3D printing difficult, but you can’t build stuff like this in reality either…