Hi. I'm trying to use boolean operations in Blender to remove intersecting volumes to lower printing costs. But I often get new non-manifold parts during the process. Do you have experiences/tipps/tricks how to handle this?
The best way to have successful booleans in Blender (and in other apps, it seems) is to avoid them completly. ^_^ They generate crappy meshes, sometimes even crashes, and things get weirder as you do more booleans. If it's leaving internal faces and useless edges, you have to clean that by hand. You could help with subdivide operation, but that makes the model heavier and doesn't guarantee it'll not end bad anyway. Two non exclusive paths you can take instead: minimize overlap by moving around vertices or build the model from the ground up as single (or limited number of) shell(s). Using one or both puts you in control and problems will be zero or easy to fix because you know how the meshes are. Remove doubles, show & recalc normals and select non manifold will be your friends (just like when you have to fix the boolean result by hand...). Oh, remember some formats merge all vertices, so test the final file, not just the .blend (or join the meshes, check, then undo up to the join).