Im not sure if Im doing something wrong here or what is happening but about 50% of the time whenever I do a normal boolean difference modifier, if I have at all modified the big object previously, I get this instead of a nice clean cut -
Where that bottom cube sticking out was supposed to be cut away. I have no idea what to do about it and oddly a union cuts a hole, but doesn't make the insides have "walls" so to speak. Ive tried recalc normals and everything here How to cut holes in an object using another object?
But nothing is working. What is wrong? its doing an additive boolean.