I am new to blender but I would have thought that this should be straightforward. I made a cube, and then a longer cuboid which I inserted in the middle and then used the Boolean difference modifier. I changed the orientation of the cuboid twice more to make the other two 'holes' through the object.
Since the operation seemed to go smoothly, I was surprised to see that the holes didn't cut right through the cube, and that in wireframe mode some artefacts were created:
I tried making both objects solid (using the solidify modifier with default settings), but even after making the first Boolean difference operation I can see an unexpected triangle in the model:
Could someone please advise me on what I'm doing wrong?
I am aware that for a simple model like this I could assemble it from cuboids, rather than using a difference operation. However, I would like to be eventually use the techniques to make more complex models for instance a hollow Dodecahedron. Therefore I keen to establish the correct way of making these hollow type models.
I am tempted to try making a new face for each side of the cube and extruding it inwards but I don't know how I would handle getting the inwards extrusions to join up with each other.