About this 3D model

Cube than can be used to assemble perpendicular pieces. The holes go all the way through, and are offset so that a screw can be put into each hole (it can be used in a box corner). The holes were sized so that a #8 screw will "bite" securely without cracking the cube. However I found that some of the cubes I printed were cracking, so now I drill out the holes with a 5/32 bit. The screws fit much more loosely, but still bite the threads sufficiently. They are also countersunk so that a "deck mate" type screw head will sit (nearly) flush. For that purpose, I drill out the hole larger so that the screw passes through freely, and anchors into the surface behind.