The _angled has some clearance added for easier fit of the pieces together. I am likely going to make some improvements on this design still, thus work in progress. The holes will be under sized for M3 screws at least on my printer, I use this as a benefit and clear the holes on top using a 3mm drill while leaving the bottom part as is. This way I can just use a few M3 crews to close the box when I am using double sided tape to attach the bottom part to frame. Drawn with SketchUp, I am looking for a better (and free) modeling SW. Native Linux support would be cool.