Theirs quite allot of storage around but I designed these around my specific needs for stackable storage. I wanted something sturdy, to maximise internal storage space but be efficient on filament quantity and print time. What sets this design apart is where I needed the flexiblity to stack and/or easily attach and remove from the wall. I considered hex, but in my case simply sliding on and off more traditional screws works better for my specific usecase.
I use three sizes which I'll simply refer to as small, medium and large. I have also added all 3 models without the wall mounting as, if like me, you may not intend to mount them all, so giving flexibility for printing ones for the wall and ones purely for stacking saving filament and time.
Dimensions are:
Wall mounting holes are 8mm screw head narrowing to 4mm (counter sunk to 6mm on inside)
Hope these are of use or inspire your own ideas. Please feel free to leave comments and shout if their is anything specific you'd like to me change or offer in these designs. Thanks!