This is a box to hold 11 standard sized (16mm) roleplaying dice. For when a 7 dice polyset just isn't enough, this lets you add duplicates of the dice you use the most. I personally recommend one extra d20 and three extra d6s.
The spaces are as small as possible in order to accomodate small printers. That means the d4 doesn't sit flat, but I find it's easier to pick up this way. If you don't like that, or if your dice are a little larger or a bit irregular, try scaling up the X and Y axes.
I've included the FCStd file (FreeCAD) for the plain lid, in case anybody wants to add their own logo or symbol.
I recommend a high infill or extra shells on the lid, to give it enough weight that it doesn't move around when you roll in it!
I printed this with a wood-filled PLA, using a 0.6mm nozzle. If you would like to do the same, learn from my many jams: print at a relatively high speed to avoid the filament cooking in the hot end, and with 0 retraction as reversing direction seems to be a big factor in causing jams with this stuff.
I used an iron and some baking paper to smooth the large, flat surfaces after printing. It works, but don't overdo it!
I strongly recommend lining the inside of the lid with felt. This minimizes the rattling noise in transport, and softens the sound of rolling in the tray considerably.
To complete this project, you will need 8x magnets. I designed it for the ones I had, which were 4.75mm in diameter and 1.5mm tall. There should be enough tolerance in the design to fit 5mm diameter magnets up to 2mm tall.
Comment if you would like me to re-post this with holes of another size, and I'll see what I can do!
My printer has a relatively small print volume (120x125x125mm), and I wanted to see how many standard sized dice I could fit in a box that I could easily print.