D20 Countdown die (dice holder)

thingiverse

I wanted a nice countdown die for playing magic that was highly visible. Figuring, might as well utilize the inside to house actual dice. It measures 3 inches between parallel faces and uses ten 1/4 inch diameter, 1/16 inch deep magnets to close the box. I liked one at http://www.thingiverse.com/thing:105296, but I wanted Arabic numerals in a countdown direction (countdown dice have consecutive numbers next to each other to help track life points rather than random number generation). Large hole files have a slightly larger counterbore to offset overextruding so the magnets fit better. By the way, I used a soldering iron to melt the magnets in – don't do this – the heat seems to kill the strength of the neodymium magnet. D20closed_flat is just a large d20 countdown die.