Kanji D20 Dice

I3 MK3S

No

8~12%

Neither the bowl nor lid typically require any support material to print cleanly. Slower printing speeds help reduce ringing/ghosting on the flat faces of the dice. On a Prusa MK3S, be careful about overheating the extruder, as slow fine prints can exacerbate the problem and cause a soft jam until the extruder cools. Be careful to avoid excess heat on the bed causing elephant-foot expansion, and that the magnet holes match the expected interior diameter for the magnets you're using.

Use common 4mm radius x 2mm neodymium magnets in all ten holes. Be sure to get the N/S orientation correct so that the lid will close without all magnets attracting and no magnets repelling each other. The holes are specially shaped to give good press-fit holding power and should fit the magnet just shy of being flush against the walls. I chose to alternate the orientation such that the lid will only properly hold when the "1" is correctly opposite the "20" face, and there are small matching divots on each rim so that you can easily see the correct rotation to close it correctly and quickly.

How I Designed This

This is an original design in Blender, rather than a remix of anyone else's model, even though the final result is quite similar.

The outer and inner dodecahedra, the rims, the holes and the digits are all simply boolean-combined from simple primitives with minor tweaks to make them more printable and robust for holding magnets very firmly.