I designed a numerical balanced D20 die that uses number objects for multi-material coloring rather than paint by number like other dice. This includes a 3MF model for the MMU dice and a STL for the single color recessed number die. All numbers are skewed to be aligned flat with the bed for best print orientation when printing in multi-materials. Just open the 3MF in your slicer (have tested Orca and Bambu Studio) and make sure to keep the extra objects as "parts", then select the D20 object and change the color. It is easier to leave the numbers as the first color and set the dice body to a new color. The dice body is name D20 and the numbers are named correctly or use a "_" to denote which part of the number it is.
All test prints were done on a Bambulab A1 mini in PLA or PETG and the max angle is 48 degrees. Tested at 0.12 and 0.16 layer height, 2 walls, 100% infill, and 8mm brim.
- A1 mini print times - Single color PLA - 1:10 hours Multi-color PLA - 0.12 - 13:30 hours (varies by purge amount) Multi-color PLA - 0.16 - 6:45 hours (varies by purge amount) Single color 0% fan PETG 20mm/s transparency test - 3:55 hours
Going to test more MMU dice in the future with PETG/PLA, PLA/TPU, PETG/TPU. Did one test print with clear PETG and green PLA, no issues with the two materials together but it lost adhesion with the bed, and I didn't have enough PETG for another print.
Numerically balance D20 die is based on a paper by Bosch, Fathauer, and Segerman. The point of ordering the dice in this manner is to keep the average roll at 10.5 regardless of any defects in the dice. Vertex sums average 52.5, face sums average 31.5, 20 and 1 are on opposite faces, and average roll over enough time is balanced at 10.5.
Commercial use permitted with attribution. D20 Dice are very common, I just wanted to make this dice easier to print in FDM rather than resin.