Spinner D20. The dice by the original author had some issues… the numbers hovered above the dice, they hung off the edges of gears, and the top and bottom of the gears weren't completely flat. All should be repaired now. 

If you want to remix this, I recommend all the D's, (6, 4...), all 1's except a single 20 (the DM Special), unfair dice, etc.

If the gears are too tight, use negative Horizontal Expansion. You may need to pop each gear loose by pushing on the bottom. Also, if you use PETG, a bit of lithium grease can help. Don't put SuperLube grease. It makes the plastic stick.