Ball Burr Puzzle

thingiverse

Although it doesn't look like it, this is a variation of the classical 6-piece burr. This version uses six identical pieces and the final assembly has the appearance of 12 balls arranged at the vertices of an icosahedron. The ball diameter is 25 mm. Assembly requires coordinate motion of all six pieces and is quite tricky due to the rounded nature of the pieces. When it does finally snap together, the puzzle is rock solid and can be tossed about. It can be difficult to get it apart. I include two versions of the basic piece, which has been cut in half for easy printing. The basic piece (version 0) uses a cylindrical connector, Version 1 uses a square connector. I have found that Version 1 is easier to assemble. Print 12 copies of "BallBurrHalf_25mm.stl" or "BallBurrHalf_25mm_V1.stl", these halves are then glued together to make the basic piece. The halves contain 2 mm diameter holes for alignment. These small holes can be tricky to print, I recommend slowing down the first layer for these tiny holes. The holes are for alignment of the parts, they are sized to insert a short piece of filament. The holes are off center so that you won't put two parts together with the wrong orientation. To assemble, first make sure each hole is clean and large enough. Then, insert a long piece of filament into a hole and cut it off so it sticks out about 3 mm. Test the pieces to make sure they go together. Finally superglue each piece together. I don't recommend re-scaling the pieces because the holes will no longer be the correct size for a piece of filament.