About this 3D model
A more or less parametric scad file that allows you to create hexagonal burr puzzles. In the current configuration, you can mostly enable or disable the various notches in a 12 piece setup (4 x 3 parallel bars) using a binary pattern - generating anything else requires a bit of twiddling with all kinds of parameters. But the hex bars and setup should provide a decent start. It also shows how to intrude faces in the hexagonal directions to increase the tolerance. An example is included how to create notched pieces. If you print the attached STL file three times, you should already be able to obtain a solvable puzzle.