Standard six piece burr puzzle

thingiverse

The Original Six-Piece Burr Puzzle:\r\n\r\nConsidered the ultimate puzzle, its origins are shrouded in mystery, but it's been around since the 18th century or possibly even earlier. The challenge lies in determining which of the over 100,000 variations is the authentic standard six-piece burr.\r\nThis enigmatic puzzle consists of six intricately notched square sticks that form a unique interlocking structure of three perpendicular pairs. Upon assembly, all notches are hidden from view, resulting in a seemingly symmetrical puzzle. This characteristic is fundamental to all totally symmetrical puzzles - it's impossible to distinguish between identical pieces when the puzzle is rotated.\r\nEach stick interacts with four others, necessitating a notch on one or more of them. All notches are precisely crafted in discrete units that are half the size of the sticks.\r\nA total of 25 distinct pieces make up this set of notable pieces, all featured in this model for your reference. Each piece bears a unique number etched into its side and can be combined in various puzzle configurations, numbering in the thousands. You can explore more puzzles online, but here's one that stands out - Burr #305, consisting of pieces 6, 12, 14, 21, 22, and 23.