Multigrain Burr - Assembly puzzle by Stewart Coffin (STC #275A)

thingiverse

## Multigrain Burr, an assembly puzzle by Stewart Coffin Assemble four unique pieces into the distinctive shape shown in the accompanying photo. This puzzle proves surprisingly challenging despite featuring only four pieces due to its unusual assembly design. It is a larger version of Coffin's Three Piece Block. This print employs "snap joints" allowing it to be printed without supports. After printing, connect all the joints before attempting to solve the puzzle. Attach the piece with eight protrusions labeled "A" to corresponding sockets featuring "A" labels on their interior surfaces so that faces marked with "A" come into contact. Repeat this process for the three protrusions labeled "B." Then, each of the remaining half-cubes with four protrusions will snap into a socket on one of the larger pieces. The joints are designed to be tight and may require force depending on your printer and filament used. If they become too loose or fragile, apply a drop of superglue to the base of the connector for added solidity (though this has been unnecessary with many filaments in my experience). The snap joint concept is further explored in Adventures in 3D Puzzle Printing. This puzzle was created using puzzlecad and I have included the .scad file so you can remix it, adjust size or tolerance, or modify beveling. To do so, ensure you use puzzlecad VERSION 1.1 OR LATER as versions prior to this will result in joints that are too tight – the latest version is available on the puzzlecad thingiverse page. ### About the Designer Stewart Coffin is a renowned designer of interlocking mechanical puzzles who has produced an extensive range of ingenious designs in various shapes and complexity levels. For more information on Coffin, as well as printable models of his designs, visit the Stewart Coffin Puzzles collection. Happy puzzling!