Hart's Cube Puzzle

thingiverse

The puzzle was designed by George Hart and published on his website, specifically at http://georgehart.com/Puzzles/CubePuzzle. It consists of two identical pieces that match up to form a cube when one piece is turned in relation to the other. The two pieces are separated by cutting the cube with a helicoid surface. This code models a puzzle cube similar to Hart's, but it's based solely on his description and images, so it might be slightly different. The hardest part of coding was dealing with a constant gap between the pieces. I'm grateful to Rudolf Huttary for his clever solution to calculating the helicoid offset, which can be found at http://www.thingiverse.com/Parkinbot/about. The STL files were generated for a 50mm cube, and the code has customizable parameters that allow you to create your own variant. Print Settings: Printer Brand: MakerBot Printer: MakerBot Replicator 2 Rafts: No Supports: No Resolution: 0.3 Infill: 20% Notes: There are no special printing requirements, but the gap between the pieces might be a concern. The STL files were generated with a 0.2mm gap, so some trial and error may be necessary. Another option is to print both pieces already assembled. However, I haven't tried that method yet, and it's not clear how they would separate after printing. A bigger gap might be beneficial in this case. The file CubeScrewAssembling.stl was intended as a tool for visualizing the piece match, rather than a printed object. It can help users understand how to assemble the pieces using Thingiview. I'd like to thank Helena Leitão for printing the model in PLA for me. Post-Printing: After printing, I had to file the pieces slightly to achieve a good fit and smooth movement. Be careful not to file too much, as the pieces may become loose with use.