Stan's Tetrahedron

thingiverse

This brain teaser was created in the early nineteen eighties, likely by Leonard Gordon. Stan Isaacs claims he remembered discovering the interlocking answer to this puzzle and it has become synonymous with his name. It is typically made from spheres, but I constructed it using rhombic dodecahedra. There are two components (colored red in the photos) plus two more that are mirror images (shaded yellow).\r\n\r\nThe pieces can be assembled into an order four tetrahedron in two ways. One solution fits together very well, you can hold it upside down and it won't fall apart. The other solution is made up of two half-pyramids. If you mistakenly print four right pieces (four identical pieces) you will only be able to assemble the second solution.\r\n\r\nA wooden version of this puzzle can be purchased from Kadon Enterprises at www.gamepuzzles.com. It is called the Surprising Pyramid.