The Crammed Cube is an internally geared twisty puzzle that expresses the Mathieu M11 group over its 12 edge pieces. The puzzle features a modifiedCompy Cube mechanism with 6 axes that would normally have 11 moving edge pieces. It is called the ‘Crammed Cube’ because, while the axis system would normally have 11 moving edges, I’ve crammed an extra one into the red/white edge and lifted the corner angle to make space. This edge duplication is necessary to make the group actions fit over cubic geometry.
The Fano Gem is a twisty puzzle that I designed to showcase the symmetries of the Fano Plane, which is a familiar object in combinatorics, coding theory, and algebra. The Fano Plane is the smallest possible finite projective plane, constructed from 7 points and 7 lines, where each line contains exactly 3 points.
From the red face (pictured left), the numbers on the corners of the puzzle match up with the numbers on the plane (with number 7 on the back of the puzzle, out of view).
A comment on my last YouTube video pointed out that the SL(2,3) group expressed by the Quaternion Cube is isomorphic to the group formed by multiplication of the unit Hurwitz quaternions.
There are five different orders of unit Hurwitz quaternions: 1, 2, 3, 4, and 6; On the puzzle, the order represents how many times a sequence must be repeated to return to where you started.