I just hit this post by Instructables user Phil B over at Make: Online. It describes the construction of Nob Yoshigahara’s “Dualock” two-step centrifugal take-apart cross puzzle, one of which I built several years ago from instructions in Slocum and Bottermans’ New Book of Puzzles. It occurred to me while I was writing about it that it might be possible to produce a 3D analog of the puzzle, with an additional centrifugal pin detachment step on the third axis. The SketchUp model shown animated above is my first concept rendering. Internal pins (centrifugal locks) and bearing balls (orientation/gravity locks) are indicated in red. Solving would require spinning, rotating on the correct axis, spinning again, rotating on the correct axis again, spinning a third time, and then physically separating the two halves.