Over-functional Siamese

Over-functional Siamese is an improvement of Mike Armburst's Fully Functional Siamese 2x2x2. That puzzle is like Tony Fisher's Siamese 2x2x2, but enabling swapping pieces between the two 2x2x2's via a horizontal 180-degrees rotation. Unfortunately, Mike's design and some later variations have the problem that corner pieces fall out when the puzzle is mid-turn. David Pitcher approached the issue by introducing a clicking mechanism in his version. Alas, also his version allows prying out corner pieces.

A solution is the addition of extra mechanism inside the core of the puzzle. Two elliptical ridges control two pairs of pins that move out and in with the rotation of the top face. When the top and bottom are aligned, then all corners can rotate freely. However, when turning the top face, then the four outer corners are locked in place by the pins. This effectively stops the corners from falling out.

As Mike's and Dave's versions are already called "fully-functional", and this new version adds even more functionality, "over-functional" may be an apt description. The name is also a wink to Tony Fisher, who correctly observed that his original Siamese Cube design is already fully functional.

Watch the YouTube video.
Read at the Shapeways Forum.
Read more at the Twisty Puzzles Forum.

Please order a 3D-printed do-it-yourself puzzle kit from Shapeways at this page (check with Oskar about screws and stickers), or contact Oskar directly if you are interested in obtaining a fully colored, stickered and assembled sample of this puzzle.