The following is taken from the original announcement of this puzzle in 10/2013.
This is a little chop using the skirting rails mechanism. It prevents jumbling, so internal blocking due to hidden jumbling doesn’t happen.
I was hoping a 65 mm version of the little chop would be possible. The puzzle is too small to be perfectly stable though, so a larger version is in the works.
This experiment was done with the blessing of Matt Shepit.
To understand the skirting rails mechanism, please see the Pentultimate V2 article, and the Pentultimate V3 article first.
The little chop puzzle has 6 slices, like the Pentultimate. And like the Pentultimate, 5 of the slices can be locked to one of the exposed centers. (Here the locked face is colored red, and any edges that touch that face are colored red, to show that they are locked.)
Only the equator remains to be locked. I chose the center of the cube face to create an interacting nub to collide with the core, indicated here by the green dot.
Here is the core, with a red part added to indicate the colliding nub. We can see that the part will be allowed to skirt in from above and below, but it won’t be allowed to move sideways.
The original article did not include these mechanism pictures:
curious how big the actual sphere (without the cubic end-caps) would be…
also curious if a custom octahedral-little chop might be arranged?
The sphere is about 80 mm in diameter. An Octahedral version would be trivial to put together for you, but would cost about $650 using shapeways.