Honestly the most complex puzzle I got ever. As it is an edge turning icosahedron, it has 20 turning (half)axes. Each twist moves 49 visible pieces!
THe internal mechanism is quite tricky. To the inner sphere there are connected 20 mushroom/parachute like objects. On the sphere surface there is the layer of mechanical pieces to hold the surface pieces of the second layer.
When I got the puzzle, I had some serious discussions with Sharon and Ray about the mechanical features, as pieces were popping out of the puzzle with each turn. An improvement was to create anew core, which was a little bit smaller in diameter, thicker in its surface and with some internal tubes to hold screws. Matthew designed that for me and I ordered it from Shapeways then. This improved the puzzle quite a lot, as it is now possible to determine the tension for each axis individually. Aside to this a lot of silicone spray was used. Between spraying and the effective inprovement to the piece surfaces two weeks of waiting had to take place before the result was satisfying.
Size: Edge length 5.3cm
External LinksTwistyPuzzles: The Icosacopter By S&Mhttp://twistypuzzles.com/forum/viewtopic.php?t=19418