Geometry:
HeliPrism 9 Curvy is similar to my HeliPrism 6 Curvy puzzle, but three additional axes have been created at the 60 degree edges of the prism. Interestingly, the square faces of the puzzle exhibit true four-way symmetry, even though the curvature of the two types of cuts are different. The puzzle has a total of nine axes, one at every edge. Moves on the nine axes can be combined in any order. This makes the puzzle very complex as it jumbles and shape shifts constantly.
Other Items Needed:
Dye: If you want the puzzle to be black, you can save money by dyeing the pieces yourself with a nylon dye such as RIT or Dylon. Or Shapeways can dye the parts for you at an additional cost.
Stickers: Template available in the instructions forum. If you want professionally cut stickers, I recommend Oliver’s Stickers.
Screws: Six 12mm and three 10mm M3 pan head screws required, available in hardware stores or on the web. (Yes, you really need three slightly shorter screws to get the core together).
Springs: Nine springs needed, available in web puzzle shops. I get mine from HK Now Store.
Degree of Difficulty:
Assembly: Inside-out core requires some dexterity to assemble.
Solving: Extremely difficult to solve.
Playability:
HeliPrism 9 Curvy turns easily, and the mechanism is stable.
Have fun!