Geometry:
HeliPrism 9 Ball is similar to my HeliPrism 6 Ball puzzle, but three additional axes have been created at the 60 degree edges of the prism. The puzzle has a total of nine axes, one at every edge. Moves on these 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. Use a hair dryer or other heat source to get the curved stickers to conform to the spherical surfaces.
Screws: Nine 12mm M3 pan head screws required, available in hardware stores or on the web.
Springs: Nine springs needed, available in web puzzle shops. I get mine from HK Now Store.
Degree of Difficulty:
Assembly: Inside-out core requires moderate dexterity to assemble.
Solving: Very difficult to solve.
Playability:
HeliPrism 9 Ball turns easily, and the mechanism is stable.
Have fun!