March 24, 2010

Spinning Icosahedron

While I was down in New York, Brett passed along some puzzles he had borrowed from John Devost, one of which was Spinning Icosahedron (a.k.a. Spinico) made by Stephen Chin.  This puzzle was based on one of a number of icosahedral puzzles originally conceived and made by Wayne Daniel. Check out his article in Cubism For Fun #50 for more information.

The variation I tried is made out of 10 pieces, 5 of which are identical and the other 5 are mirror images. It is an interesting coordinate motion puzzle: you need to expand the puzzle almost to the point of collapse to remove the first piece. However, the more entertaining way of disassembling this puzzle is to spin it on a hard surface. This causes it to almost immediately explode apart into 10 pieces, which is a lot of fun.

Due to the precision required, Stephen numbered each piece so you could identify which location it should occupy. This ensures that the fit will be the same each time: if you swapped the identical pieces around and they aren't exactly identical, it doesn't fit quite right when assembled.

This made it easier to put together, but still it was no easy task. There is a good amount of dexterity required to get the last piece in without having the whole thing fall apart on you. Overall, it is a fun puzzle, but not too challenging. Here's a video of John's son Kyle masterfully assembling the it:



It is nicely crafted, with all the pieces fitting snugly together. The exterior has a nice smooth finish that gives it a nice appearance, it is a nice looking puzzle.

Stephen has made another version where all 10 pieces are identical, which was originally thought to be impossible to assemble. He has also made versions of this puzzle that he has then turned on a lathe to form a sphere or a football shape. Pretty cool!

George Bell has created a 3D printed version of the spherical version of this puzzle that will be available soon in his Shapeways shop under Exploding Ball Puzzle. He is still tweaking the angles of the pieces to get it to work just right, so it isn't available for sale yet. Here's a video of George spinning it:



I think that due to the smaller size, it is a bit harder for the pieces to overcome the friction that holds them in place. It makes you appreciate it all the more when it finally explodes. Surprise!

Thanks to John Devost for letting me borrow this cool puzzle. I had a fun time playing around with it!

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