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Cast UFO was designed by Vesa Timonen. I know this because Vesa’s name is the only thing that I can read on the back of the Hanayama Huzzle box. UFO is a sphere trapped within a frame, somewhat reminiscent of Cast Marble (). The frame looks like it needs to slide apart to be separated, but the internal sphere, which can be seen through the hole in the top and bottom, is in the way. The sphere can be rotated within the frame and it appears that the sphere is divided into quarters. The orientation of the quarters can also be changed by rotating any half of the sphere along either cutting plane. Although each of the quarters looks the same, peering into the cracks reveals that the quarters are not simple wedges and that there is some fancy geometry going on that allows the rotations but doesn’t seem to allow it to come apart. Maybe it’s a puzzle.
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I started out with what I thought was a reasonable approach to solving it but I wasn’t getting anywhere. Thinking about it some more, I came up with 2 other approaches to disassembling the puzzle. Alternating between the 3 approaches, I finally managed to get it apart. Once I had it all apart my first reaction was relief for finally getting apart. This was quickly followed by the horrifying experience of noticing identifying numbers on the inside of the sphere pieces, which I failed to notice when taking it apart. I now had 6 pieces staring back at me with no indication of how they were originally oriented. The good news is that once you take UFO apart, it is rather easy to determine how the pieces should be oriented and put back together. However, even knowing the solution, it’s still an effort to take apart.
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Let’s get back to the design. I’ve already mentioned that it’s brilliant and it is. It was obviously designed to be difficult and it certainly succeeded. Once you take it apart, you can appreciate Vesa’s genius for creating these types of puzzles. This puzzle has very tight tolerances and you have to have everything lined up just right to start the disassembly. I’ve seen at least one reference on the Internet that indicated that a pre-production version, was used for testing. This version most likely had bigger tolerances, which would have made it easier to disassemble, resulting in the easier rating.
I will mention that there is a significant clue that I completely failed to notice that would have been a great help in the beginning.
I bought my version of Cast UFO from Puzzle Master and if the more difficult Hanayama puzzles appeal to you, you can get a copy here.
Maybe Hanayama is making up for the opposite error on Vesa's Cast Square puzzle. It is my understanding that its prototype was indeed pretty tough, truly 5/6 difficulty rating. Then something happened during production, the parts were scaled to new dimensions, but the relative tolerances were not properly addressed. As a result, the Cast Square, such as it is, is quite easy to solve, perhaps 1/6 or 2/6.
ReplyDeleteIt would be interesting to learn any other information that other readers might be able to contribute to either of these puzzles.
-Tyler.
Thanks for the information Tyler. I didn't know that Cast Square had a restricted movement component based on tolerances.
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