Cast Coil is the newest of the Hanayama cast series of puzzles, and was designed by Edi Nagata of Japan. Thanks to Puzzle Master for sending me this puzzle to review. The objective of the puzzle is to separate the two pieces of the puzzle by sliding and rotating the pieces around each other.
At 1 1/3 inches x 1 inch, this is a compact little puzzle, which carries a good weight to it. The Silver and Gold pieces provide a good contrast and make the coil design stand out. There seems to be a rather divided opinion on the look of this puzzle. The aged appearance of the metals used gives it a rough and pitted feel, that many puzzlers don’t seem too happy with. Personally, I think it looks great. I really like the aged appearance and think it suits the puzzle. To see what others are saying, read Kevin’s review here and Brian’s review here.
When I first tried to solve this puzzle, the pieces were a VERY tight fit, to the point that quite a lot of force was required to separate the pieces for the first move. That does seem like a temporary issue however as the more the puzzle is played with, the easier the pieces move. Now that I have solved the puzzle many times over, there is a slight gap between the pieces which was not there initially. The first move is still a little stiff, however that helps to keep the puzzle in the starting state, so isn’t entirely a bad thing.
The two very similarly shaped pieces have a number of notches cut out at strategic points on the inside of the puzzle to allow the square pieces to pass each other. The only real differences between the pieces are the locations of these cut away sections, so keeping track of them can be a little challenging. Initially it took me around 20 minutes to solve this puzzle, as there are a number of dead ends on the path towards the solution. There is one move which still catches me out, and even though I now know the sequence of moves, I somehow manage to get stuck at the same point fairly frequently.
Given that most of the moves in this puzzle are rotational moves rather than linear moves, it adds a unique element to the puzzle. The number of possible moves are limited thanks to the shape of the pieces, but rather than making things easier it seems to make things harder as you find yourself wanting to rotate the pieces and being blocked. In all you need around 7 distinct moves to separate the pieces, so once you know the path to take, it can be opened very quickly.
I really enjoyed this puzzle, and think it provides just the right level of challenge. Hanayama rates this as a level 3/5 puzzle, and Puzzle Master 7/10 – Challenging, which I have to agree with. I’d highly recommend picking this puzzle up as it’s a clever design and a fun puzzle.