My recent batch of puzzles from Puzzle Master included the Hanayama Cast Rattle, one of the most recent from the very prolific puzzle producing company. This puzzle was designed by Bram Cohen and is rated as 8 out of 10 (Demanding) by Puzzle Master and 4 (out of 6) by Hanayama. I therefore expected this to be a fairly significant challenge this time.
As usual, it is well packaged and the instructions just say to separate the four pieces which make it up. No solution is provided and I think that one is not really needed - most people should be able to work this out eventually. If you do want a solution then you can download one from here. It consists of four pieces each identically shaped that are loosely interlocked together (dimensions when assembled are 40x38x26mm). Being so loose they all can shake about freely (but not fall apart) hence the name - Rattle. The pieces are made from a really lovely shiny chromed metal and the puzzle is fairly substantial weight. It does look at first glance that these should just unlock from each other pretty easily - BUT looks can be deceiving.
I started fiddling with this with the initial idea that I had to find a set sequence of moves to unlock it. It is actually quite awkward to investigate it properly because all the pieces move around so freely that it is very hard to hold things where you want them to be! Initially you just move pieces to and fro, locking bits into various slots that open and close. Over a little time you get a much more complete picture of the shapes of all the pieces - this, because of the very free movement, allows a complete view of all parts (albeit only in short segments). It soon becomes apparent that it is not going to come apart using this technique and once you know the full shape the important thing is to stop and.....
Once I had worked out in my head what was needed, then it still proved awkward to actually do it because the free movement of all the pieces works against you to get everything arranged the way you want them. It is important to have somewhere nice and flat to solve the puzzle on. My initial attempt was whilst watching TV on a sofa with a cat on my lap. First this pisses off your wife (jingling issues) and second it pisses off the sharp clawed cat (ouch!!!) and third it makes actually solving it even harder!!! Finally I got to a desk and was able to get the positions just right and the movement correct and it quickly separated into the 4 parts:
|Cast rattle in pieces|
Overall this is a really clever puzzle and quite different from all the previous maze type puzzles I have tried from the Hanayama collection. It looks great on the shelf and irresistibly tactile. Definitely a good one to buy and to hand to friends - they are unlikely to manage to solve this one unless you give them a fair amount of time with it.