Hanayama Cast Key Ring

Cast Keyring

I received the Hanayama Cast Keyring from Puzzle Master in Canada. It is rated as Level 6 (out of 10) by them and on Hanayama's own scale up to 6 it is rated as a 2. I personally agree with this rating - it is considerably more tricky than the previously reviewed level 6 (2) Cast Key II. In all it took me about 45 minutes to solve this and understand it.

Again it is very well packaged with rudimentary instructions on the box and no solution is given (if you need one then find it here). Once taken out of the box the first thing to strike you is the shear size and weight of it (it is 31x41x95mm). This is one very well made puzzle - it consists of two pieces of oval metal with a gap at one end of each and some odd notches. One piece is shiny chrome and the other is a shiny brass colour. It looks stunning! Engraved on each piece is an ambigram (a pair of words that will read the same viewed right way up or upside down) saying Key Ring. The aim is to separate the two pieces and then put them back together to remake the ambigram. It was designed by the brilliant and very prolific Oskar Van Deventer.

My initial play revealed that the pieces slide along one another and then can turn around if allowed by the spurs and grooves along the edges of each piece. The first move is pretty much constrained but thereafter it becomes obvious that more than one option is available. With a hint of dread I think about plotting a decision tree but discard the idea because it is only supposed to be a relatively easy puzzle. I annoy my wife by playing with it during the nightly news program on TV!
"Do you have any puzzles that don't clink?" she asked.
Unfortunately for her most of my recent acquisitions are metal!!

After just 3 moves I think I have it solved and with disbelief I slid the open ends onto each other. To find that they lock at this point! A closer look at the two open ends reveals that they must be oriented a certain way i.e. one of the pieces needs to be flipped on it's long edge. Hmmm, now it gets tricky. I see no real way to actually work it out by looking at it - so it is down to trial and error with the hope that I can keep track of my moves (I do ensure that I keep one piece in a fixed position and only move the other one to try and keep track). I end up in a cycle in which I go back and forth between the start and the locked position. What is more, several different pathways seem to achieve the same effect. All of a sudden the pieces separate and as usual I have absolutely no idea how! Strangely it only takes me a few minutes to reset it. Again, without knowing how! Have I told you before that I'm not particularly bright? Well it takes me another 30 minutes before I discover the secret move required. The puzzle is solved in 7 moves. All in all it takes me about 45 minutes to completely understand the nature of the "beast" - pleasant without being too mind-boggling. The secret move is not really hidden but to me was not obvious, probably because of the way you place your hands to manipulate the 2 pieces.

Separated pieces

I did enjoy this puzzle for the looks and the small challenge. It is quite similar in nature to the Cast H&H which is a much more gruelling puzzle - I suspect that I would get bored trying to work my way through that one. If these pathway/maze puzzles are your thing then consider getting both.