Free the Key

Free the Key

In my recent batch from Puzzle Master I received the Free the Key puzzle made by the company themselves and rated as an 8 out of 10 (demanding). It was designed by Oskar van Deventer and has been available in slightly different form factor from a number of other companies. I think the Puzzle Master version is the only one currently on the market today. It is supplied with a solution (although being fairly stupid, I didn't realise this and threw it away with the packaging before I found out!!!)

It is a pretty big puzzle measuring 11cm long with the disk being 4.5 cm diameter and a very decent weight. It feels fantastic in your hands. It consists of a very large key with protrusions of varying height on either side and a brass disk at the hilt of the key. The disk has slots cut in it of varying heights to take the protrusions. Overall this is a good quality puzzle - the finish is not quite as good as the Hanayama puzzles (there are some casting marks on the key and the brass disk would be nicer with a glossy finish). I think this is pretty good value for money - you get a decent bang for your buck.

The aim is to separate the 2 pieces and then put them back together. No problem I thought, how difficult can this be? They rate this as level 8 out of 10 (demanding) and I think it is probably a 7, as everyone solves it in a fairly reasonable time. However, it is not as straight-forward as it looks; it is not just a case of progressing forwards and rotating the disk one way or the other. There are plenty of dead ends requiring back-tracking, rotating to a different section of the disk and then trying again. The first time I did it, it took me about 10 minutes to take it apart and (shame on me!) about 20 minutes to get back to the beginning.

Free the Key open

There is no way you can work out in advance what to do, it is like wandering through a maze - you have to just wander and see where you end up. If you are mathematically inclined then it has been modelled in Mathematica and a paper written on it (you can find it here).

I have taken this one to work and left it out for all and sundry to pick up and play with. It is so big and shiny that no-one can resist picking it up. Only one person has given up on it (they didn't try for long) and everyone solves it eventually. I love watching people do this - the shock on their faces when they suddenly realise that they have to back-track is just great to see! I first solved this about a month ago and have done it many many times since then. I still cannot remember a solution, I need to solve it fresh every time. This makes for a great puzzle as repeatability is always a bonus with puzzles. I have tried doing it against a clock and even blind! I can do this one now in about 25 seconds and do not need to look at it at all. I do the whole thing by feel alone and it still gives me a buzz each time.

It has met with absolutely universal approval and I can really recommend it to you as a coffee table piece. Even though it doesn't have the finish of the Hanayama puzzles, it is still attractive and has been a big hit with my friends and colleagues. Buy it!!!