Hanayama Cast Padlock

Hanayama Cast Padlock

A quickie today - I had fallen behind on the most recent of the Hanayama puzzles and rapidly caught up in April with the purchase of the most recent 3 of the series from a new UK store run by a nice gentleman by the name of Nic Picot. For those of us here, he offers the best value and postage but for those in Europe you will probably be better of buying from Hendrik Haak or from Tomas Linden. In the Americas then I would definitely suggest using Puzzle Master who have the whole lot as well as a gigantic selection of other goodies to tempt you and in Oz then Brian Young has a great selection plus many of his own wonderful creations.

The original cassette
(pic from the design competition site)

The most recent of the Hanayamas to be released was the Cast Padlock which was based on one of the winners of a Jury Honourable Mention award in the 2014 IPP design competition (London). It was designed by Korean designer JinHoo Ahn and his version, which I did get to play with (but not solve) at the IPP was called Cassette. It was beautifully made from Aluminium with two of the pieces beautifully anodised in matt gold - it was gorgeous.
JinnHoo Ahn has also been responsible for the Cast G&G (which I have solved but not actually reviewed for some reason (despite having a Hanayama version as well as a hand made wooden copy).


Having been greatly taken with the original version most puzzlers were delighted to hear that Hanayama had expressed an interest in making a copy for mass production and after a rather long wait it finally arrived at the tail end of 2015 and took another few months for it to be routinely available outside of the Far East. Hanayama had to make some difficult decisions and to ensure easy production and to keep the costs down the anodisation was skipped and almost as lovely copy was produced.

Rear surface

They renamed it as Cast Padlock and added some features that made it more in keeping with that name (including inscribing the name and adding a key hole). The body of the padlock is made to look like aged brass and the shackles like steel. It is a nice robust puzzle and measure a nice pocketable (this is important!) 4.3 x 3.3 x 2.3cm. I have only seen them in the Asian packaging so far but I'm sure that English boxes will be coming. The level according to Hanayama is 5 on their 6 point scale and Puzzle Master agree, rating it 9 (Gruelling) on their scale from 5-10. No solution is provided but there is one available from Puzzle Master here. So far none of us puzzle bloggers have reviewed this one yet which is surprising and there is just one customer review on the Puzzle Master product page which gave it 5 stars and had a very similar experience to me (in fact he shares my name but I can assure you that it was not me).

The goal is to take the four pieces apart, and then restore the original shape. The interior is comprised of two elliptical pieces, locked together tightly around the circular pieces which would appear that they should easily be released. However, despite looking at it for a while and sort of being able to see instantly what was required, it is just not that easy to actually get it to happen.

My initial exploration made me think that it should be quite simple - just line up the gaps in the elliptical shackles with the semicircular centres and then slide it apart! Oh no! Not so easy - everything can be lined up but the sliding motion is blocked! Hmmm. At this point I was reduced to doing what everyone else who was discussing it on Facebook was doing and just fiddling with it to see what would happen. Several people expressed amazement that they were able to solve it with minimal concentration.....in fact they were able to solve it in their coat pockets! Yes, it would come apart when they were blindly fiddling with it in a pocket. They were then left with the 4 pieces and not only to work out what they did but also how to put it back together again.

Needless to say, I was not so lucky as to solve it blindly. After about 15 minutes I suddenly had an entirely new configuration and it looked promising. I wasn't really sure how I had managed it and in panic I tried to reverse what I had done and that took me another 10 minutes. At this point I could not work out how to repeat it! Not terribly bright - in fact it's amazing that I manage to get dressed in the morning! After a further 15 minutes I was able to make that move as and when I wanted and return to the beginning. I could not get any further however. Over about a week of evenings whilst watching TV with Mrs S and jingling away quietly enough not to receive a Whack! Ouch! I managed to get into a third conformation and again could not work out how I had achieved it and also really couldn't reverse it. I continued to play and try to return to the beginning with no success. During a particularly good episode of "The Good Wife", whilst not watching my hands, I noticed a new sliding motion occurring and suddenly I had this:

Solved! It really is as stunning as that - I had no idea at all how I had done this

The challenge now (which everyone agreed) was to put it back and then work out why it had happened and then repeatedly separate the pieces every time. Having the pieces at least allowed me to work out the arrangement that was needed to slide them together and to work out why the 2 shackles were subtly different from each other.

I could slide them back together but for a very long time could not work my way back to the beginning. I knew what type of moves were required but it just wouldn't happen and the secret to that is effectively the secret to the whole design. It is very clever indeed and only by asking yourself "why are the pieces so loose?" can you fully understand the genius of the design.

I am actually tempted to say that this puzzle should be rated as a 6 out of 6 or 10 (Mind Boggling) out of 10 by Puzzle Master. However it is not quite as tough as the Cast Quartet or Cast Vortex and so maybe it should be a 5½? The worry bead potential of this one is definitely not to be underestimated - I have been playing with it for absolutely ages and I never seem to get tired of it. The correct sequence of subtle moves are just so clever. This one is not really for kids or newbies but any reasonably good puzzler really MUST have this one in their collection. Buy it - at $15 (£11) it is well worth it.

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An Update on the Cast Hexagon

I reviewed the Cast Hexagon last month and was generally very pleased with it but after advertising about my post on Facebook I was advised by 2 very skilled puzzlers that there is an alternative assembly possible. To be honest it had never even occurred to me that this might be achievable and I had never looked for it. A small hint was posted by by Stanislav Knot (a VERY experienced puzzler) and I proceeded to search for a method to put it together. So if you have solved the Cast Hexagon once or twice in the "correct way" have a look at this clue and see whether you can make it another way with the pieces all reversed in their orientation:

Assemblies of the Cast hexagon - thanks to Stan

The new assembly did not take too long but was a fun thing to explore - here's proof that there are two (no, I have not flipped it in an image editor!)

Original solution

Alternative solution

This is another reason to encourage you to buy the Cast Hexagon too!