Wednesday 27 July 2011

Hanayama Cast Radix

Cast Radix
I was not planning on posting this one just now but an astounding thing happened today (25/07) and I couldn't resist writing about it - it's not on the scale of the recent financial meltdown but it amazed me and seeing as it is my blog, I thought I'd share it with you. I recently got the Hanayama Cast Radix from Puzzle Master. Many of the Hanayama puzzles are maze type puzzles and (apart from the revomaze) I am not particularly keen on these as I struggle to be able to solve them except by pure luck and dogged perseverance - I don't seem to be able to systematically analyse them. However, I am a bit of a sucker for take-apart puzzles and was particularly attracted to this one. It has a lovely "organic" shape to it and would make a rather fine ornament. It even has an antique brass finish to it!

This one is rated as 4 out of 6 by Hanayama and 8 out of 10 by Puzzle Master (Demanding). I think this rating is about right - after the Cast Starfish it is quite a nice challenge and took me quite some time to solve. The puzzle is a decent size (6.4x5.7x3cm) and a nice weight too. It comes packaged very well in the usual Hanayama black box, mounted on card. It has been reviewed by Brian on his blog.

The aim, obviously, is to separate the puzzle into 3 pieces. Like all the Hanayama puzzles, no solution is provided but if you need it then you can get one here. When you pick it up one of the pieces separates from the footplate and my first thought was that I could just remove this from the rest of the puzzle as you would with a simple nail puzzle. I tried for a few minutes to achieve this and at this point it becomes clear how beautifully designed this one really is - these pieces will not line up to do what you wish in one direction and if you try the other then the footplate is in the way! Next thing to try is to move the footplate out the way but it slides up and just gets further in the way. So now, at about 10 or 15 minutes into this I am totally enthralled and am jingling away and annoying the present Mrs Sadler (she is doing OK for a first wife!!!)

Gradually things get more intertwined with some lovely winding motions and then we have the footplate on the other end. "Fantastic!" I thought, now it should be possible to do the nail puzzle trick - WRONG! I had read a few reviews and some had complained that it was often necessary to use some force to get a particular move done (although force isn't apparently always required). I had required a small amount of force getting to that position so I was convinced that I had everything placed just right so spent another hour trying to proceed. After the aforementioned hour at this I reset it back to the beginning and put it down for the day.

The next day I try again and this time look for a different way out. Yet another hour passes idly turning it over and over in my hands and it suddenly occurs to me what is required. It is actually fairly easy to get it into position and within a few minutes I have the 3 pieces in a line held together with the footplate in the centre. From here the 2 upright pieces come off easily and in a rather pleasant fluid spiral motion.

Cast Radix Pieces
Immediately, I try to put it back together (having noted the order and position of the 3 pieces). The first moves are easy and then it gets tough to orientate the parts to allow the correct sliding motion. When I do eventually get it aligned I discover about the force people have mentioned!

There appears to be 2 solutions to the Radix - the correct one allows it to come apart in a beautiful fluid movement with no force at all - this one is not at all obvious because it looks like the pieces won't match in this position. I have to say that reversing this fluid motion had proved more or less impossible for me - initially I could only do it if I tried to reverse immediately after the forward motion (i.e. I don't actually fully disassemble the puzzle). The second solution is the one that looks more correct because all 3 parts lock together on matching faces and then with a bit of a forceful push it suddenly moves forward to the linked triple. This solution is by far the easiest to reverse for me and of course requires the same force in the opposite direction. I think it took me about 3-4 hours to disassemble and reassemble the first time - a pretty good challenge. I have now done it many many times and still need to use the forceful reassembly method most times have found that if I invert the puzzle in my hands then I can get it to solve with no force at all!

Incorrect solution
25/7 - I thought (as I wrote above) that there were only this 2 solutions to the Cast Radix - I was wrong!!! Whilst at work I gave this to a friend to play with and left it with him (he has done the blue revomaze and is working on the green i.e. an amateur puzzler). After about 3 minutes I looked up and he already had one piece off and whilst struggling a little with the last move he was practically done! My gast was absolutely flabbered!! It had taken me several hours to do it - how did he manage so quickly?? Then I did a double-take - the first piece he had removed was the base-plate; this shouldn't have been possible. He couldn't reassemble it so I did it my way and asked him to show me what he had done. This is definitely a move which shouldn't be possible - I did wonder whether the tiny amount of force that I had previously used had deformed the puzzle slightly making the illegal move possible (I think this is unlikely as it is a very solid construction). After a short Google I found a YouTube video showing that someone else had solved it this way and had never used the forceful alternative - in fact he had been rather underwhelmed by the puzzle due to the fact that he had never managed the correct solution!

I absolutely love this puzzle - for looks, for difficulty level and for the really fluid movements required (maybe the "organic" description is not that pretentious after all!) If you find yourself needing force then I can absolutely say that it is NOT required.
  • Method 1 is the correct way and needs no force.
  • Method 2 is a minor variant of method 1 and requires a small amount of force - it is quite a nice symmetrical approach in the middle.
  • Method 3 is not the correct way - it is much simpler and has none of the fluid beauty of the first 2 - I think you should still look for it (now that I have told you it exists!!!)

I can heartily recommend it for all beginning and advanced puzzlers.


  1. hey, I've looked around, but I have no idea which solution I've found! can you show what method 1, 2 and 3 are?

    1. If there is no force at all then you have found the correct solution. If only a little force then it is method 1 and if a LOT of force (don't do it) then you have found method 2