Sunday 1 July 2018

Continuing the JCC "Entanglement" Puzzles

Double twist-U - How it was sent out
A better presentation?
Looks trivial? Hell no!
Here I continue my odyssey into the latest batch of puzzles from the incredible Jean Claude Constantin (probably to be exclusively available from Wil Strijbos). The batch of 10 has proved to be a huge challenge! The Spiral-U-U which I struggled to disassemble last time remains in pieces on my puzzle chair and despite 3 weeks of annoying "she who must be kept more than an arm's length away", I just cannot seem to put it back together! Every construction I make just falls trivially apart, no matter how much complexity I put into the assembly process. I know better than to ask Wil for help - remember rule number one of fight club...erm puzzle club?
One of the next puzzles I attempted looked a lot easier. I have named it anatomically the Double twist-U puzzle because of the 2 twisted pieces which look like an elongated standard nail puzzle with a U added to it. The left picture is how it arrived but I was quickly able to move it into a much more attractive conformation which I think is nicer. This puzzle looks MUCH easier than some of the others but is probably about the same difficulty level. The twisted nails are surprisingly interlocked at first and the U really gets in the way. I am always very careful to try and keep in memory the movements I make but, as can be seen from my struggles to reassemble some of them, this often fails. I find that the more complex the shapes are the easier it is to keep orientation memorised but with this, I found it quite difficult. There are a number of initial moves possible but none seem to get me anywhere. The solution was made even trickier by the puzzle consisting of 2 identical pieces so closely aligned. After an evening of play, I had my first Aha! moment:

To be honest, that was not what I expected to happen!
Having achieved this partial solution I backtracked to the beginning again and realised that this was not an easy feat! I did manage it eventually but found that the positioning requires very accurate placement and again, I struggled to remember the exact set of moves. Having got it back I tried to undo it again and even struggled with that! Either I am not very bright or this is a pretty challenging puzzle - I will let you decide which it is...comments below, please. Finally, on my second evening of play, I was able to repeat the process and decided to do the step. This is pretty much what you would expect from an intertwined nail type puzzle except there is an extra twist to it. After 2 days, I had my pieces for photography!

Phew! Unexpectedly hard!
OK! Time to put it back! I had mastered the final assembly stage so expected it to be fairly simple...except it's not! As is common with the better nail puzzles, you are lulled into a false sense of ease with it and don't truly pay attention to the conformation during final extraction (of course everyone thinks that these are trivial). Suddenly I realised that putting the two 'nails' back together wasn't happening. Again we have an "Entanglement puzzle". Eventually, I got it and was able to marvel at the beautiful movement required...that curve at the end of the nail really adds an extra challenge. Having struggled for a while it again took me 20 minutes or so to reattach the U piece. This is a lovely puzzle and really quite challenging - probably a little too tough for a beginner but a nice medium challenge for an experienced puzzler. Be careful, though, it jingles!!! Whack! Ouch!

Balls on rod-U
This is one of my favourite of the bunch. Again we have the experimentation with the U which adds an interesting solution. The addition of a loop of string makes for a more complex puzzle which is rather hard to keep track of movements. It is possible to pull the rod through the larger ball dragging the string loop through it which really makes for some complex conformations. Most of the tangling that troubles a string puzzle is easy to back out of because the loop is short and cannot go very far. Random idle play let me suddenly take it apart within only an hour but with no idea how I had done it:

Easy peasy! Gulp!
It had not taken me very long so in a fit of self-confidence I put the pieces away for an hour which I discovered was a very silly thing to do! Having taken it apart with very little idea of the exact moves I had made, I found myself in the enviable position of being completely incapable of remembering anything about my disassembly. I could barely remember my own name or that of the strange woman glaring at me across the room! Whack! Ouch! To my horror and the strange woman's amusement, I took 3 days to find the assembly. That string is really clever and I am not! I love this one - it is actually not that tough once you know it but finding the Aha! moment took me longer than expected.

The Spira-U-Heart puzzle is particularly delicious for the clever movement that is required for the disassembly. There are 2 features of the puzzle that deliberately lead you astray...these features appear in other types of disentanglement puzzles and are key to the solution but in this one, they do not play a part. This could leave you attempting impossible moves and getting fixated on the wrong feature. Luckily for me, I was not fooled by these shapes and rapidly saw that a different approach was required. I had it apart in about 20 minutes and sat back to admire the rather interesting sequence.

Such complex pieces would be expected to be difficult to dismantle but it's not that bad.
Again, I left the pieces for a while and went back to it after a ½ hour or so. I was certain that I knew the exact sequence but could not get it done straight away. The crucial thing which I had forgotten was that the start position for reassembly is critical and if you cannot quite remember it then it won't work. To my horror, it took me another ½ hour to find the start position and reassemble it. This puzzle is probably one of the best for beginners and experts is not easy but can be worked out with some investigation. It makes a great, if rather large, worry bead!

I have only solved one of the 3 remaining puzzles - that one is rather fun and repeatable too (a future review will show it). This leaves 2 of them sitting on my puzzling chair - I have been working on them for a good few weeks now and, apart from realising that trying the same move over and over again doesn't work, I have been unable to find any way to advance. I'll keep at them until they are might take me months! Many of Aaron Wang's puzzles have been beating me for over a year!


  1. Why do you always say not to ask Wil the solution?
    Have you been you traumatized by him? What did he do to you??

  2. Hi Kevin, how much did each of the JCC puzzles you've reviewed cost?
    Just to know how much to save when Will offer them to buy ;)

    Thanks. Best.