Stretching my Abilities

Stretchy 12 Burr

In mid-February, Juno and Yukari announced that 3 new burrs were going to be put on sale and I instantly jumped over to have a look. There is something special about Juno's work - he has a tremendous mind that seems to come up with brilliant stuff all the time and then, unlike a lot of what goes up on Puzzlewillbeplayed, he critically looks at the design to see whether it has anything specific to mark it out as worth making and us purchasing. Only a very small number of his designs seem to get out into the world for which my bank account and Mrs S are very grateful! Of the 3, I could not resist adding the Stretchy 12 burr to my collection and playing with it fairly soon after arrival.

For those of you who follow me on Facebook, it does look like I buy absolutely everything but believe me, I do choose only puzzles that I think I might be able to solve or that will be fun to play with. My eyes immediately jumped to the description:

This diabolical puzzle requires 15 moves to remove the first piece from the assembled shape and another 19 moves to remove the second piece. 

The puzzle and its pieces have 7-unit length. Just before the first piece and the second piece is removed from the assembled shape of the puzzle, it stretches to a 13-unit length. Every single piece moves during the assembling and disassembling process. It’s quite a transformation of the shape.

Most of the movements follow the X or Y axis but very rarely the Z axis. Find a flat surface and choose a stable orientation of the puzzle and then, you can easily push and pull puzzle pieces.

The fact that a higher number of moves is required for the second piece removal and the enormous changes in conformation during the solve process made it very interesting to me. The kicker, however, is the last paragraph - a burr puzzle that can be solved on a flat surface struck me as something that I really had to experience.

When it arrived the first thing to strike me was the size - this is a fairly large burr at 10cm across in every direction and the fact that it is a mixture of boards and sticks too with boards made from his own home-made plywood. Not just any old plywood (this is layers if American Black Walnut surrounding European Beech - very striking) and the burr sticks are rather substantial made from rather gorgeous PNG Rosewood (aka Amboyna or Narra). Every part of this puzzle is substantial and an absolute delight to fiddle with - pieces are loose and slide easily. The construction is such that it is relatively easy to see inside and see whether certain moves might work or what is blocking a particular slide.

The initial exploration produces some wild expansions of the puzzle which is great fun. I was bearing in mind the X-Y axis claim and found an orientation to explore in. After 12 or 13 moves I was stuck! There were quite a few moves possible with several potential branch points but none seemed to lead anywhere. This stayed on my armchair for play for weeks with me getting nowhere - what was I doing wrong?

I began to get rather desperate! The weekend was coming up and I was at risk of having nothing to write about for you, my slightly less crazy than me, readers. Yesterday evening after a nice day out with "the frightening one" I sat down to watch TV and play with it. At this point, I reread the description and saw the "rarely Z axis" words - Aha! Now I looked afresh at what I had done and at multiple points on my pathway I pulled upwards and pushed downwards with no effect until I saw that if I move this one piece over here...

AHA!

Wow! How had I missed that? It opened up a whole new sequence and my first piece came out. Phew! I might just have a blog post for you. Then it was a matter of discovering how a really large number of moves might lead to the removal of another piece - there were a lot of possibilities but one approach immediately stood out and was successful. Brilliant!

The remainder of the disassembly proceeded quite easily and seemed to remain very stable right up to the end which is very unusual.

The pieces are stunning!

In my rush to disassemble it for the blog, I had not paid any attention to the disassembly order and orientation for anything other than the first 2 pieces and after admiring the beauty of the wood and workmanship, I was forced to resort to Burrtools for the reassembly - but if you are careful then you might not need this yourself.

It is one of the most enjoyable burrs to play with and explore - there is one left on Juno's Pluredro shop and it is well worth adding this puzzle to your collection.

Just made available.

Whilst you are there you might want to consider buying one of the remaining copies of the Grooved 6 board burr #2 which was released yesterday. It looks fabulous and if it is anywhere near as good as the 1st version which I reviewed here and Allard reviewed here, then it will be a wonderful and fun challenge. I couldn't resist and it is winging its way to me now.