Friday 18 March 2011

Bill Cutler's Computer's Choice Unique 10

I thought I'd break off from the Revomaze theme to mention one of my recent purchases. Any casual puzzle site surfing will quickly produce the name Bill Cutler, he has been designing puzzles for many many years and they are all rather complex and beautifully made by a true craftsman Jerry McFarland. He specialises in Burr puzzles and other 3D interlocking puzzles. He has undertaken an exhaustive analysis of these puzzles using software of his own design.

I noticed from his website that he had a new batch available and thought "I have to get 1 or 2 of these", followed quickly by "but I've spent a fortune already!", followed even more quickly by "what the hell, in for a penny, in for a pound". So I duly placed an order and they arrived within a week!

I must first say these are really beautiful puzzles, really well made and pretty difficult. The Computer's choice unique 10 puzzle is a standard 6 piece burr but rather than being based on a burr that is 6 units long it is 8 units long (this allows a huge amount of extra complexity). This particular puzzle is supposed to be the most complex 6 piece burr with only one solution. As the name implies, it requires 10 moves to remove the first piece.

 So on the evening of acquiring the puzzle I compulsively had to play and after about 15 minutes had it in the position to remove the first piece. I back-tracked all the moves to make sure I knew how to interlock it again. I did plan on taking careful note of all the piece positions so I would be able to reconstruct it once open. Unfortunately after taking out said first piece the whole thing just fell apart!!

These are really complex pieces and the only information given is a piece of paper labeling them and informing you which ones belong in which spot. After quite sometime fiddleing about I realised that knowing which piece goes where is NOT helpful as the orientation is completely unknown as well as how they initially should be connected!  I had to admit defeat!! This, however, did not detract from the fun for me! I had installed a program called Burrtools, a freeware software, which allows you to design and solve very complex puzzles (it will not cope with piece rotation, but sliding puzzles work very well). I spent a happy hour or two learning how to reproduce the shapes in 3D in the program and then set it to find a solution. After less than a second it found nothing! Now I started to panic!!! If burrtools couldn't do it there was no way I would be able to! On checking my pieces I found that I had left one notch out, fixed it and tried again - still no solutions. I had to resort to the help pages on-line and realised that for a burr puzzle like this (with no solid key-piece) to work, it must have gaps hidden within the structure - but I don't know where they should be. Finally I realised that you can replace some of the interior cubelets in the design with cubelets that can be either gap or solid. Once this had been done I had my solution in less than a second. This is an AMAZING piece of software by Andreas Roever - everyone interested in interlocking puzzles should take a look (it is multiplatform).

It still took me a bit of time to learn how to do it without the solution in front of me. But despite "giving up" I have actually really enjoyed this puzzle and the experience gained with Burrtools. I keep opening and closing the burr and marveling at how something can be so complex from so few parts.

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  1. It would help to know the first piece out. I too am struggling...

    1. The piece to remove is the one that is second right in the picture of the pieces.

      If you are really struggling then Contact Me and I will send you the Burrtools file.