Thursday 15 March 2012

Packing puzzle torture stage 2

After my last post about packing puzzles you would have thought that I'd have had enough!
"Never!" I shout, "I can never have too much torture!Blush!!!

Unhappy Childhood STC#41
Pictured above is another Stewart Coffin design - this is number 41 in his numbering system. My good puzzle friend, craftsman and blogger Neil has spent the last year learning to make wooden puzzles and I have avidly watched his stories of progress and discovery on his blog. In fact I am quite envious of his skills - I do plan to set up a workshop in my garage but at present it is so full of "stuff/crap" that it is impossible. Neil has given a full description of how he made this puzzle here - read it if you have any aspirations at being a puzzle maker - it is truly awe-inspiring!

When I heard that Neil was making one of these, I immediately contacted him to ask him to save one for me. Not long after Christmas 2011 he emailed to let me know that they were ready and after waiting a while to try and get over the Christmas spend, I bought it from him. All the rest sold very quickly on the Puzzle Paradise auction site. My puzzle arrived in mid January and having opted (stupidly) to receive it entirely unsolved, I looked at it with great trepidation and put it on my shelf for later. Every time I thought about doing it, my packing puzzle dread built up and I shied away! Finally, a week ago, at the time I played with the Make room puzzle, I decided to give it a shot. I was also rather frightened because another puzzle pal, Allard, who is a puzzle solving savant has tried to do this and singularly failed! Allard's review is here. Scott Peterson has also made a version previously and you can see pictures of his one at the Puzzle Place wiki.

For other reviews of this puzzle check out Allard's blog - he really loved it. Roxanne did a video review of it on her YouTube channel.

Myrtle burl tray - with signature
This beautiful puzzle consists of 10 pentominoes which have been made from Rosewood and Maple and each is unique. With these pentominoes Neil has made a beautiful wooden tray for them out of Myrtle burl - the markings on this box are stunning. He has even inlaid the base of the tray with the checkerboard pattern from thin slivers of the cubes and signed it. As you can see, mine is number 7 out of 12 made. The pieces were just sitting in the tray with bits sticking out all over the place - so no easy note taking was possible.

The pentominoes can be fitted into a 5x5x2 tray in 19,264 different ways (according to a computer analysis by Beeler)  - although excluding mirrors and rotations brings this down to 2408 possible solutions. So the first challenge for me was to put the pieces into the tray without paying any attention to the colouring of the pieces. The nice laminated information card that Neil provided said that solving the 5x5x2 puzzle in random colours was "Easy"!!! If that is the case then why did it take me nearly 3 hours to put the pieces together into the tray?? Am I truly that crap? Yes!!!

2x3x5 is an "easy" problem!
The computer analysis also revealed that if you checker the piece colours then there are 512 ways to do so but only 511 of them are solvable. Of these 511 solvable colours one of them has exactly one unique solution! So guess which one Stewart Coffin chose to torture me with? I decided that discretion was the better part of valour at this point and looked at some of the other puzzles. Finding a checkered 2x3x5 shape apparently has 15 solutions (it omits 4 pieces) and Neil has labelled the difficulty as "Fairly Easy". I did manage to do this but only after another couple of hours of increasing mumbling of swearwords!

2x4x5 is supposed to be "fairly hard"!
The other "Fairly Hard" problem was to make a checkered 2x4x5 cuboid (omitting 2 pieces) - it has 5 possible solutions. I did try, I promise! But after a while I wanted to break something! I break anything in the house or Mrs S will break me (or parts of me!) and I didn't want to break the sweet innocent little puzzle, so I cheated! How did I make the above photo then? No, I am not that good at photoshop - my excellent puzzle helper Burrtools came to my rescue!

The final problem was to get the pieces into the 5x5x2 checkerboard pattern in the tray. Again, I did have a quick try, but my patience was wearing rather thin at this stage and I gave up in favour of Burrtools. At least I have a truly beautiful and unique puzzle made by someone I consider a friend in my collection and it takes pride of place on my shelf. These have all sold out now - but if you see one come up in a puzzle auction then go for it - it will be a really lovely addition to any collection.

Unhappy Childhood in it's tray - Beautiful isn't it?
Thank you Neil, I enjoyed your story describing how you made this puzzle and I have enjoyed the puzzle itself. The thumb injury was worth it!!! I am greatly looking forward to the next adventure of yours - I am sure my wallet will be a bit lighter again!

PS If anyone has actually managed to solve this unaided then please contact me and let me know what approach you took. I really am trying to improve at these but haven't a clue! I am relieved to know that the puzzle solving machine that is Allard Walker also couldn't solve this one!!!


  1. 3D packing puzzles are hard enough. Adding the color constraints is very hard to deal with for the human brain, I'm afraid. You should try a 2D "checkerboard" problem to see if you find it any easier. I myself prefer "pure" 3D and 2D packing puzzles without the checkering.

    There is a book on 2D checkering puzzles, but I think it is just a catalog of them, but it may include solving strategies, I have not seen it.

    1. George, I agree! Maybe I will stick to 2D packing puzzles (checkerboard or not). Although having said that, I know that when a fine craftsman makes another one I will be a sucker,buy it and then fail dismally to solve it! It will look good on the shelf though!!!

      I do have a lovely 2D one to review - Dave Litwin's breadbox. I solved it in a reasonable amount of time and love it.

  2. Acabo de fabricar las piezas, voy a ver como me va tratando de armarlo; intentaré hasta lograrlo, Un abrazo desde mi bella ciudad de Cali, Colombia.

    1. Good luck! From the much less beautiful city of Sheffield!