Sunday 24 March 2013

Twin Box Pentominoes

Twin Box Pentominoes

Primitivo F. Ramos. He also designed the Pack The Podium puzzle, featured on Puzzle Place.

Brian Menold. Online retail shop Wood Wonders. Special limited edition of four copies each priced at US$58. Currently unavailable.

Type & Classification
Pentominoes 3D Packing Puzzle

8.7cm (Length) 8.7x cm (Width) x 6.9cm (Height).

Materials & Construction
The outer box frame sides are made from Paduak while the corners are English Sycamore. The pentominoes are Yellowheart. Construction fit and finish is excellent. The pentominoes fit well and slide smoothly. But because the tolerances are very tight, this puzzle may "lock up" in very humid conditions, as did mine. But half a day or so in a camera dry box solved the problem.

Twin Pentominoes is my second puzzle from Brian Menold. The first is Stacks Of Sticks reviewed earlier in this blog. A very attractive and aesthetically pleasing puzzle. The choice of exotic hard woods creates a very nice colourful contrast, particularly the orange Paduak frame and the Yellowheart pentominoes. Probably this was what attracted me to this puzzle in the first place. Brian made a short run of four copies, each with a combination of different woods but I think this version is perhaps the most striking. This is a fairly large puzzle and feels quite a handful in the palm.

The object is to remove the pentominoes from the frame and reassemble them within. I had read from fellow puzzle blogger Kevin Sadler's blog review that the Twin Box is a very difficult packing puzzle and even he couldn't solve it without help. And so I found out the same for myself as I started to remove each piece. After the first several pieces, I knew straight away I would have a lot of trouble getting them back into the frame later. I was already getting confused by the different orientations of the box as I slid the pieces around and then out of the confines of the box.  Some pieces even had to be moved two together at the same time to be extracted.

Numbering the pieces but still of little use at the end
I decided to mark and number each piece. I even took photos and notes of how each piece slid out on my iPad, hoping this will allow for easier assembly later. But as I discovered later, I had missed a step or two during the numbering, and well...everything came out and was in a mess. All my efforts to document the disassembly for future assembly had been futile.

Re-assembly proved virtually impossible for me. Each time I could get no more than four to five pentominoes into the box before getting stuck. Finally I sought the help of Kevin and he immediately obliged by sending over the solution he obtained using Burr Tools. There is a staggering 11,821 solutions! Difficult to imagine that with thousands of solutions, the puzzle is still so difficult. With the help of the programme, I eventually got the pieces back into the frame in the right sequence...Whew! Using Burr Tools, I also found some solutions which are easier to execute than others.

Difficulty Level
Just two words....extremely difficult!

A really very nice and well-made puzzle. The colours catch everyone's attention. For the workmanship that went into it, very good value for money too. And if you want a really gruelling and ultra challenging puzzling experience (and sleepless nights), the Twin Box will also not disappoint!


  1. I'm glad you like it! I have tried to solve it several times since my blog post and have singularly failed. Despite the enormous number of solutions I cannot put it back together without Burrtools!!!


  2. Yes, very difficult packing puzzle...certainly won't be my last. Now I just need to learn BurrTools!

  3. 12 pieces, none planar? Is that correct? No wonder it is so hard with no planar pieces!

    Interestingly, there are 12 planar pentominoes. I just checked in BurrTools and it says there is no solution using the 12 planar pieces.

  4. Hi George, I am afraid you will have to explain what is meant by "planar pieces". I have very little experience with this type of puzzles and even less with BurrTools.

  5. A planar piece is a 2D piece, in BurrTools you could enter it all setting z=1, if that makes any sense. It could be made entirely by joining squares, but to make these puzzles cubes were used. The "standard pentominoes" are planar, all combinations of 5 squares. If you start talking about joining 5 cubes in all possible ways, you will get the pentominoes, but also fully 3D shapes, the "pentacubes".