May 6, 2010

Mirrorkal Escher and Digits in a Box

I stopped by Eureka recently and checked out some of the new puzzles they just got in. David Leschinsky, the owner of the store, was there, which was nice because he pointed out all the interesting new puzzles they got. I was particularly excited to see some of the new Vinco puzzles.

His 2010 collection has quite a different appearance from his usual puzzles: they are quite nicely finished and some have interesting, rounded shapes. The rounded tetrahedrons look particularly cool. David had a Tetrahedron that had been disassembled, so I got to try putting it back together. It is a four piece coordinate motion puzzle, and I didn't find it too difficult.

I was also quite curious to try out Dual Tetra-hedron, which has quite an interesting appearance. It is also a four piece coordinate motion puzzle. This one was already assembled, so the challenge was to figure out how to get it apart.

After a bit of wiggling, I figured out how to do it, though I didn't disassemble it fully. I didn't study it, but I'm guessing that the mechanism of Tetrahedron and Dual Tetrahedron is quite similar.

I thought about purchasing one, since they are quite cool looking, but they were a bit rich for my blood ($95 and $135 respectively).I liked them, but not quite that much!

Another cool puzzle that I saw was Wausau '82 by Bill Cutler and made by Jerry McFarland. I had eyed this puzzle before on an online auction. I had read that this burr was one of Bill's favorite designs and involved a lock-picking technique. Since I used to pick locks, that sounded pretty interesting and I had been wanting to give this puzzle a try.

I played around with it a bit, but kept going in circles. It is just as well, since I'm sure that it would take a while to put it back together as well! I'd definitely consider getting this one at some point, but didn't end up going for it on this visit. It looks like the one copy at Eureka has sold now, but I think you can still buy them directly from Bill.

Well, enough about the puzzles I didn't end up buying: I did end up buying two. One that caught my eye was a puzzle called Mirrorkal Escher designed by Ivan Moscovich. There are nine cubes, each of which contains a mirror. Two adjacent faces of the cube are clear, and the other four faces have part of an image on them. The frame that holds the cubes also has parts of the images along the outside.

The objective is to arrange the cubes in such a way so that one of five possible Escher prints can be seen. Pretty cool idea, eh? I like Escher, so this was a winner with me. I fiddled with it a bit at the store, enough to tell that it wasn't entirely trivial, so I decided to buy it.

It is an interesting puzzle to solve, you need to use logic to figure out how to position the cubes. It isn't as easy as it sounds, because there are seemingly multiple correct positions for individual cubes. For example, the center piece of the image can be reflected from the edge of the cube to the north, south, east and west of it. However, if you go down the wrong path, you'll end up unable to complete the image with the remaining pieces.

It took me about 15-20 minutes to solve the first one, and each subsequent one took a bit less time as I started to get the hang of it. For $20, I got a good amount of enjoyment out of it. It isn't too difficult to give to non-puzzling folks, which is nice too. My girlfriend enjoyed it as well, and she doesn't typically have the patience for puzzles.

One thing that bugged me about it is the fact that the cubes appear to scratch fairly easily. The display model at Eureka was pretty scratched up, and I noticed that mine started to get scratched a bit as soon as I started fiddling with it. Oh well! At least it is cheap.

The second puzzle I got was another one I had seen online before, Digits in a Box by Eric Harsh-barger. It was his entry in the 2007 Puzzle Design Competition at the International Puzzle Party. The idea is to fit the digits 0-9 in a 5x5x5 unit box.

I really liked the appearance of this puzzle: the box is clear plastic, and the pieces are made out different colored acrylic that has (presumably) been laser cut. The colors chosen are quite nice: blue, pink, lime green, orange, ruby red, purple, teal, gray, white, and brown.

The original competition entry was made out of machined aluminum for the pieces and wood for the box and cost $200. The plastic version is only $15, now that is more my style!

As a puzzle, it is quite tricky: there are quite a few pieces that are dissimilar, which makes it fairly challenging. It took me quite a while to figure it out, but eventually I got it. Using BurrTools, I found that there are 4239 solutions. Many of them are just slight variations on the same idea, but there are still a lot of different solutions.

I have a really hard time figuring out additional solutions once I already know one. Once I know a solution, it feels like the pieces have to go that specific way. I'll have to spend more time working on this one and see if I can figure more out!

Overall, this is a great puzzle! You can get the plastic version from Eureka or from, who appears to be producing them. I think the only downside is the difficulty, but there is definitely plenty of re-playability, particularly if you have a bad memory! Initially it seems impossible, but as you play around with the pieces you start to understand how they interact and can fit together.


  1. I was actually going to email you to say you should check out Digits in a Box. I just got one from Eureka and thought it was something you might like. I guess I was right.

    Eric is no longer selling them direct from QuickBrownFox (the bad news), because he sold the rights to someone to mass-produce them next year (the good news).

  2. I bought a copy of "Digits" directly from Eric recently, and have been enjoying it! My kids (10 and 13) like to play with it as well. It is quite easy to get all but one digit in the box!

    Be careful with laser-cut acrylic, dropping a piece off a table can break it. This happened with another such puzzle, but I think the material was thinner.

  3. Brett: Great minds think alike! Its a cool puzzle for a good price. I wonder what the mass-produced versions will be like! I'd like to see something like LONPOS where they give you a starting position for a few pieces and you need to figure the rest out.

    George: Hah, getting the last piece into any puzzle always seems to be the toughest! Thanks for the tip about dropping acrylic, I'll watch out!

  4. Brian

    I love reading your blog. Are you attending IPP this year? You'll love it there when you do go!
    I enjoy the Escher puzzle too. The inventor is Ivan Moscovich who is a dear friend and brilliant man!
    I see from upper comments that Digits is going to be mass produced. This is good to know as I had it "on the table" for ThinkFun as Eric had given it to me at G4G9. I will now take it off the table. This is great news though as we are currently not looking to produce this type of puzzle and I love it when inventors get their work published.
    Keep up the great blogging!

  5. Thanks Tanya! I have been enjoying reading your blog as well. Yes, I'll be attending IPP! I'm really looking forward to it.

    Thanks for the info about the designer, I'll add it to my entry.


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