**Ice-9 by David Pitcher**

This twisty puzzle has an unusual shape, and can be turned on six different axes: the three axes going through the four-sided vertexes can be turned in increments of 90 degrees, and the three axes going through the diamond-shaped faces can be turned 180 degrees. I fiddled with this one a bit just to see how it turned, but I didn't spend any time trying to solve it.

**Kernel by Sam Cornwell**

The goal of this puzzle is to take it apart and re-assemble it. Unfortunately, I didn't get a chance to try this one, I'm not quite sure how I missed trying it. I saw a few people working on it, and it looked like it was fairly challenging but doable. I like the symmetry and appearance of this one.

**Knot for You by Mineyuki Uyematsu (Mine)**

This puzzle will disassemble into four pieces: two beads, a ring, and the string with walnuts on the end. I thought the walnuts were a nice touch, Mine could have have just used beads, but this gave it a different look from your standard disentanglement puzzle. I spent a good 20-30 minutes working on this one, and wasn't having much luck, but eventually I figured it out. These string disentanglements are tricky!

**Lost L by Kohfuh Satoh**

This puzzle looks like a puzzle I had seen before where the goal is to make the letter E, so I tried that trick and didn't have much luck. I came up with a rather silly solution, and when I looked on the back, that was what was written! I think there is probably a more elegant solution though, since it said the solution is not unique, but I'm not sure!

**Magic Domino by W.G.H. Strijbos**

This puzzle is a bit complicated to understand, but it is a cool idea. It works on the same "vanishing" principle as The Vanishing Leprechauns Puzzle, but with the added fun of a sliding puzzle. First, you take the eight light dominoes out and rearrange the pieces so you can fit the seven dark dominoes where the eight light dominoes were. (there are two panels that move, like the Leprechaun puzzle). Finally, take out the spacer and slide the 11 squares around until you can fit the 8 white dominoes in the holes and return the spacer to its original position.

Like I said, a bit complicated but a cool idea in theory. After appreciating it for a bit, I didn't spend any time solving this one, since presumably it is just a matter of matching up the correct top piece with the right bottom piece, and I figured that would take a while and not be particularly rewarding. Then it is just a matter of solving the sliding puzzle to get the pairs you identified matched up. Pretty neat!

**Moscow Ball by Dmitry Pevnitskiy and Sergey Grigoriev**

I really liked the look of this puzzle: the rounded shape is a really nice touch and I liked the colors of the woods. Fiddling with it briefly, you'll quickly realize it is a 4-piece coordinate motion puzzle. The motion is quite nice with the whole puzzle expanding outwards. I didn't find it particularly challenging to take apart or put back together, but it is still a fun and nice-looking puzzle.

**Pack Berlin by Abel Garcia**

This is another one that I unfortunately did not have the time to properly solve. I played around with it a bit, but only enough to appreciate the nice craftsmanship. The pieces were nice and smooth, and fit well in the box. I really liked the choice of wood used for the pieces!

The designer notes: "This puzzle was designed with three goals in mind: all pieces of the same thickness, unique solution, and difficult or impossible to solve using puzzle-solving computer software. The puzzle incorporates the 'missing area' principle into a 3-D box-packing puzzle."

**Puzzle Gift Box by Allen Lin**

I was quite curious about this one, since I couldn't identify who made it. It is a rather innocuous looking box, so it could be hiding any manner of surprises. I solved it in about 5-10 minutes, it is fairly tricky but uses some fairly common tricks in secret-opening puzzles, so I didn't find it all that interesting. Hopefully Allen will continue designing boxes, I look forward to seeing what else he comes up with!

This is another puzzle that I didn't really spend any time with. It has 68 pieces which is just mind-boggling! Of these pieces, you can select a subset that can be formed into either three small squares (simultaneously) or one large square. There are nine subsets with this property. The large squares can then be stacked to form a cube. Phew! That sounds like a lot of work! Here's a link to a paper with more information about the history of these dissections.

This is a cute little puzzle where the pieces spell out the word RAT, and you can also use them to construct a rat! As you may expect, since there aren't many pieces, this isn't particularly challenging. I solved it in only a minute or so. Still, a cute idea! It may be fun to do a series of these for children.

The goal of this puzzle is to assemble the four pieces inside the frame such that none of them sticks out. It is nicely crafted and I liked how all four pieces are identical. Unfortunately, I didn't get around to solving this one! I'll have to try building it out of LiveCubes at some point, since it looks like fun.

This is another design where the goal is to put the pieces in the box in such a way so they don't rattle around if you shake the box. I was able to figure out fairly quickly what the structure inside should look like, but I had a hell of a time actually constructing it! I must have spent a good 45 minutes on this one. I gradually built it up, and then it collapsed. This happened a bunch of times, but I was determined to solve it. Eventually I did get it! It was quite satisfying, so I took a picture, but I can't post it here since then you'll see the solution!

Despite spending a fair amount of time on it, I don't think I liked this puzzle much since it was more of a dexterity challenge than anything. Even when you got the structure together, I found that it was highly unstable. I think perhaps making it out of a different material would have helped, or making it larger (though it was already quite large). Also, the joints on the box were a bit spiky and poked my hand as I tried to put the pieces inside, so that wasn't so great as well. Still, an interesting geometric construction that I wouldn't have thought of!

The goal of this puzzle is to use the eight dark pieces to make an S inside the frame. I fiddled around with this one for a bit, but didn't have much luck. I have a tough time with these more abstract puzzles where you don't know quite what you're supposed to be doing. Eventually I gave up and looked at the solution, and it is pretty good! Perhaps I would have gotten it if I stuck with it a bit longer: it is tricky but not impossible.

This is an interesting variation on a twisty puzzle where the faces are held onto the core by magnets. You then use the two clear shells to rotate the pieces in a number of ways. I tried to play around with this one just to see how it worked, but unfortunately one of the shells had broken. It doesn't really work without the shells since the pieces fall apart in your hands. Oh well! It is a clever idea!

I was suspicious about this puzzle since usually a puzzle claiming to be simple is anything but! So I suspected that some amount of random fiddling would lead to the conclusion that the puzzle was impossible, but then there would be a sneaky trick to make it possible. All this speculation was for naught: it is actually just as it appears, a split ring puzzle with a notched cage. You just have to navigate a maze to get the ring to the exit position. I spent a minute or so on this one before figuring it out, it actually was pretty simple!

This is another interesting variation on the a sliding puzzle. Similar to Magic Domino, the goal is a bit complex: "Put the 15 pieces in the tray to construct the digits 1 through 9 in numerical order. Then slide the pieces to form a magic square (you must first determine how this magic square can be constructed)." I tried the first part, which is just to assemble the digits 1 through 9, and had a hell of a time doing that. The pieces are digits look pretty unusual, and each spans multiple tiles. Also, there is a black border around the puzzle which obscures the edges, so you can't even use the strategy of starting in a corner very effectively. Very tricky!

Ok, that's all for now! I should be able to wrap it up tomorrow, so stay tuned for the final installment!

**Quadratum Cubicum by Christian Blanvillain**

This is another puzzle that I didn't really spend any time with. It has 68 pieces which is just mind-boggling! Of these pieces, you can select a subset that can be formed into either three small squares (simultaneously) or one large square. There are nine subsets with this property. The large squares can then be stacked to form a cube. Phew! That sounds like a lot of work! Here's a link to a paper with more information about the history of these dissections.

**RAT by Kohno Ichiro**

This is a cute little puzzle where the pieces spell out the word RAT, and you can also use them to construct a rat! As you may expect, since there aren't many pieces, this isn't particularly challenging. I solved it in only a minute or so. Still, a cute idea! It may be fun to do a series of these for children.

**Ring Case by Osanori Yamamoto**

The goal of this puzzle is to assemble the four pieces inside the frame such that none of them sticks out. It is nicely crafted and I liked how all four pieces are identical. Unfortunately, I didn't get around to solving this one! I'll have to try building it out of LiveCubes at some point, since it looks like fun.

**riZidity by Bram Cohen**

This is another design where the goal is to put the pieces in the box in such a way so they don't rattle around if you shake the box. I was able to figure out fairly quickly what the structure inside should look like, but I had a hell of a time actually constructing it! I must have spent a good 45 minutes on this one. I gradually built it up, and then it collapsed. This happened a bunch of times, but I was determined to solve it. Eventually I did get it! It was quite satisfying, so I took a picture, but I can't post it here since then you'll see the solution!

Despite spending a fair amount of time on it, I don't think I liked this puzzle much since it was more of a dexterity challenge than anything. Even when you got the structure together, I found that it was highly unstable. I think perhaps making it out of a different material would have helped, or making it larger (though it was already quite large). Also, the joints on the box were a bit spiky and poked my hand as I tried to put the pieces inside, so that wasn't so great as well. Still, an interesting geometric construction that I wouldn't have thought of!

**S in Bloom by Gregory Benedetti**

The goal of this puzzle is to use the eight dark pieces to make an S inside the frame. I fiddled around with this one for a bit, but didn't have much luck. I have a tough time with these more abstract puzzles where you don't know quite what you're supposed to be doing. Eventually I gave up and looked at the solution, and it is pretty good! Perhaps I would have gotten it if I stuck with it a bit longer: it is tricky but not impossible.

**Shift Pole by Albert Gübeli**

This is an interesting variation on a twisty puzzle where the faces are held onto the core by magnets. You then use the two clear shells to rotate the pieces in a number of ways. I tried to play around with this one just to see how it worked, but unfortunately one of the shells had broken. It doesn't really work without the shells since the pieces fall apart in your hands. Oh well! It is a clever idea!

**Simple Solid Ring Maze by Yuta Akira**

I was suspicious about this puzzle since usually a puzzle claiming to be simple is anything but! So I suspected that some amount of random fiddling would lead to the conclusion that the puzzle was impossible, but then there would be a sneaky trick to make it possible. All this speculation was for naught: it is actually just as it appears, a split ring puzzle with a notched cage. You just have to navigate a maze to get the ring to the exit position. I spent a minute or so on this one before figuring it out, it actually was pretty simple!

**Sliding Put Together Puzzle by Ton Delsing**

This is another interesting variation on the a sliding puzzle. Similar to Magic Domino, the goal is a bit complex: "Put the 15 pieces in the tray to construct the digits 1 through 9 in numerical order. Then slide the pieces to form a magic square (you must first determine how this magic square can be constructed)." I tried the first part, which is just to assemble the digits 1 through 9, and had a hell of a time doing that. The pieces are digits look pretty unusual, and each spans multiple tiles. Also, there is a black border around the puzzle which obscures the edges, so you can't even use the strategy of starting in a corner very effectively. Very tricky!

Ok, that's all for now! I should be able to wrap it up tomorrow, so stay tuned for the final installment!

If you put the lid on the box for riZidity and hold it in with a rubber band or whatever then the internal structure suddenly becomes very stable, which was the whole goal of the design. There are lots of puzzles like that sold more as artwork than as puzzles, where for the most part you just attach the pieces together until it's done. I wanted to make one where there was a real puzzle component.

ReplyDeleteHi Brian,

ReplyDeleteYou can discover the history of the 9 disections used to buid the Quadratum Cubicum on this publication:

http://arxiv.org/abs/1012.0827

It also provides the solutions...

All the best,

Christian.

@Bram Cohen - I really liked the idea and look of your puzzle, 'riZidity'!! Is it for sale anywhere?

ReplyDeleteOh and I forgot to mention, great IPP blog series Brian! Anxious to read your next (and final instalment?)....:)

ReplyDeleteBrian, It's a most entertaining series of posts so far!

ReplyDelete- Chris Morgan

You can buy Bram's RiZidity on Pokoko:

ReplyDeletehttp://www.ponoko.com/make-your-own/toys/rizidity-6013

Ah, interesting Bram!

ReplyDeleteThanks for the link, Christian, I'll add it to the post.

Thanks John and Chris! I'm glad you're enjoying them :)