Chain Gang

Chain Gang is another puzzle sent to me by Puzzle Master to review. This puzzle was originally designed by Dick Hess (name "Outrageous Rings") and was adapted for Puzzle Master by Allan Stein, one of the owners of Puzzle Master. Dick Hess is a very prolific designer of wire puzzles that can be quite difficult. One of them, The Yak, took me about a year to solve, you can read about that here: My Puzzle Nemesis Vanquished!

This one wasn't quite as difficult, but still had me stumped for quite a while. It is nicely crafted out of sturdy wire, with a big heavy ring on one end. The object is to get the oval ring off.

If you look closely at the picture, you can see that it is sort of like a chain that passes through itself. Starting at the big ring at the top, it loops down through the middle of itself, then at the bottom it turns to the left and passes through its end. It goes back up on the left and turns right at a ring (where it passed through itself near the beginning), and on the right hand side it swoops around back down to the ring at the bottom, where the chain terminates.

It is a bit tricky to see what is going on in the metal version, but Marcus Gotz created a version that was made out of rope named Double Edged Thought which was part of his IPP29 exchange Six Serpentile Strings. I found that it was quite a bit easier to see what was going on here.

Still, I was pretty stumped. I carried this puzzle around in my pocket for about two weeks, working on it here and there. I drew a diagram of it on a sticky note, hoping that I would arrive at some inspiration by staring at it. Unfortunately, none of this did the trick. Unlike some puzzles where it takes a little while to figure out that you're at a dead end, I was having trouble making any sort of progress beyond the starting point.

Finally, this Thursday night I had both some free time as well as a firm resolve to solve this damn puzzle so I could write about it. I worked on it for about a half hour and felt like I was starting to make a bit of progress, but again I was stuck. I was a bit discouraged so I set it aside for a bit, hoping to return to it later. When my fiancée, Kellian, arrived home, I told her about the trouble that I was having with it and explained  the different things I had tried.

Then she made an interesting observation about the construction of the puzzle that I hadn't noticed before! Indeed, it was an unusual feature that must have been placed there for a reason, and I figured out the reason. This focused my search for a solution somewhat. About 15 minutes later, I had solved it! I think in all I must have spent at least 3-4 hours on it. What a relief to have it done!

The solution is quite tricky: even after I had solved it, I wasn't exactly sure of the mechanics of what was happening. I re-solved it a number of additional times and now feel like I have a better handle on it. It is definitely not something that I could have come up with just by staring at a picture if it.

George Bell was kind enough to send me a photo of Outrageous Rings, shown here. It looks like the main difference is that Chain Gang has the addition of a smaller diameter ring before the final ring in the chain (the silver one, not the gold one). Also, the two straight pieces at the bottom of the Outrageous Rings photo are of equal length in Chain gang.

Overall, I'd say that Chain Gang is a great puzzle. It looks darn near impossible at first, but if you keep at it you'll discover a clever solution. Another great design by Dick Hess! I think I might have preferred Marcus's rope version, since it is a bit easier to tell what is going on. The metal version gets quite confusing with all of the rings rattling around, though I guess that's part of the point. It is a matter of personal preference, I suppose.

Thanks again to Puzzle Master for making this review possible!

Rik's Egg Balance and Around the World

Rik's Egg Balance and Around the World are two more of the 2010 IPP Exchange puzzles I borrowed from George Bell. Rik's Egg Balanced was presented, designed, and made by Rik van Grol  at Buttonius Puzzles & Plastics. You probably know Rik from his publication Cubism for Fun, a booklet published three times a year with articles written about puzzles.

The goal of this puzzle is pretty classic: to get the egg to balance on its short end. This type of puzzle has been done a number of times and as Rob Stegmann notes, the U.S. Patent Office devotes an entire sub-class to "Balancing Ovoids" (ccl/273/154). This one is made out of plywood that has been laser cut and glued together.

Of course, you can't just stand it on its end by balancing it carefully. You need to first manipulate the puzzle in a certain way to get it to balance. You'll immediately notice that there are a few things rattling around in there. If you shake the hell out of it, you may end up with a ball bearing visible through the hole that the arrow points to (which goes all the way through the puzzle). It takes a bit more of a deliberate method in order to actually solve it though.

I think it took me about 5 minutes of rattling around before I solved it for the first time. What I didn't like about this one is that there wasn't an 'ah hah' moment, it was just some methodical manipulation until it worked. Perhaps there is a more clever way of solving it, but the way I found has only a moderate chance of success. Still, I can solve it in about a minute or two this way.

I tried this one out with my family to see how they found it, and most just rattled it around a bit before giving up. I think this type of puzzle is not as compelling as some other types because you don't really know what is going on. You have to make some educated guesses and go from there, which is how I figured it out.

Around the World is an assembly puzzle presented and designed by Kozy Kitajima. The illustrations on the pieces was done by Miwa Miwa.

This is another laser cut puzzle, but this one is made out of what appears to be fiberboard. The goal is to place the pieces so that the 8 pieces create a closed loop. Not all of them are shown in the photo.

Like a lot of puzzles of this type, I wasn't really sure where to start, so I just started messing around a bit hoping I would stumble upon the solution. However, when I got to the last few pieces I could see that it wasn't going to work out.

There is probably some logical way to figure this out, but I decided to try brute-forcing it by trying every possible combination of pieces. Fortunately, the pieces are numbered, so it was pretty easy to keep track of where I was. If you just look at all the possible permutations, there are 40,320, but since it is cyclical there are only 5,040 different distinct ways of arranging the pieces in a circle. This may seem like a lot, but sometimes you can tell that the first four pieces cannot produce a valid solution if there is no way to get back to the start.

I think I was about 1/7th of the way through the permutations in 30 minutes before I stumbled across a solution that worked. Phew! If that sounds like a lot of tedious work, it was! Assembly puzzles are not one of my favorite types, perhaps it is because I make them laborious by using techniques such as these. Any suggestions for a better approach?

Thanks again to George for loaning me all these puzzles! I've got about 6 left to write about, though two I haven't solved yet. I need to get cracking!

Plus Puzzle

Plus Puzzle is another one of the 2010 IPP Exchange puzzles I borrowed from George Bell. It was designed and presented by Edi Nagata.

One unique feature of this puzzle that you'll notice right off the bat is that it was made out of LiveCubes (puzzle building blocks) that have been glued together. I've previously written about LiveCubes here. Some folks may not like that it is constructed this way, but it didn't really bother me. I think that Edi actually is the inventor of LiveCubes, so it is not surprising that he used them for his exchange puzzle. Since they are glued together, I was a bit concerned that they would break easily, but it ended up being pretty sturdy.

The purpose of this puzzle is to change it from the shape shown above, to the shape shown on the left. There are little nubs that fit together when it has been solved. You can sort of see the green nub in the upper left corner of the cross above.

It consists of two identical interlocked pieces, and requires a number of rotational moves to solve it (around 6-8 moves, depending how you count). It doesn't come completely apart, though the design could probably be modified somewhat to enable this. If that was done, I think it would make a great addition to Hanayama's Cast Puzzle series.

I found it moderately challenging, it took me about 10 minutes to solve. I found one of the moves to be  unintuitive in a clever way, which I think is what makes this one challenging. There is different point that I found physically difficult to navigate even when I knew the solution. You need to have the pieces lined up just right to make it happen.

It is also a bit of a challenge to get it back to the start, though of course somewhat less so if you paid attention to what you were doing in the first place. I got stuck briefly near the end, but eventually figured it out.

Overall, a nice puzzle! I like the fact that a puzzle with rotational moves like this can't be solved by a computer easily. I guess the only slight downside is the construction, but I didn't mind that much. You would certainly have to be less careful with it than if it was made out of nicely finished exotic wood! I do think it makes it a bit less compelling to play with though: I brought it to Thanksgiving at my family's house, and I think only one person attempted it (unsucessfully). Also, the 'solved' state isn't quite as satisfying as having the puzzle come apart, and it was a bit difficult to explain to a non-puzzler.

Still, it is a good puzzle that I enjoyed solving. Thanks to George for loaning it to me!

The Big 30

The Big 30 is another puzzle sent to me by Puzzle Master to review. This puzzle was designed by Allan Stein and presented as Allan's exchange puzzle at IPP 30, hence the shape. Cute, eh? I had seen this puzzle during the exchange, but hadn't gotten a chance to try it, so I was interested to see how it was.

The goal is to remove the zero from the three. As you can see in the photo, the zero is just looped around the three, with the gold chain and ball keeping it from being removed.

After a few moments of playing with this one, I had a pretty good idea of what needed to be done. Of course, sometimes knowing what needs to be done is easy and actually doing it is tough! In this case however, I was able to figure it out pretty quickly. I think it took me less than a minute.

I was interested to see how difficult other non-puzzlers would find it, and was quite surprised to find that they actually had a good deal of difficulty with it. Watching folks try to solve this one was a bit like watching somebody try to push a "pull" door, it seemed so obvious to me, but clearly it was not. Most gave up before solving it after playing around with it for a 5-10 minutes. A particular part of the solution is a bit un-intuitive, so I think that is where folks were getting hung up. A good puzzle takes advantage of these mental blocks to stump you!

The folks at Puzzle Master rate this as a 6 out of 10 difficulty, and I am inclined to agree, though perhaps it should be a 7. I think it is about the same difficulty as the last puzzle I wrote about, Panic Attack, if not slightly harder. Still, my sample size is a bit small so who knows! I think it really depends how much experience you have with this type of puzzle.

Overall, a nice little puzzle that is well designed and crafted. It was a bit too easy for my taste, but I did enjoy showing it to other folks! Thanks again to the folks at Puzzle Master for sending it to me!

Panic Attack

Panic Attack is another puzzle that I received from Puzzle Master to review. This puzzle is designed by Kirill Grebnev and manufactured by PuzzleMaster. Kirill has also designed Harmony, which won the Puzzler's Award and Jury First Prize at IPP30 in 2010, and Forest Puzzle which won an honorable mention at IPP27 in 2007.

Like all of their wire puzzles, the quality is great. The wire is a thick enough guage to be sturdy, but no so much that it is heavy. It has a nice shine to it as well.

The objective is pretty simple: remove the yellow loop from the heart. I like puzzles that appear simple like this one: only two pieces! It reminded me a bit of Iwahiro's Dinghy, where you are also removing a flexible loop from a wire structure.

At first, it looks fairly impossible, which is always a good thing for a puzzle like this. However, there aren't very many dead ends, which made it pretty easy. I think I solved in about a minute or so. I brought it to a family gathering and some people had a much easier time with it than others. Most had the right idea, but it must be executed in the correct way. I think this is a bit easier than an 8/10, maybe closer to a 6/10, but it really depends.

As for drawbacks, the only thing I can think of is that rope is just a hair too short for my taste, but it probably varies a bit and some may actually prefer it this way. Overall, a fun puzzle that has a nice simplicity. A great design by Kirill Grebnev! Thanks again to Puzzle Master for sending it to me to review!

Meffert's Pyraminx

I'm not typically a twisty puzzle fan, but recently Puzzle Master sent me some puzzles to review, and Pyraminx was one of them! This was actually the first puzzle designed and produced by Uwe Meffert way back in the 1970's. The Pyraminx has so far sold over 90 million copies world wide, making it the second most popular puzzle in the world! 

I had seen photos of it before, but I wasn't quite sure how it rotated, so I was interested to give it a try. It is actually one of the easier twisty puzzles out there, which also appealed to me since I'm not particularly good at them.

Each of the four corners rotates independently, so those are quite simple to position. If you go down one level from a corner, it can also rotate along that axis, which consists of the corner, three edge pieces, and three middle pieces. You can't rotate a single edge, which I found myself trying to do a few times before I got the hang of how it worked.

It turns quite nicely, and has spring loaded ball bearings that lock it into place when you complete a turn. This gives it a nice clicking noise as you solve it. I was also impressed by the weight of the puzzle, which gave it a nice feel.

Since it wasn't supposed to be too tricky, I scrambled this one right away and gave it a try. After about 5-10 minutes I was able to get all but two pieces in place, but those last two vexed me. In my attempt to get them positioned properly, I managed to screw up the rest of the puzzle, so I essentially had to start over.

At first I was just trying to get one face to be all the same color, but just randomly twisting with that purpose in mind wasn't doing me much good. Eventually, I figured out a move that would bring a piece into the correct position. Interestingly, this is quite similar to a move that I learned to use on 3x3x3 cubes, but it is pretty intuitive.

Again, I got to the position where only two pieces were off, but this time in my attempt to get things in the right spot, it all came together! It was a nice little surprise, but I wasn't quite sure how I did it. In total, it took about 15-20 minutes.

Not content with not knowing how I finished it, I decided to scramble it and try again. This time, I had a more methodical approach, and was able to solve it in several minutes. It really isn't too hard because there are only six pieces that are a challenge to position: the six edge pieces. The others are either quite easy to fix, since you can just twist the corners to match up to their adjacent piece, which doesn't move when you rotate the puzzle.

I can't really think of a negative aspect of Pyraminx, it is a lot of fun! It is a good one to try if you're just getting your feet wet with twisty puzzles. If you're good at them, you may find this to be too easy, but you'll probably want it in your collection anyways. Thanks to Puzzle Master for sending me this puzzle to review!

Six Piece Cross and Icosahedron

I recently borrowed a number 2010 Puzzle Exchange puzzles from George Bell, one of was Six Piece Cross by Vaclav Obsivac (a.k.a. Vinco). It was presented by Patrick Major in the puzzle exchange at IPP 30. I don't see it on Vinco's website, but you can purchase it at Puzzle Master if you are interested.

Vinco makes some interesting puzzles, many of which operate on similar principals but have different appearances. This one has a similar operation to his Flattrick puzzle, though the appearance and mechanism are quite different.

There are six pieces, like the one shown here, that all slide together at the same time (coordinate motion) to create the shape shown above. It seems fairly straightforward, but in practice it is pretty challenging to get the pieces lined up just right to slide together.

I had done a similar puzzle before, so it only took a minute or so for me to solve, but it is definitely not easy. My girlfriend tried it out for a few minutes, and it drove her fairly batty: frequently you get very close to finishing, but the whole thing falls apart in your hands.

As with all of Vinco's work, the craftsmanship is nice with perfect fit. It has a natural finish, and is constructed out of walnut and plum, though Vinco frequently uses different woods for the same puzzle.

Overall, a solid puzzle that I enjoyed. I think the one downside to this one (and this type of puzzle in general) is that the solution is a bit fiddly. It does take a fair amount of dexterity to solve it, but it is quite satisfying when the last piece pops into place and the whole thing slides together.

Another Vinco puzzle that George loaned me is called Icosahedron. This was actually Vinco's own exchange present for IPP 30.

It is a bit hard to see in the picture due to the wood grain, but it is an icosahedron as you would expect from the name. This particular one is made out of a nice dark wood, though there were other versions available.

Since he has been doing a lot of coordinate motion puzzles recently, I expected this to be a coordinate motion puzzle as well. I had fiddled with it a bit at IPP, but didn't have any luck, so I was glad that I had the opportunity to try it again.

After a minute or two of fiddling, I was able to get it to come apart. It actually consists of four pieces, though there is no coordinate motion. I don't think most will find it particularly challenging. My girlfriend was able to get it apart in a few minutes, though she had trouble getting it back together. Getting it back together is tricky, because things need to be lined up in a way you may not expect.

As a puzzle, this one didn't interest me as much. However, the craftsmanship is superb: the pieces fit together just right. This puzzle is quite a bit smaller than the previous one. It is a bit more than an inch tall, I think. It has a smoother finish, which may be a property of the wood used. Overall, a nice little puzzle.

Thanks to George Bell for loaning me these puzzles!

Cast Rattle

I had actually tried Hanayama's Cast Rattle about three months ago during July, since it was an entry into this year's puzzle design competition in which it won an honorable mention. I had only spent about ten minutes or so on it at the time, since I figured it would be available soon and I wanted to spend my time at the competition trying out puzzles that I wouldn't have the chance to try again. I just had the chance to try it out again, courtesy of Puzzle Master!

It is an interesting design by Bram Cohen that consists of four pieces that rattle around, hence the name, but stubbornly refuse to come apart. The pieces appeared identical, and it is pretty obvious that there is no hidden mechanism, so it is a bit puzzling what keeps them from coming apart.

The finish on this puzzle is nice and shiny and  it has a nice weight in your hand, as is the case with most of Hanayama's Cast series of puzzles. The fit is prefect, with no force necessary but no unnecessary slop either in the solution. That said, it does rattle around quite freely and somewhat lacks the elegant and stable resting position of something like Cast Vortex, the first puzzle I got in this series. This is really the only downside to this puzzle for me, but there's not much that could be done about it.

I started out just fiddling around with it a for a few minutes like I had done at IPP previously, and similarly didn't end up having any luck. Clearly just fiddling with it idly wasn't doing the trick, so I needed to take a more logical approach. Depending on how you slide the pieces, you can see every part of them, so I was able to take a logical approach that ended up leading me to the solution. This was quite satisfying, since there was a nice "Ah hah!" moment when I figured out what I had to do, and after a minute or so I was able to execute the solution correctly. In total, I think it took me about 10 minutes. It only took me a minute or two to get back together since I had a pretty good understanding of what I had done.

I think this would be an appealing puzzle to hand to somebody, because they can get it to move around a lot, which feels like they're making some kind of progress. However, you really have to stop and think about it to find the solution. I tried shaking the hell out of it, and that didn't work for this one, which is always a good thing.

In terms of difficulty, I would agree with Hanyama's rating of 4 out of 6, it of similar difficulty to the others with that rating such as Cast Baroq. I think most will be able to figure it out within 20-30 minutes, though I know a pretty smart fellow who spent an hour on it! It just depends when the inspiration strikes you, I think.

Overall, Cast Rattle is a solid puzzle that has a beautiful simplicity to it and a clever solution. Definitely worth picking up if you're into this type of puzzle! Thanks to PuzzleMaster for sending me a copy to review!

Note: I've recently set up an affiliate arrangement with PuzzleMaster so I get a small percentage of the sale price if you buy puzzles from them using the links I provide. They're also sending me some free puzzles to review. Of course, I honor your trust and will do my best to keep all reviews as objective as possible and continue to give you both positives and negatives for every puzzle. Thanks for reading!

Newton's Egg by Stephen Chin

This puzzle was Stephen Chin's exchange puzzle at IPP30 in Japan. I had seen photos of Stephen's work before, but this was the first that I have had the pleasure of trying.

The goal is to open the egg, and the hint is that it is based on Newton's three laws of motion. This particular copy is made out of Huon Pine, which gives it a nice aroma. I was intrigued by the hint and decided to buy a copy.

When I got it, it arrived it a plastic tube and was wrapped in a kid's sock. It also included a tippe top made out of colored pencils that had been glued together and turned on a lathe! This is one of Stephen's 'signature' techniques. It also included the captured ring stand you seen in the photo on the right. The ring can't come off the stand because the diameter is too small, so it is sort of an impossible object. Of course, he achieves this by carving both the stand and the ring out of a single piece of wood. Stephen is a master of the lathe!

It is quite nicely crafted, with a smooth finish. At first, it looks completely impenetrable. I had no luck just trying to take it apart, so I figured there must be a locking mechanism of some sort. I immediately noticed that there is a rather pronounced rattling when I shook it, so I thought it might have some kind of gravity mechanism.

When I actually figured it out about 10-15 minutes later, I was quite surprised at the simplicy and cleverness of the mechanism! It is simple enough that I would have thought it had been done before, but I'd never seen anything like it. Additionally, it could not have been possible if it weren't for Stephen's excellent craftsmanship. It is a fun one to open, I find myself going back to it now and then just for kicks. Once you know the trick, it isn't hard to do, but folks could struggle with this for a little while their first time.

Overall, this is a great puzzle and I'm glad that I got it. I look forward to seeing what Stephen will come up with next year!

TenPlate Puzzle

As I mentioned in the Part 5 of my series of posts about the 2010 Rochester Puzzle Picnic, Jeff Aurand gave a talk about writing a computer program to solve all TenPlate puzzles. At the end of his talk, he had a drawing for a copy of this puzzle, and I won one!

I hadn't had a chance to work on it until now, and I was curious to see how difficult it would be to solve manually. In this photo by Jeff you can see it in one of its solved positions. There are a number of solutions to it, though Jeff would have remind me how many.

The puzzle consists of ten flat pieces. There are five notches, each of which can either be tall or short. Each piece has a different combination of notches. They can be arranged as shown above to create a cube.

This puzzle was designed and made by Jean-Claude Constantin and was Luc De Smet's exchange puzzle at IPP28 in Prague. It is nicely laser cut with what appears to be a veneer of some sort, which gives it a pretty good finish for a laser cut puzzle.

I worked on it for about 20 minutes before dinner one night. My strategy was to just guess at the location of a particular piece, and try to find a combination of the other pieces that would work. When a particular arrangement wouldn't work, I'd rearrange a piece or two in hopes of remedying the issue without screwing something else up. I hoped that I had picked a location that would work for that first piece! Unfortunately I ran out of time that night and had to return to it the next day.

The next day I had a bit more time, and again continued down the same path that I started the previous day. After about 30 more minutes, I was cursing the fact that the last piece wasn't going to fit yet again. However, upon closer inspection, I noticed that it would! I was quite satisfied as the last piece slid into place.

The one thing that bugged me about this puzzle was the difficulty in lining up the pieces. Since they are fairly long, it is hard to get them quite lined up so that the grooves slide together. On more than one occasion, I would be lifting the puzzle up and wiggling pieces trying to figure out why it wouldn't slide together, only to have another piece fall out of place.

Also, it is a bit of a dexterity problem to try to get a piece out of the bottom layer without everything falling apart. I ended up just taking off most of the top layer before messing with the bottom layer, since that was usually safer.

A similar puzzle that avoids these issues is StabPuzzle by Logika Spiele. Logically it is the same idea, but physically the pieces are different. This particular puzzle is a bit simpler since it only has 8 pieces rather than 10, but the same idea could be adapted to this 10-piece puzzle. While it may be easier to manipulate, it doesn't look quite as cool as TenPlate or stay together as well.

Rob Stegmann's website has quite a bit of information on this group of puzzles, which he calls Crossed Sticks puzzles. He even wrote a solver that could solve variations of this puzzle up to 5x5. Pretty cool!

Overall, a nice little puzzle. I would say that it is fairly difficult, you'll need to be either lucky or patient when solving this one. Thanks again to Jeff for giving it to me!