Dragon Cube is a fascinating little puzzle from the folks over at Gotta Solve It. Invented by their chief mechanical puzzle engineer, Doug Engel, the Dragon Cube is able to transform itself is several different shapes. This was first introduced in 2000 as an exchange puzzle at the 20th IPP, then called Perfect Ring of Eight.

The puzzle is built from wood and painted with eight different colors, producing a very nice visual effect. Although I prefer wooden puzzles, in this particular case I think plastic would have been much more appropriate, since you're dealing with colors. Paint and wood don't always go well together, because you're more prone to imperfections. Nevertheless, the coloring was very well done and you can hardly notice any spots or blemishes. The cube is also quite small, with 5cm in diameter (2").

Consisting of eight different dovetail pieces, your first task is to take the cube apart. You can easily do this by removing the pieces in pairs, instead of trying to separate them one by one. Once you have all eight pieces removed, there's a total of 14 shapes you can try to assemble them into.  They vary in terms of difficulty, but overall they aren't overly challenging to solve.

Before attempting to solve any of the other shapes, I first tried to reassemble it back into its cube form. This was the toughest of the challenges, also because it was the first time I was solving it. It must have took me about 30 minutes to have the cube shape again. After that, the other shapes weren't that difficult to solve, and I managed to solve them within 10 minutes each. You can see three other shapes other than the cube in the photos below.

Closing Comments:

The Dragon Cube is a total different concept from what I'm used to see in puzzles. It's quite refreshing to see such originality and it's rather fun to solve. The 14 shapes will surely keep you busy for a while, if you can solve the cube first, that is...

Availability: You can get a copy of the Dragon Cube at PuzzleMaster for $20 CAD.

EZ Atom by Doug Engel is a stunning looking puzzle, produced by PuzzleMaster in Canada. Doug is known for his elegant and exquisite puzzle designs, mostly in metal, as you can see here. I have a few of those in my collection.

The EZ Atom is comprised by three metal pieces coated in bronze, silver and gold, plus a blue marble, which is trapped in the middle. Looking like an impossible task at first, the object is to take all the pieces apart and free the marble.

The design principle reminds of Constantin's Sputnik Ball, also reviewed a couple of weeks ago (see this post), where you also have a trapped marble in the middle that looks impossible to get out. While in the Sputnik Ball there was a sort of trick to free the marble, the EZ Atom is not that "tricky" and the solution is as simple as using a bit of force... Actually, I want to emphasize the force part, because it does require a good amount of pressure to release the pieces just enough to disassemble it.

This is a puzzle that is rated by PuzzleMaster as a difficulty level 6/10, but I have to disagree with this one. Should be more like a 7 or even an 8. Curiously enough its difficulty level is described as "tricky", although there's no trick involved.

When you first try to take it apart, the puzzle pieces don't have that much room to move, so you're made to believe that it must have another way to be solved other than brute force. It took me about half an hour to figure out that applying pressure on the pieces was the only way. I'm not sure if my copy was tighter than usual or if this is standard for the design, but as I see it, not everyone will assume, at least not at first, that the puzzle does needs some force to be solved. This is why I think the puzzle is actually harder than it's advertised.

Reassembly is also a bit challenging, especially if you didn't pay much attention to the order that the pieces were removed. You should be able to figure it out soon enough though, because the three pieces are all dissimilar and have different openings. Hint: the bronze piece is the first one out and last in.

Solution: If you get stuck, you can download a solution guide here.

Closing Comments:

Despite getting harder than I was expecting, the EZ Atom is a really nice puzzle. If you like a challenge, you're in for a treat. As well as being a great-looking puzzle, it also offers some frustrating moments. Can't ask for more, now can you?

Availability: You can get a copy of the EZ Atom at PuzzleMaster for $16 CAD.

The first time I saw the Trinity Infinity puzzle, I was impressed by its design. The way the pieces were interlocked, it sort of reminded of the Cast Coaster and Oskar's Lucky Clover.

The design is an original by Doug Engel, manufactured by Bits and Pieces and measures 11,5cm x 6,5cm (4,53" x 2,56"). The puzzle is in the shape of the mathematical symbol for infinity, and is comprised of three pieces, with two of them being identical. A nice finishing touch is the tripled colored pieces, which look very nice: one golden, another one silver and the other graphite, make a nice contrast. However, the coating quality on the puzzle's pieces leaves much to be desired. There were noticeable parts where the coating was chipped off and others had a few small dents here and there. Nothing that prevents you from having a full satisfying solving experience, but appearance-wise it does look a little bad and it's beyond understandable. The small price on the puzzle is not an excuse either, because about the same price Hanayama Cast Puzzles are very high quality when it comes to coating. I do have a Cast Marble puzzle that looks awful with bubbles in the coating finish, but that was an exception to the rule.

Now, regarding the puzzle itself... The goal is to separate the three pieces from each other and then reassemble them into their original infinity design. The first part, which is to unlock the pieces, was very easy. Two of the pieces have a gap that is large enough to pass through the piece's thickness and the middle one, the golden, is closed. With very little effort, the pieces were almost separated by themselves. The second part of the task, though, was a bit more tricky. PuzzleMaster rates it as a 6/10, and this time, at least for me, it was more like a 7/10. Probably took me around 15 to 20 minutes to finally figure out their interlocking secret. The key is having the middle piece and one of the other pieces already in their finished state, so that the third one is put in place much more easily. Apparently, PuzzleMaster doesn't have a solution for this one, but if you need any help to solve yours, let me know and I can send you a scan of the solution sheet.

(Click to Enlarge)

Despite the quality of the Trinity Infinity not being the best around, the design and its challenge, especially the second part, is worth it. It's complexity is not something that will scare away casual puzzlers, but if you're experienced with disentanglement puzzles, maybe this one isn't for you.

The Trinity Infinity can be found at PuzzleMaster for $9.99 CAD

The Secrets of the Heart is a puzzle from Bits and Pieces, designed by Doug Engel and sold by PuzzleMaster.

The puzzle is made by five nickel plates in the shape of a heart and a gold ring. It's quite heavy for its size, but expectable due to the number of metal plates used in the puzzle. At first glance it may look like the goal is to remove the ring, but you actually need to unlock a sliding arm from one side of a puzzle. When you do this, you'll discover that inside is a small compartment to enclose something special.

As far as difficulty goes, the Secrets of the Heart is a fairly easy puzzle to solve. It's rated by PuzzleMaster as 5 out of 10, so the easiest you can get at PuzzleMaster. To open it, you'll just need a couple of minutes to inspect the puzzle: the ring functions as a locking system and you just need to rotate it from one side to the other, in order to allow the arm to slide off the puzzle. Returning the arm to its position is even easier to do, because you already know the secret to open it, so you just need to maneuver the ring appropriately to close the heart again.

As an experienced puzzler, you won't find the Secrets of the Heart remotely challenging, but it's definitely a must for a collector, especially if you're into metal puzzles. It's very different from what you're used to see in puzzles and on top of that, a simple and beautiful design.

The Secrets of the Heart is available at PuzzleMaster for CAD $14.99.

Yin & Yang by Doug Engel is an interlocking puzzle available at SeriousShops.com. It was entered at the 2004 24th IPP Design Competition, at the time by the name of Double Monad. This ancient Chinese symbol, that represents opposite interconnected forces in harmony, is an inspiration even in puzzle building, which at first glance, it doesn't remotely look like a puzzle.

Like every other puzzle like this, the goal is to take it apart. There's four interlocking nickel plated pieces that together make two overlapped Yin & Yang symbols. When you take it apart, your new and probably harder task is to return it to the original form. 

Since the pieces aren't very tight together, you'll be able to move them easily. It doesn't mean that it's that easy to solve though, because you still have to figure out how the pieces are joined together and which one will be released first. For a first timer, it may take a while to solve it, but if you're used to this type of puzzles it shouldn't take you more than 10 minutes.

The presentation of the puzzle is very pleasing, with its elegant and charming design, which was what got my attention in the first place. It's a simple, but beautiful concept and looks great on a desk...

The Yin & Yang is currently being sold in some European puzzle stores between €25 and €30 (~$32-$39 USD). That's why I was so impressed to see it at $13.95 in SeriousPuzzles.com, so get it while you can.