About a year ago, I reviewed the Hanayama Cast Key, which was one of their first three Cast Puzzles released in 1983. A few years ago, in April 2006, Hanayama released an updated version of this puzzle designed by Otake & Wong, the Cast Key II with a different look, but maintaining the classic appearance.

There are a couple of differences between the two versions, although the main concept of the puzzle remains the same. In other words, if you solved the original Cast Key, then the Key II is pretty much the same, except the solution is less obvious. The first noticeable difference, besides the design, is the metal alloy used in the two puzzles: the first looked like it was made in brass, and judging by the smell it leaves in your hands, it must be; the second has a more clean, polished and smoother finish with a silver coating. Another difference between the two is their size, as the Key II is about 1 and 1/2 times the size of the original.

If you've never solved the first Cast Key, the goal is simple: separate the two entangled keys and then, return them to their original state. Since both puzzles are basically solved in the same way, one wonders why the Cast Key is rated by Hanayama as 1/6, while the Key II is rated as 2/6 - I like how Hanayama uses the design of a die to represent the level of difficulty - If you have both puzzles and carefully analyze the two, it's easy to understand why... The Cast Key had these grooves that were marked along one of the keys, giving away part of the solution, but the Key II succeeds very well in hiding these subtle features much better, which adds a little more complexity for a casual puzzler, hence the difficulty 2/6.

Giving the fact that I have solved the first Cast Key in over a year, I completely forgot the steps required to untangle the new keys. In fact, I didn't mind that, because I got to enjoy even more solving the puzzle again, although I was still able to solve it within 10 minutes.

The solution, although not so straightforward as the first one, is still quite simple. Looking at the puzzle, it's clear that the key with the gap in the blade is the one that should be freed. A couple of turns around the two small knobs in the main key is enough to get it near the bow. Another couple of twists and turns around the bow and the key is finally freed. Getting it back to its original state shouldn't be any problem, even easier, actually.

(Click to Enlarge)

Closing Comments:

Back when I got the first Cast Key, it was one of my favorite Hanayama puzzles, because of this mystic and mystery feeling they give out. Now, I like the Key II even more. Definitely one of the best looking Cast Puzzle.

I am just recently a proud owner of the entire Cast collection and I can now fulfill a goal I hoped for when I started to collect them, which is to review them all. I expect to achieve this by the end of the year, although by that time, Hanayama should have a couple more out there, since they release about four new design each year...

Availability: The Cast Key II came from Sloyd and it's available for about €10. For all the other Cast Puzzles, check out their Hanayama Cast page here.

A little bit about Sloyd: This is a Finnish puzzle store, in business since 1989, and has a wide variety of mechanical puzzles and games. Browsing some of their inventory feels like a wonderland for any puzzle collector, as they have several puzzles that are very difficult to find anywhere else, like some from IPP Design Competition or from designers around the world, like Vesa Timonen or William Strijbos.

Note: This review marks the reaching of 100.000 page views of my blog, since May 2010. With a growing average of about 400 page views a day, and soon reaching the 200th review, I couldn't be happier by sharing my puzzling experiences with this wonderful community. Thank you to all my readers and please, look forward to what's next. There's always great puzzles out there to talk about... ;)

Links:

Hanayama Cast (in English) - Very useful website in English, with plenty of information on all things Cast.

Hanayama's Factory Visit (Many thanks to Roxanne Wong for sharing these pictures)

Ziggurat is a very nice exclusive puzzle sold at Puzzle Crafthouse and was designed by Mike Czerwinski. The puzzle is based on the shape of an ancient Mesopotamian temple with a flat top and four sloping sides.

The Ziggurat puzzle is entirely made of wood, pieces and tray, and measures about 15 square centimeters (6"). There are nine dissimilar pieces, each with a total of four to nine links distributed on its four sides. The object of the puzzle is to link all towers in a 3x3 square so that they're all connected by at least one link to each adjacent tower.

(Click to Enlarge)

The design of the puzzle is very well done and quite original. It's hard to imagine any other similar puzzles that have this unusual shaped pieces. One of the things I like most about the puzzle is that it has multiple levels of difficulty. I have to say that when I first tried it, I thought it had only one level, although I was rather suspicious when I solved the puzzle within 10 minutes. Sure, I could have been lucky the first time, but when I solved it a second time with approximately the same amount of time, it was too good to be true.

After I read the description, I discovered that indeed, it had three difficulty levels, and the two solutions I had just found were only a fraction of the 5.130 possible ones for the 1st level. Note that in order to solve level 1, you only need to have at least one link connecting all adjacent towers. The outer links are not important for the solution. Below is a picture of a level 1 solution.

(Click to Enlarge)

A couple of minutes later, I recovered from the disappointment and started to rearrange the piece layout to see if I'd find one of the possible 2.704 solutions for level two. It didn't take long either, and it probably took another 10 minutes or so. The good thing was that it wasn't necessary to remove all pieces from the tray, so a few piece swaps and it was solved. In level two, you now need to have at least two link sections connecting each adjacent tower. You can see below one of the level 2 solutions.

(Click to Enlarge)

The fun part, or grueling part, depending on your mood, is when you attempt to solve a level three solution... And to complicate things worse, there won't be thousands of solutions to find, but only a mere two. Here, you have to link all adjacent towers with three links. Given the complexity of the piece arrangement needed to accomplish this, it's no wonder that Puzzle Crafthouse has it among their highest rated puzzles, at 5+. In case you're wondering... No, I haven't solved this level yet. I did tried for about an hour, but gave up for now. I'm quite happy with the solutions I found and it won't be in the unsolved category. Thank you Mike, for the multiple levels of difficulty, otherwise this would've been a whole different story.

The Ziggurat is solely available at Puzzle Crafthouse for about $23 USD.

Closing Comments:

The Ziggurat by Mike Czerwinski is a brilliant concept with everything a good puzzle should have. The multiple levels of difficulty make it accessible to any puzzler, casual or experienced, and with more solutions than you will ever find, it's great to have around for a dull moment. Highly recommended for a packing puzzle fan.

Today, I have chosen to review another great design by Jean Claude Constantin. If you read my blog regularly, then you know I'm a big fan of his puzzles and I'm yet to find one that I don't like. As of now, I have about 30 of his creations and from what I gathered, this number doesn't account for more than 20% of all his designs. That says a lot about the sheer variety of puzzle ideas he came up with all these years.

The puzzle I have is called Nifty Fifty, and for those who do not know the meaning of this term, check out this page, as the design is reminiscent of a stock market chart, seen by the shape of the pieces as well as the horizontal and vertical lines engraved inside the tray. Measuring about 14.5 x 7.5cm (5.7" x 3"), this very original Packing Puzzle has only four laser-cut pieces, each with a different type of wood, and although similar in shape, they all have a different layout. Your task to succeed in the "stock market" is to get all four "lines" to fit inside the "chart". Easy, right?

The inner edges of the tray also have the same shape as the pieces, except they don't match exactly the outline on any of them. This is also true for the pieces themselves, because you'll only get partial matches between them. The rest of the space in the tray is wasted space. The trick is to arrange the pieces in such a way that you waste the minimum space possible. 

The Nifty Fifty is rated by PuzzleMaster as an 8/10 and, for what it's worth, it may as well been a 9/10, because I lost count to the number of times I've tried to solve this until this week, when I finally succeeded. Contrary to what it looks like at first sight, the puzzle is deceptively hard. Despite the unusual irregular shape of the pieces, each one has only four possible orientations, and even counting with a few adjustments inside the tray for every orientation, the total number of possible arrangements is not that high (a few hundred, maybe).

So why is it so damn hard to solve? - Well, unless you follow a strict systematic approach by writing down every arrangement you've already tried - and believe me, that's also quite exhausting - you're bound to lose track of what you've done and repeat many of your moves. My strategy is just to write down each piece you've tried first, followed by the second, and so forth... That way, you can keep track of what has and hasn't been tried. I'm not sure how many solutions are there for this puzzle, but judging by the nature of the pieces and the time it took to solve, I'd say it must be one or two, at the very most. To see the solution (only as a last resort), check out this link.

Closing Comments:

The Nifty Fifty is one of those puzzles that's simple enough for anyone to try their luck, but few will be able to solve it. The concept is rather original with the stock market theme, and also, design and quality-wise, the puzzle is superb, but that's what we've come to expect from a Constantin's design. A must-have for any packing enthusiast.

Availability: The Nifty Fifty is available at PuzzleMaster for $17 USD. There's another puzzle available, also by Constantin, called Aladin, which uses the same type of pieces, but with a different design. Honestly, I liked the Nifty Fifty idea better, because of the striking resemblance of a stock market chart.

Qboid is an interesting wooden puzzle invented in the United Kingdom by Colin James in 2008 and manufactured at Lakeland Puzzles. A year later, the inventor entered the puzzle at the 29th International Puzzle Party (IPP) Design Competition.

The Qboid has an astounding number of challenges (10.000+) divided in four levels, allowing you to build alphanumeric characters and other types of patterns. The puzzle is presented in a transparent plastic container, and inside are 12 wooden blocks with each one having its six faces covered with pattern stickers. I liked the contrasting colors with black stickers and orange segments. Each sticker and can have one of five possible configurations: four segments and one blank.

(Click to Enlarge) - Abstract Pattern

From the 12 blocks, each measuring about 3cm (1.2"), it's possible to stack them in one, two, three or four alphanumeric combinations. There are a few types of possible challenges for you to try, be it a number from 0 to 9, a letter, a word (e.g. DOG), an Hexadecimal number (e.g. 3E) or even symbols, like H2O.

Level 1 - Easy

(Click to Enlarge) - Level 1: A1

The first level only requires to make a character with six cubes and then to make another with the remaining 6. These are the easiest challenges to accomplish and the ideal for you to start getting used to the puzzle dynamic.

Level 2 - Medium

(Click to Enlarge) - Level 2: 83

The second level of challenges are a bit harder and aren't possible to solve in an horizontal plane, since you're gonna need to stack the blocks in a 45º angle. For these, you need only nine blocks to get a two character combination. The key here is to combine the middle three blocks to form the right part of the left character and the left part of the right character. Only one face of the blocks is needed for the two edges. Note that it's not always possible to get a blank sticker showing on the top of the blocks. For the challenges, what matters is showing the correct segments on the front faces. The top and back faces of the blocks aren't important. All numbers from 00 to 99 are possible.

Level 3 - Hard

To complicate things a bit more, the third level challenges now require the 12 blocks to be solved. In this level you need to get a character showing on three sides of the Qboid. The fourth side is not important and can have any segment, as well as the top side. Contrary to the level two challenges, where you had to combine segments from the middle blocks, now you need to combine segments from two corners of the puzzle in order to form the three characters.

You can form numbers from 000 to 999 and several three letter combinations, but there's a catch: Not all number or letter combinations are possible, so it's up to you to find out which ones are possible. It can be a bit frustrating trying to solve a particular challenge, only to find out that there's no solution. Don't give up at the first hurdle though, because with a few blocks swaps it's possible to still find a solution.

Level 4 - Expert

Finally, we get to the fourth level. Now, this one is really tough. Here, you need to make a four character combination with one character showing on each of the four sides. Besides the number challenges, you can also try to solve four letter words or four character Hexadecimal numbers (LEAF and 32Ad are two possibilities). What makes this level very hard is finding the correct corner combinations on all four sides, because you're using all blocks. The third level also uses the 12 blocks, except the fourth side is not relevant and can have any segment showing. It has been proven that there are, at least, 100+ possible numbers from 0000 to 9999 (e.g. 0972, 1594, 3012).

Closing Comments:

With an overwhelming number of challenges, from numbers to words or even symbols and abstract patterns, the Qboid is an extremely versatile puzzle with plenty to offer. Regardless of the variety, the concept doesn't change, so after a while, the puzzle can become a bit repetitive when trying the same type of challenges over and over again.

The quality of the wood in the blocks isn't very good though, and the choice of having stickers was not a great one. Painting over the wood would've probably be a better choice, aesthetically. Using plastic for the blocks instead of wood wouldn't have been a bad choice either, and the container to store the pieces should've been hard transparent plastic instead of the malleable sheet of plastic. I understand, however, that this was a first edition and the funds were probably scarce to get top quality materials, but here's hoping for a second version with better materials and a nicer overall appearance.

Availability: I purchase the Qboid at eBay for £10 (plus £4.75 shipping), but you can also get them at Clear Sites (in the U.K.).

(Click to Enlarge) - Level 1: Alternative Layout

The Great Z Cube is a very nice puzzle that I got in my latest Brilliant Puzzles order. Probably not so well known as the Great Y Cube, which to my knowledge is designed by Jean Claude Constantin and known simply as 25Y, but it's also equally hard - Extremely hard.

The puzzle has 25 identical Z-shaped pieces and the object is to build a 5x5x5 cube. There are also other less complex shapes that you can try to build, besides the cube and with less pieces, but I have been so immersed with the main goal that I haven't even tried those yet.

The design of the Great Z Cube is superb and the quality is very good as well. It comes in a die box with holes instead of dots and completely made of natural wood. Worth noting is that the configuration of the holes matches exactly the ones in a real die (adding opposite faces equals 7). The holes in the box have a darker contour to them, which looks great contrasting with the wood tone.

(Click to Enlarge)

The difficulty of this puzzle is one of the greatest that you can find in any assembly/packing puzzle. I haven't tried such a tough puzzle since Conway's Packing Box (Shipper's Dilemma). Suffice it to say, I haven't been able to solve it yet and I have little faith that I ever will. It doesn't seem so complex at first - How can 25 identical pieces be so damn hard to pack, right? - It just is... In fact, the identical nature of the pieces is what makes it so difficult, because there's literally millions of possibilities to stack the pieces the wrong way. I'm not sure the exact number of solutions, but I reckon even Burr Tools will choke trying to solve this. I have been trying to solve it, not exhaustively, for the past couple of months and the best I can do is to get all but one piece inside.

I'm sure there's a better strategy than just randomly stack pieces on top of others, and with a thorough mathematical analyses, one can easily find the right solution. I'll have to leave that to the experts, I'm afraid, as I lack the proper mathematical skills needed for this task. If by any chance someone finds the number of possible solutions, leave a message in the comments section, and I'll be sure to update the information on the post.

Update: Thanks to my fellow puzzle blogger, Kevin Sadler, I now know that the puzzle has four distinct solutions. There's still hope to find at least one... or not! Thanks Kevin ;)

(Click to Enlarge)

The Great Z Cube is available at Brilliant Puzzles for about $15 USD.

Closing Comments:

Despite not having been able to solve it (...yet, hopefully), I have to say that the Great Z Cube is a fantastic puzzle. From the amazing design to the ultra challenging task, this is everything an experienced puzzler could ask for. Not for the easily frustrated casual puzzler.

After five weeks reviewing the different puzzles available from Roscreative, by Valery Rudenko (English), I finally reach the last puzzle, the Rudenko Clips.

First released in June 2010, along with the Doser, Mosaic and Matryoshka, the Clips puzzle is another great implementation of the Tower of Hanoi concept. This small and very simple puzzle has seven clips in three different colors and measures 8 x 6cm (about 3" x 2.4"). The rules are also simple, but with a big exception: It's not possible to cheat.

I would have preferred if it were seven different colored clips instead of just three, but there's a reason for that. You can play other types of game with different rules: Besides getting all clips from one sector to another, you can also get clips in all three sectors with different colors. For example, get only red clips in sector 3, green clips in sector 2 and yellow clips in sector 1. Below left is one example and on the right, a table with other examples.

(Click to Enlarge) - Other possible playable games

The puzzle has three sectors and you have to move all the clips from one sector to another, one at a time. The same rules from the Tower of Hanoi apply, in other words, you can move a bigger clip onto a smaller one, but not the other way around... And here's the interesting part: even if you wanted to cheat, and tried to move a smaller clip on top of a bigger one, it's physically impossible. Another obstacle at moving clips the wrong way is the separation of the sectors, which prevents more than one clip to pass through at the same time.

The design of the puzzle is fantastic, something worth praising. The simple concept is great at hiding the complexity involved in it, and the thought that went into the making of a cheat-proof puzzle is just amazing. A nice feature is that the puzzle is double-sided, meaning that it can be used by both left-handed and right-handed people. It's a great feature for me, being left-handed to be able to enjoy the puzzle in the same way. Another nice design feature is that the clips aren't perfect rectangles; they have a subtle slight narrower diameter towards the top, which allows them not to tangle so much with with the other clips when you're moving them.

(Click to Enlarge)

Solving the Rudenko Clips requires a lot of patience and concentration on your part. The puzzle has five levels of difficulty, so you can start by moving just three clips to another sector and then work your way up until you reach the seven clips.

Just for you to have an idea of the steps and level of complexity in this puzzle, the Rudenko Disc and Rudenko Matryoshka (both related to the Tower of Hanoi as well) required a minimum of 127 moves from one sector to another, and the Rudenko Clips require a staggering 729 steps, mainly because of the limitations when moving clips from one sector to another.

(Click to Enlarge)

My take on this whopping number of steps is that it's not much harder than the less complex puzzles. It just takes more time to solve and requires much more concentration, especially not to lose your train of thought, and believe me, you will most certainly lose it. I had to gather my thoughts a few times and check where I was, before venturing any further. The other puzzles took about 10, 15 minutes to be solved in the first time, but this one took more than an hour. My advice to you when solving it is that it's best to solve it in one go and not to leave it half solved for another day, because it can be difficult picking up where you left off.

I added below two interesting documents about the Rudenko Clips, one explaining in more detail the facts about the puzzle in relation to the Tower of Hanoi.

Video: Youtube video with the designer, Valery Rudenko, showing the Clips puzzle.

Closing Comments:

The Rudenko Clips is definitely not for the casual player. It can be frustrating at times, particularly if you're close to the end and lose your concentration, but at the same time, it's a wonderful challenge and very rewarding when you finally solve it. Would recommend it to any sequential puzzle fan.

... And there you have it. Five great Russian puzzles from Roscreative and all designed by Valery Rudenko. My favorites were the Disc and Mosaic, but the others are not far behind. They're all fantastic collector's items.

Availability: You can buy Rudenko puzzles at Hendrik Haak's Puzzle Shop, from Germany or Labirint.ru in Russia (English translation here). For wholesale, contact Roscreative directly.

Now available on PuzzleMaster as well.

Links: 

English translation of Rudenko Clips' page

English translation of Roscreative website

Russian Magazine Article about Valery Rudenko (English Translation)

Russian Newspaper Article about Valery Rudenko (English Translation)

Cannonball is another puzzle designed by Mike Reilly. A couple of weeks ago, I also reviewed his Reilly's Cube (see here). The first version of the Cannonball was first produced by Skor-Mor, way back in 1973. An interesting fact is that there was included with the puzzle, a booklet with flat shapes that were possible to build with its pieces, reminiscent of the Tangram.

The Cannonball is comprised of seven pieces, all dissimilar and with a common characteristic: each one is a different configuration with 5 cannon balls, for a total of 35 balls. The goal is stack all seven pieces into a 5x5x5 pyramid shape. The puzzle measures about 13cm in base length (roughly 5"). Also worth noting, the base is carved with 15 semi-spheres, which is a good way of keeping the pieces from moving. Very nice design feature.

(Click to Enlarge) - The 7 Pieces

Every since I started my collection, I had a particular taste for pyramid shaped puzzles. I have now several of them and a few with this type of cannon ball design. My guess is that they were based on Mike's old design, since his, dates from 1973. From the designs I have, two are closely related: One is called the Infernal Pyramid. It has six pieces as well, but it's only a 4x4x4; The Stacking Pyramid, on the other hand, is a 5x5x5, except for its 10 pieces. Here, more is less actually, because the 10 pieces make the puzzle a bit easier, since the pieces are a mixture from two to four balls glued together - None of them is a 5-ball piece, so the complexity level is much more simple, thus making the puzzle easy to solve.

While the concept of the Cannonball was a little similar to what I already had experienced, I was still curious to try one with 5-ball pieces. I have to say, I wasn't disappointed... Solving wise, the puzzle is quite the challenge. It took me two sessions and a total of about two hours to finally solve it. The hardest part was finding the correct orientation for a couple of pieces that seemed not to fit anywhere. In most of the pieces, I had a pretty good idea on how they would appear when correctly placed, but these two were just a pain to figure out.

I just have one remark regarding the finished appearance of the puzzle. When solved, the pieces don't seem to perfectly fit together and viewed from different angles, it gives the impression that there's still room to align them, but no matter how you manipulate the pieces, they always seem out of place. At first, I thought it was just me that didn't solve it correctly. However, after carefully inspected the solution sheet, I could see that there wasn't anything wrong with my solution. It's a tiny design flaw that affects the overall look of the puzzle, but nothing that will spoil your solving experience.

(Click to Enlarge)

Closing Comments:

Despite the apparent misalignment of the pieces, the Cannonball is a very nice puzzle. It will certainly provide you with a tough challenge and some serious creative thinking before you can say, "Solved!". Definitely recommended for a more experienced puzzler.

Availability: The Cannonball is available at Puzzle Crafthouse for $20 USD. For an easier challenge, you can get a smaller 4x4x4 Cannonball puzzle instead.

Vinco (Václav Obšivač) is best known for his extraordinary coordinate-motion puzzles. However, the one that I have for review today is not one of them. The question is, does it compare to his best work? - Keep reading to find out.

A few months ago, I reviewed the Triangle Vinco, with a somewhat similar style to this "mini AC3". As the name suggests, this is the third version of this puzzle. The first two have a slight difference in the piece configuration, albeit looking identical. The six pieces are all dissimilar, being a combination of two different sized right triangular prisms, glued together at different angles. When solved, the puzzle forms a perfect square prism with dimensions of 5.5 x 3cm (2.2" x 1.2").

Viewed from above, the puzzle has a beautiful eight-point star appearance, accomplished by overlapping the squared puzzle shape with the frame at a 45º angle. At the corners of the frame's base are four triangular prisms, the same size as the bigger ones seen for the pieces. These columns help to give a clear notion of the puzzle's borders, thus making a bit easier to assemble it back to its original form. Even so, there's nothing about the puzzle that makes it easy... Quite the opposite, actually.

(Click to Enlarge) - Partially Disassembled

The mini AC3 came from PuzzleMaster and it's rated at 9/10, just shy of the hardest difficulty. It's not a 10, because there are others, also from Vinco, that are a daunting task to solve. It's more like a training if you plan to get any of the harder ones. I have the Square AC2, which fits this category, but that's for another day...

Because I had a bit of solving experience with the Triangle Vinco, I wasn't caught off-guard, as I was already expecting that kind of non-intuitive piece interactions. Since the pieces don't fit exactly in an orthodox way, it can get rather difficult to recognize the correct patterns and how a specific piece can be placed in the frame. There are at least two pieces that are easier to place than the others, for their peculiar shape. In the photo below: top layer, middle piece and bottom layer, third piece.

(Click to Enlarge) - All 6 Pieces

The first of these two pieces is the easiest and can be placed between any of the four corners. The second piece is not so straightforward, because there are other three pieces that can fit together with it. A trial and error approach is the best option here, but with the first piece already placed, it shouldn't be that hard. The other pieces don't offer any type of hint whatsoever, as to where they might be placed. It took me approximately one hour to figure out the correct configuration, and even then, I tried to solve it a second time after taking the photos, and it took me another 15 minutes or so to solve it. Definitely a tough challenge.

Closing Comments:

At the beginning of the review, I asked if the mini AC3 could be compared to Vinco's best work. My answer is, absolutely! - This puzzle is a serious challenge for any experienced puzzler and the exquisite design is just what Vinco has been presenting to us all these years - A truly satisfying solving experience.

Availability: The mini AC3 is available at PuzzleMaster for a very affordable $12 CAD. Also available, are many other puzzles from Vinco with the same type of pieces and a similar concept. Ahead is a small list of such puzzles: Eight Houses, Cube 3, Minibox C2, Minibox Q1.5, Three Wedges, Triangle 9x3, Triangle AC2, HCP1, HCP2, HCP3, Hexagon AC, Rectangle AC2, Sandwich, Square AC2 and Square AC3.

Links:

Vinco's Official Website

Spin to Win - No, it's not a casino game or something like that. This puzzle was first produced by the Czech puzzle company Clever Toys, and was originally called Tower.

Manufactured for Brilliant Puzzles, the Spin to Win puzzle is similar to the concept of the classic Babylon Tower, but with a few key differences, besides from being a wooden puzzle. It measures 11 x 7cm (4.3" x 2.8") and instead of six columns and colors, there are only four, and instead of six  rotating discs, there's only two. Now, you might be wondering - Is it easier than the Babylon Tower? - The short answer... Yes, it is. However, it's not as easy as you'd think.

The fact that there's only two discs (or cylinders), adds some level of complexity and requires a different solving method than the one you're used to in the Babylon Tower. The original state shows the 20 colored balls aligned  in four groups. By the way, the balls are colored wood and not plastic, and the colors are a bit more washed out, not as bright as it appears on the puzzle's website.

(Click to Enlarge) - Scrambled

Each disc carry two balls from each color and rotate independently. At the bottom, there are four cavities for the balls that indicate which color should used in the columns and at the top there's only one cavity that will create a gap in order to scramble and solve the puzzle.

On my first try, it took me approximately 20 minutes to solve it, and I spent a good 5 minutes just to scramble it properly. Because of the two cylinder dynamic (or lack of it), it gets a bit slow to get the balls where you want them. When scrambled, it does get a lot more interesting to solve. The first step is to get the bottom cavities with the four different colors and work your way up - First the bottom disc and then, the top one. I think the hardest part was the final steps, as I couldn't manage to get the right color sequence. After a few missteps, the puzzle was finally solved.

(Click to Enlarge) - Solved

The Spin to Win puzzle is available at Brilliant Puzzles for $15 USD.

Closing Comments:

I liked the different approach to the this type of puzzle. It adds a new twist and level of complexity without being too difficult. The only boring task is getting the puzzle scrambled. I also liked the contrast between the wood tone and the colored balls, although I would've preferred the original brown scheme, in harmony with the rest of the puzzle. Overall, it was a nice little challenge.

Today, I'm going to describe the fourth puzzle from Roscreative, the Rudenko Doser, designed by Valery Rudenko (English). Check out the three previous reviews here, here and here. Only one left...

The Rudenko Doser is unlike any other puzzle you've seen. This very original design reminiscent of an hourglass is based on the task of mathematician Siméon Poisson for measuring liquids. There are three vessels: the main one is connected to the two smaller vessels with taps to open and close the flow of "liquid" (represented by a green sand-like material). The puzzle is double-sided, as the smaller vessels are marked with capacities of 5 and 3 liters on one side and 7 and 5 liters on the other. There's also a tap between the smaller vessels to pour "liquid" from one to another.

(Click to Enlarge) - Hard Side

As mentioned above, there are multiple tasks for you to try and solve, more specifically, three on each side: On the easy side, with marks for 5 and 3 liters, you have to successfully measure 2, 1, and 4 liters; On the hard side, with the 7 and 5 liters, you need to correctly measure 3, 4, and 1 liters. These number sequences are in order from easier to harder. Also, note that the marks are just representations of the actual measurements, as the puzzle is relatively small, at about 9 x 9cm (3.5").

Solving the puzzle's challenges is not that difficult, even the ones on the harder side. Most of the tasks require multiple dosages in each vessel to get to the desired measurement, so the hard part might be to plan in advance how you will distribute the "liquid" back and forth. As an example, I'll describe below one of the easier tasks for you to get an idea on how to solve them, but the other ones follow the same exact logic, only lengthier.

(Click to Enlarge) - Both Vessels Full

So, one of the challenges is to accurately measure 2 liters with the 5 and 3 liter vessels. The first step is to completely fill the 5 liter vessel. When you're done, rotate the puzzle counter-clockwise by 90º and open the green tap, the one between the two smaller vessels. This action will allow you to fill the 3 liter vessel, leaving the rest of the "liquid" in the 5 liter one. What you see left in the 5 liter container is the exact measure of 2 liters. The other challenges won't be that simple, though, but still solvable within 5 minutes each. It took me less than half an hour to solve all six tasks.

Video: To have a better idea of how the puzzle works, check out this video with Mr. Rudenko.

Closing Comments:

If you loved mathematics related tasks or computer science projects in school, then you're certainly going to enjoy the Rudenko Doser. What I liked most about it was the hourglass appearance - It's definitely quite a unique design. Be careful when maneuvering the puzzle, though, as it tends to shed some of its green sand particles here and there. Nevertheless, it's a great looking puzzle and I can surely recommend it to any puzzle enthusiast.

Availability: You can buy Rudenko puzzles at Hendrik Haak's Puzzle Shop, from Germany or Labirint.ru in Russia (English translation here). For wholesale, contact Roscreative directly.

Now available on PuzzleMaster as well.

Links: 

English translation of Rudenko Doser's page

English translation of Roscreative website

Russian Magazine Article about Valery Rudenko (English Translation)

Russian Newspaper Article about Valery Rudenko (English Translation)