Cube+

Cube+ is my first experience with this sort "shape forming" puzzle. This puzzle came to me courtesy of David Goodman during the IPP34 Puzzle Exchange in London last year.

I am not sure what the wood used is, but it looks pretty well made by Gaya Game (this is the first time I have come across this online seller and they have a pretty decent catalog of products). 

Challenge #1 - Use all 7 pieces

The puzzle contains seven pieces comprising three congruent pairs. Each piece per pair consists of five units. The seventh piece is two units long. There are two challenges here; the first is to use all seven pieces to form a typical "burr" shape and the second is to find six pieces to form a 3 x 3 x 3 cube. As of late, there are quite a number of these designs from various puzzlers the goal which is to form a 3D symmetrical shape of one type or another.

Challenge #2 - Use 6 of the 7 pieces

For some strange reason I started off with the second challenge and oddly enough, I managed to solve the puzzle rather quickly within twenty minutes or so of fiddling. However I took well over forty five minutes for the first challenge which I thought would be the easier challenge since all seven pieces have to be used. 

I won't say the puzzle is by any means easy but its not that overly difficult either. And I am happy to report I didn't have to resort to Burr Tools! There must be only one unique solution to either challenge also, I would assume. For both challenges, especially the first, some logical thinking rather than random assembly would certainly help with the solve.

A Voyage To Terra Australis

Here's a 2D packing puzzle that I have been toiling over on and off the last several weeks...but got nowhere.

It's Brian Young's IPP34 Exchange Puzzle, designed by Junichi Yananose with an Australia theme. Its a "double-sided" packing puzzle because the twelve pentominoe pieces are printed on both sides with the Australian coastline. The description states...

The puzzle is to help Matthew Flinders fix his map of the Australian Coastline so that the entire coastline joins up and makes a correct map of Australia....Matthew Flinders and his crew had a few extra tots of rum as they were sailing past Bundaberg; in fact they must have used up the whole quota for the trip because they were way off course. They thought they had found the great inland sea but it was really Uluru sticking up out of the desert! You need to help them redraw the map of the Coastline so it joins up correctly and they can get on their way back to England to report to King George III.

The object is to rearrange the pieces to fit the tray and get the coastline of Australia correct but some of the pieces have to be flipped over to complete the puzzle correctly. 

According to Brian, "there are 2,339 different ways to pack the twelve pentominoe pieces into the 6 x 10 unit rectangular frame. And that number does not include the permutations of flipping pieces". However the way the puzzle has been designed, it has only one solution! The puzzle is made of laser cut hoop pinewood and lacquered.

If you are not sure what the outline of Australia looks like, or want to get more information about this beautiful country which I had the opportunity to visit twice in the past (Perth and Melbourne), click here.

The puzzle came with a scrambled (wrong) coastline and despite my many attempts at trying to get it right, each time I came up short. This is a very difficult puzzle (even tho' it appears to look easy) from what Sue (Brian's wife) tells me, after I threw in the towel and emailed her for the solution. Looking at the solution, well it looked rather do-able...and I got the "how come I didn't try putting that piece there?" questions running through my mind. I had missed some things that with more careful observation, I would have spotted. Sigh!

A Voyage To Terra Australis (and other exclusive past IPP exchange puzzles) is available at Brian's site Mr Puzzle for AU$27.50. 

Pocket Pento - The Search For Symmetry

I was very pleasantly surprised when I received an email from Eric Fuller a couple of months back. He had asked if he could make copies of my Pocket Pento for sale on his website together with some other puzzles he was also planning on making. He had spotted my Pocket Pento design published on PWBP and thought it would make a nice addition to his offerings. Of course I said yes without hesitation (well, who wouldn't?) and even emailed him several variations of the design for him to pick from. The next thing I knew, he had made the first copy and posted it on his FaceBook page.

Wow, this was the first time I have seen a design of mine made into a working copy (well, not really the first time as such; other puzzlers have made copies of some of my other designs) but the first from a master puzzle craftsman producing it for commercial sale.

The Pocket Pento is actually one of my early designs, my fourth that was published on PWBP. At that time I was trying my hand at designing and packing puzzles were the easiest and logical choice to begin with. Thanks to Goh Pit Khiam who taught me the use of burr tools and gave me loads of useful advice, I managed to come up with five designs of various shapes and sizes with the common theme of using all twelve flat pentominoes. As the name implies, the Pocket Pento was intended as a small-ish and flat-ish puzzle that could easily be put into the pocket and taken around. The version made by Eric with half inch square units is on the larger size of things and probably would only fit into pants, jacket or trench-coat pockets and handbags.

Eric made the Pocket Pento box out of Maple and the pieces in twelve different exotic hardwoods. The box had acrylic transparent sides which displayed the pieces in the solved state. A really nice touch which shows off the contrasting coloured woods very well. Construction and finish of my copy is excellent with very fine beveling of the edges on the pieces. The fit is very good and everything slides smoothly with no "looseness" of any sort. Thirty-nine copies were put up for sale on Eric's site at US$84 each; and like most of Eric's puzzles, all were sold out within a day or two.

I am not sure if owners of the Pocket Pento have noticed this....the placement of holes on the two sides, the entry/exit point and opposite bottom all have a certain "similarity" of appearance. I was not content to just design a box to house the twelve pieces (which is not too difficult) but I wanted something more...a "symmetry" to the overall look and shape, to make the puzzle as unique as possible. I think close to 100% symmetry may have been possible if Eric had used an acrylic plate to seal the bottom holes instead of another layer of wood which added an extra half inch to the height of the puzzle. But then again this may have affected the overall construction and aesthetics somewhat...and well, Eric's the expert so he must have known what he was doing. 

The puzzle is not easy by any means and I too have had problems remembering the exact sequence of moves and once or twice resorted to burr tools for help.

Thanks very much to Eric for turning my design into reality and I am happy to know that there are thirty nine other puzzlers out there in the world with a Pocket Pento in their possession!

Hanayama Cast Hexagon

Update 24 October 2017 - Dear Reader, please check out my new puzzle blog and e-store at http://mechanical-puzzles.com

The Cast Hexagon is the latest Cast puzzle to come from the Hanayama stable. The Hexagon was designed by Mineyuki Uyematsu who gave us wonderful packing puzzles such as the T4-II, T4-III and Caramel Box. 

The Hexagon also won the Jury Honourable Mention Award at the IPP34 Puzzle Design Competition. It was originally called "The Claws Of Satan" during IPP34 but it would have sounded very weird if Hanayama had used the name "Cast Claws Of Satan" or worse still, "Cast Satan"! Hexagon definitely sounds more appealing.

The Hexagon appears to be made of steel (I think) and in two colour tones. The choice of external finish for the Hexagon is IMHO really nice for this one, in matt silver and dark grey and not some gaudy chrome or shiny brass.  Construction and quality of my copy is very good and everything moves smoothly as intended.

The object of the puzzle is to separate the three "claws" from the base plate. When you first start to explore the puzzle, all the "claws" or pieces are able to move in various directions but all are locked within the confines of the plate. The pieces are able not only to move linearly but can also rotate at certain positions within the plate. As you puzzle on, hopefully you will be able to understand the trick of the puzzle and how to get the pieces "out". 

I do not want to give too much away here to spoil the fun of still many puzzlers who have yet to get a copy. But like an interlocking burr, once you get the first piece out from the plate, the rest of the pieces come off much easier. It took me about fifteen minutes to disassemble the Hexagon...but it took me a good hour to reassemble it! Because I had forgotten the positions of the pieces relative to the plate and their orientation during the taking apart. While I could get all three pieces back within the confines of the plate, I hit dead ends quite a couple of times and had to disassemble the whole thing and start over again. If you want to, take photos as you go along, so the reassembly will be less frustrating.

The Hexagon is a very nice addition to the Hanayama Cast range. Nice design and well made. For the price of a typical cast puzzle, a lot of puzzling for the money. Its rated four out of six stars for difficulty and this I feel is about right; challenging yes, but not frustratingly so. A great addition to any collection and a must-buy for cast puzzle lovers.

As far as I can tell, the Hexagon is only currently available from PuzzleMaster of Canada for CA$12.95. Eventually it will make its way to other online sellers, including Amazon. Those living in Asia may want to buy direct from Mineyuki via his website. Its in Japanese but click on the link at the lower left sidebar - "overseas mail order", while those in Europe can buy it from Eureka Puzzles.

Marble Cake

Now here's an interesting packing puzzle I played with over the weekend. It's called the Marble Cake and is the brainchild of my puzzle friend Frederic Boucher. Not only did he design the puzzle, he also made it....without using any wood cutting equipment!

I got to know Frederic two years ago after acquiring his IPP33 puzzle design competition entry, Manholes 55. Frederic is a French Canadian who presently lives in Tokyo, Japan. While back in Canada he had his own wood workshop at home, this is not possible for him in Japan since his dwelling cannot accommodate such a setup. Fortunately Frederic is able to order and get his wood cut into specific size blocks and then he sands, glues and finishes them into the shapes and pieces required. Looking at the quality of the Marble Cake, you wouldn't be able to tell that this was the way Frederic put together his puzzle.

The Marble Cake consists of a bottomless tray made of Japanese elm with seven different pieces made from exotic hardwoods including Japanese beech, magnolia, paduak, teak, wenge, ebony and cherry). Construction and finish is very good indeed and the fit is just nice with the right amount of tolerance between the pieces. 

Three of these tetraminoes....are not like the others....

All seven pieces consist of four units each (tetraminoes) in various shapes.Nothing too unusual about this; except that three of the seven pieces, tho' they are four units a piece, are nevertheless joined together to form rather "odd" shapes (as shown in the photo).

As a result, this makes the Marble Cake far far more tricky and difficult than if it had just been a packing puzzle with seven regular tetraminoes. It took me a good hour or so before I got all the pieces flush into the tray!

If its any help, the trick I suppose is not to think of the odd pieces as odd if possible, but to see how they could possibly fit into the tray if they were just regular tetraminoes (which of course is easier said than done, with the benefit of hindsight).

This is really a very nice packing puzzle with a good level of challenge. Its difficult but not frustratingly so. An original design and with only one solution. For packing puzzle fans, the Marble Cake is a must-have for collectors.

[Edit 12 May 2015: There have been a number of readers asking how they can purchase a copy of Marble Cake from Frederic. Please email me via my blog email and I will put you in touch with Frederic directly]

Chicken Puzzle

There are many wooden animal puzzles around. Most notably from the Japanese Kumiki puzzles genre as well as the Karakuri Creation Group. All sorts of animals abound including lions, pigs, cats, elephants, owls and even the skunk.

Then there are some from European craftsmen like Alfons Eyckmans which are more conventional burrs but containing within the puzzle an animal-shaped piece, like his Gobi and Free The Monkey 2. Once in a while, someone comes along and designs a burr puzzle but deliberately fashions it in the shape of an animal. The Chicken is one such puzzle.

A really cute puzzle I might add. the Chicken was designed by Olexandre Kapkan and made by Eric Fuller. Excellent craftsmanship as always and the woods used here are Yellowheart and Cherry; no doubt to reflect the colours of a real chicken as far as possible.
The puzzle is about the right size for comfortable handling, measuring about 10.5cm x 6cm x 5cm. It's actually the size of a large chick. This puzzle was the first to sell out after Eric announced his site update. I was lucky to get the last copy.

According to Eric's Facebook post, there is suppose to be a surprise hidden inside the puzzle (eg Egg?) but I didn't find anything as I played with it. Although it is Level 10.2 with only four pieces and the body, its not an easy puzzle to solve at all. After like moving 5 or 6 steps, I got stuck. Took me the good half an hour to find the correct move and then finally got one drum (I mean leg) of the Chicken out. The rest of the other limbs came out easily after that. Putting it back together was about just as hard as I had to do everything in reverse. I couldn't quite remember all the steps and was forced to do some trial and error before I assembled the lot together. Burr Tools not needed here (at least not for me).

The Chicken is really a great puzzle, not only in terms of the design and look (displays very well and attracts comments) but it also offers a good level of challenge from the puzzling perspective. I only wish those beautiful and superb quality Karakuri animal puzzles can be designed with this level of difficulty, then they will really be outstanding puzzles.

Find The Lid

"Find The Lid" is an interesting trick opening "box" from Tatiana Matveeva of Russia. This was her exchange puzzle at IPP34 in London last year. It's not really a box per se, but six panels with notches interlocked together to form a cube.

The object, as what the name says...is to find the lid (and open the box). The panels are numbered from 1 to 6. Overall construction of the box is good and the panels all appear to be laser cut and fit nicely. Inside there is a coin (a Russian 10 Koiieek) thrown in for good measure (as I later found out after opening the lid) to be discovered.

Its obvious that to find the lid, one would have to press, tug or pull each of the six panels to see which one will move. I quite easily found the single panel that could move but the puzzle is not so straight forward. The panel moved about 1 to 2 mm and thereafter got stuck. It is held back by some restraining mechanism. Ha! not so simple after all!

It took me several minutes trying before I figured out the "trick". Not a totally new or novel locking mechanism that holds the lid, but pretty cleverly applied to this puzzle, considering the puzzle is no bigger than 6cm all round and each of the panels is only about 8mm thick.

No force is needed here. In fact if force is used, the puzzle could possibly end up damaged, especially the internals. A nice exchange puzzle, thanks Tatiana!

Three Coffins

This week saw the arrival of three "coffins" to my home! Three Coffin-designed packing puzzles to be accurate. They are:-

1. The Cruiser
2. Five Fit - Stewart Coffin #177A
3. Martin's Menace - Stewart Coffin #217

The Cruiser

All three puzzles came to me from Creative Crafthouse. Creative Crafthouse has a very extensive catalog of wooden puzzles and games and the company manufactures most of their puzzles in their shop in Florida, USA. They also design their own puzzles. 

All of the three packing puzzles are precision laser cut. Quality, fit and finish is very good. The pieces and tray are made from different hardwoods (and I have asked Creative Crafthouse what these are) while the base of the trays are made of floorboard. Don't let the word "floorboard" put you off; it is extremely sturdy, scratch resistant and durable and can withstand a lot of abuse. You can even clean it, tho I won't recommend using any floor cleaner! Other nice touches include the names and other details etched onto the tray. 

Ranging from US$12 to US$21, these three puzzles represent excellent value for money. Cruiser and Five Fit also come in larger sizes.. What I also really like is that all three puzzles came to me upgraded with tray covers; which makes the puzzle look nicer and storage much neater.

Five Fit - Stewart Coffin Design #177A

I started with what appeared to be the easiest of the lot; Cruiser. Only four piece made up of two congruent pairs of shapes. Not too difficult and I managed to solve it in under five minutes. According to the grading given by Creative Crafthouse for time it takes to solve (less than 1 min - Gifted, less than 5 mins - Smart, less than 10 min - Normal, less than 20 min - Slow,  Never - Sad Situation), I fall into the smart category; for this puzzle only!

My next attempt was with Five Fit. This one consist of five pentominoes. And much tougher than the Cruiser. I must have played with this for nearly half an hour before I finally figured it out. I don't want to have any spoilers here but suffice to say there is a "trick" to this puzzle. You will go around in circles (even tho only five pieces) if you don't discover the trick. Again I have some experience with such packing puzzles and this helped my solving.

Two packing puzzles is enough for one day. I am leaving the last; Martin's Menace for another time and will post a review once I have played with it. It is supposedly a very difficult puzzle from the description. I don't know how to do the "hide/show" thing here, so if any reader wants to see the solutions for the first two puzzles, please PM me and I will send you a photo.

For anyone interested in packing puzzles, these three are great to collect and for beginner and experienced puzzlers alike, its definitely worth checking out Creative Crafthouse's range of products, which judging from these three puzzles, are both high quality and affordable. 

TetraParquet

Here's another interesting co-ordinate motion puzzle I played with earlier in the week. Both in terms of the puzzle design and the physical shape. Anyway I needed something less stressful after my struggle with the Optiborn.

TetraParquet was Stan Issacs' IPP34 Exchange Puzzle in London last year. The puzzle is triangular shaped and consists of six (also triangular shaped) pieces. Its called "TetraParquet" because the puzzle has four faces, and each face consist of a further three triangular faces. It was both designed and made by Wayne Daniel out of exotic woods; which I think is Maple, Paduak and Walnut. The woods give it a symmetrical 3-colour contrast. Construction, fit and finish is very good and everything slides smoothly. Reminds me of the Cast Delta, but in 3-dimensions.

Object of the puzzle is to take apart the six pieces and reassemble. Each of the six pieces have triangular "plates" glued and attached to the edges. These plates are the connectors between the pieces which holds and "lock" the puzzle in place. Very delicate looking parts!

Taking apart is not too difficult (unlike the Pennyhedron puzzles reviewed previous). Some manipulation and you can begin the feel the joints coming apart as the pieces start to split. Putting it together is harder as the pieces only fit together one way (meaning you can't interchange the positions of the pieces since the plates can fit into adjoining pieces only if the pieces are correctly matched). You start off by building two halves and then bring them together. There is then a need to maintain the six pieces slightly apart (not too far that they are totally separate) and slowly ease the six towards each other. Tricky and it took me a bit of fiddling to finally get the puzzle back into the solved state. 

Not a overly difficult puzzle by any means, but certainly it displays very nicely! 

Optiborn

No way! - my first thought after reading Kevin Sadler's review of Optiborn. He had mentioned:- "don't be put off by such a high level - this is definitely solvable by almost any puzzler".

I was not put off by the level 27.2.5.2 of this puzzle...not at all. I was just stumped and stuck like after 10-12 moves...well, more on the solve later.

Optiborn is from the most recent range of puzzles offered by the Pelikan Workshop. I had gotten it together with Castle, reviewed previously. Made of Paduak and Walnut, the puzzle is very well constructed with superb quality and finishing. Nice touches include the fine beveling of the edges and the name of the puzzle engraved on the cage! 

The Pelikan Workshop have always produced quality value for money puzzles in the past. But with their newly revamped website, the level of quality has also correspondingly gone up a few notches as well.

Optiborn was designed by Stephane Chomine, who has done a staggering 497 designs in the last five years, since March 2010. That's an incredible average of 2 designs every week! 

Not a large puzzle by any means, the Optiborn measures about 6cm x 4cm x 4cm. Externally, it doesn't look intimidating, sporting a minimalist look with four regular burr pieces and a ordinary looking cage. But this is a tiger in sheep's clothing! Its really tough...at least I found it so. So don't believe Kevin what he says. After all, he's quite an accomplished burrist, but not so much of a packist (the latter by his own admission; "packist"- one who plays with packing puzzles).

I wrestled with Optiborn for quite a number of evenings; in between playing with other puzzles but got nowhere. Usually hitting a dead end after a number of moves. Finally I threw in the towel and configured the design in burr tools. The first 27 moves look so convoluted and confusing that I knew I wouldn't have been able to solve it on my own. 

Its one thing to design high level burrs using all sorts of notches, grooves, cuts with numerous pieces and odd shapes. But in my opinion, a really good design is one like the Optiborn - innocuous and simple looking, with regular shapes and few pieces...yet in terms of difficulty, punches well above its weight!

Little doubt that those who are into burr puzzles would enjoy this one! And great value for money too! 

Orchid Pennyhedron

A while back, I played with Stephen Chin's Rose Pennyhedron. In my blog post, one reader had also offered an explanation of how the "pennyhedron" puzzles got their name. And there is some other general information on "Rhombic Dodecahedrons"  Over the weekend, I played with another similar puzzle, this time it's the Orchid Pennyhedron, George Bell's IPP34 exchange puzzle. 

The Orchid was designed by George and made by Stephen (or "Chinomotto" as he likes to be known). Quality of construction, fit and finish is very good with contrasting woods used.

Externally both puzzles look rather similar (both have six triangular "facets" to each surface) and both the Rose and Orchid are comprised of three pieces. However while the Rose has three identical (or congruent) pieces, the Orchid only has two. The third piece appears to be a mirror image of the other two.

Like the Rose, the object is to find a way to split the three pieces apart. This is a co-ordinate motion puzzle. The effort required here for the Orchid was no less than that of the Rose. In fact it took me a while longer to both take apart the pieces, and bring them back together again. The fit was so good I took some time to figure out where the pieces were suppose to come apart. Its likely to pose some difficulty to the uninitiated! 

But having played with the Rose previously, I knew what I needed to do. Some pressing at strategic spots and the pieces began to split gradually. I took two tries to reassemble properly as the first attempt did not get a perfect alignment of the three pieces, which resulted in a rather uncomfortable feeling rough edge between two of the pieces.

From what I understand, George and Stephen each have a whole collection of these pennyhedron puzzles, each looking very similar externally but all with various designs and interlocking. If you are keen to find out more or want to get one of these, these two gents would be the people to approach.

Push Box Puzzle

This is one of those puzzles I managed to solve but have no clue how I did it nor can I explain how the puzzle works!

The Push Box Puzzle came courtesy of Simon Nightingale during the IPP34 puzzle exchange. If you didn't already know, Simon was the winner of the Grand Jury Prize for the 2014 IPP34 Nob Yoshigahara Puzzle Design competition for his "Six Locks 2 Keys" puzzle.

The Push Box is made from Corian (the stuff that you would normally find on kitchen and sink counter tops). The puzzle is pretty heavy and well made in a nice light blue colour. The joint lines are well hidden and not obvious at all. It looks like Simon had dug out the insides to create the box. I am not sure how strong Corian is but I would think the box would likely crack if dropped onto a hard floor from anything more than 3 feet. The object is the push and "open the box" like a drawer.

The drawer is spring loaded and allows for some movement (several mm) inwards but there is hidden mechanism which keeps the drawer from coming out of the box. Inside there are a couple of ball bearings spinning around, which may or may not have anything to do with the locking mechanism (yes, there are some puzzles where ball bearings are red herrings; serve no function but to merely to confuse).

I fiddled with the puzzle for a while, trying to guess how the drawer is locked inside the box and how the ball bearings come into play. I pushed and released the drawer over and over again, turned the box at all sorts of angles and in all orientations, and all of a sudden, pop out comes the drawer. The drawer cannot be fully withdrawn and part of it remains inside the box. Again I am not sure if the drawer is intended to fully come out, but I don't think so. And the box also cannot be taken apart.

I managed to solve it a couple more times, more through trial and error, but not fully understanding how the hidden mechanism/trick works, at least not until I see the inside. And mind you, I have a fair amount of experience with trick/puzzle boxes. I have emailed Simon for the solution. Hope he replies soon. I am really super curious as to how it operates. I will update this post, once I have seen the solution.

When Is A Burr Not A Burr?

Answer: When it's Primitivo Familiar Ramo's "Murtbiter's Pseudo-Burr". 

This is my second puzzle from Primitivo, the first being his Twin Box Pentominoes, made by Brian Menold of Wood Wonders. The Pseudo-Burr was also Primitivo's IPP34 Exchange Puzzle!

Consisting of four congruent pieces and a cube, the puzzle gets its name from the fact that when put together, it looks like any other ordinary six piece burr. But its not! The pieces are actually cubes cut and glued together and quality is reasonably good. Primitivo's batch of exchange puzzles were made by Vaclav Obsivac of Vinco Puzzles.

The puzzle came unsolved, so the object is to assemble it to look like a burr. Its not a very difficult puzzle and I managed to solve it in under ten minutes. Certainly some logical thinking of how the pieces should fit with each other would help. The accompanying instructions and diagram shows the final shape of the burr. But this is one of those puzzles that with some persistence, you would eventually discover the solution. Nonetheless, still a bit tricky trying to figure out the four identical pieces. Kudos to Primitivo for coming up with such an interesting design!

From this to the "burr" above

Again, a puzzle "with just the right level of difficulty appropriate for an exchange puzzle". Quite easy to solve repeatedly after you have gotten it the first time round. And oh, if anyone knows the meaning of "Murbiter", please feel free to drop me a comment, thanks.

Cross Bones

This little black puzzle is Englishman Frank Potts' Exchange Puzzle at IPP34 in London last year. 

Can you spot the skull?

And unless I am way off tangent here or doing something wrong, the Cross Bones is one of the very few burr puzzles that I actually found easy to solve!

Physically Cross Bones looks similar to Frank's Level 24 Burr Bones sold a while back by Eric Fuller. Unlike its wooden cousin which comprises three pieces, the Exchange version is only two, interlocked together. And a lot easier! Frank has done a number of designs in the past, favouring in particular, three-piece burrs.

Cross Bones is 3D printed in ABS resin by Scott Elliot and the puzzle is rather diminutive, measuring about 4.5 cm across. Fit and quality is good. The two pieces are able to "lock" nicely without any free play. There is even a motif of a skull printed on one of the ends for added effect!

This puzzle is a level 6.1 puzzle and because its only two pieces, its a pretty easy solve. The moves are sequential with only one solution. The blackness of the puzzle also makes it a bit tricky to see the openings where the pieces can untangle themselves.

Easily pocket-able, the Cross Bones is a nice little puzzle good for passing to non-puzzling friends, who perhaps may require more than a little effort to solve it. Oh, and I forgot to mention, no burr tools needed here!

Double Heart Arrow

If there is a prize for the cutest looking Exchange Puzzle at IPP34, Yoshiyuki Kotani's Double Heart Arrow would surely be a top contender.

Not only is it cute, it's also colourful and whimsical looking. The puzzle comes unsolved in four loose pieces and the object is to "pierce" the heart with the arrow. All the pieces are laser cut from acrylic and quality very good. The heart consists of two identical pieces, one in red and the other pink. The arrow is split into two halves, in transparent orange and yellow.

Effectively, the Double Heart Arrow puzzle is like a four-piece board burr and solving it requires you to navigate the heart pieces through the notches and channels along the arrow. The end point is marked by etched markings so you will know when the puzzle is completely solved.

Although it looks simple at first glance, it is in fact not that easy. I found myself close to the finish several times yet the final position of the pieces eluded me; one of the pieces would always be just one step out of place and I had to start all over again. This is a sequential movement puzzle with only one solution, it would seem. Get the sequence wrong, and you would have to back-track your steps.

Overall a nice interesting concept and a departure from the traditional wooden burr style interlocking puzzle, even though the design and solving process are similar. Not easy by any means but not difficult either. And Its fun looking and colourful appearance serves only to make you want to persist until you solve it.

Heart In Puzzle

Here's another Minoru Abe sliding puzzle I played with the last two evenings. It's the Heart In Puzzle with three challenges. The object of each of them is to move the "Heart" block to within the confines of the four identical L-shaped blocks.

Like all current Minoru Abe sliding puzzles available on the market today, the Heart In Puzzle puzzle is well made and packaging is in the form of a nice dark blue box. The instructions are in Japanese but the diagrams are self-explanatory. 

The tray is (likely) made of  pine, while the pieces are a different species of wood. Despite its high quality, Minoru Abe sliding puzzles are not expensive and prices range from about 2,100Y (US$17) to 3,700Y (US$31). They are available from online seller Torito (which unfortunately does not ship outside of Japan), CU-Japan and Amazon. The Heart In Puzzle cost about US$17/-, one of the cheapest.

Start Position No 1

Start Position No 2

Start Position No 3

Each of the three challenges is represented by three starting positions and the first requires a minimum of 28 moves. Not a lot moves compared to Minoru's other sliding puzzles (some of them in the hundreds) but I found this one rather difficult. It took me a rather good portion of an evening to solve the first challenge and the same for the second challenge. I didn't attempt the third. All the moves are linear. Initially I was wondering if the Japanese instructions (which I can't read) allowed for rotations, because if it did, it took me well less than 28 moves to solve. A quick check with sliding puzzle supremo Nick Baxter confirmed no rotations allowed so I had to take the more difficult route.

Solved Position For All 3 Challenges

For those into sliding block puzzles, the Heart In Puzzle is a must have and great value for money. Oh, and incidentally, the Heart In Puzzle does bear some similarities to Serhiy Grabarchuk's 22-move Sliding Stones.

Castle

"Castle" is one of two puzzles that came to me from the Pelikan Workshop. If you have not checked out their new revamped website, you should. They have now got a nice clean looking and user friendly interface with nice photos of their puzzles for sale.

This is my first puzzle from designer Tzy-Chung Chein, who has done over thirty-six designs to-date. My copy of the Castle is made from Dark Oak, Mahogany and Maple. Construction and quality is excellent and everything fits well and slides smoothly. The finishing details are also amazing; just look at the decorative inlays at the four corners! At 9cm x 9cm x 6.5cm, this is a large puzzle and easy to hold and play with.

But Pelikan has gone a step further and taken their creations up a notch above the other handful of well known puzzle makers; Pelikan now laser engraves their puzzles with the puzzle's name. For the Castle, its found on one of the pieces. A really nice touch.

The Castle consists of a box cage and four congruent pieces. It is not an easy interlocking puzzle to solve, at least not according to its relatively high level 18.16.5.6 solution. The pieces are normal regular burr pieces but the cage which holds them has 8 protrusions inside, one of the most I have come across. Despite this, I actually managed to take the Castle apart and put it back together without the aid of Burr Tools. Not the intended way unfortunately, but via a short cut as the design seems to allow for an (unintended) rotation of one of the pieces. 

As a result, I got the first piece out in just under 10 moves! But still not easy by any means as the rest needed multiple moves especially the third and last piece which took me a while to figure out. Later on I configured Burr Tools for the Castle and indeed, as I discovered, the 34 moves for the first and second pieces are very tough; which I doubt I could have figured out on my own. 

The Castle is one of about half a dozen new puzzles recently offered by Pelikan, now available on their site. I am sure there will be more new designs which will follow soon. At 35 Euros, the Castle is also great value for money given the craftsmanship that comes with it.

Cast Keyhole

The Cast Keyhole is the latest Cast Puzzle from Hanayama and came to the market in 2015. It was designed by award winning puzzle designer Vesa Timonen, who has designed a number of well known Cast Puzzles available on the market today including the wearable Loop, Cylinder, Square and Donuts.

This puzzle came as a gift to me from another well known puzzle designer Goh Pit Khiam (thanks very much Pit Khiam!). The Keyhole is available from various online retailers including Amazon and Torito, however the latter doesn't ship internationally.

The Keyhole consist of two similar looking "maze" plates, resembling the jagged edges like the teeth of a key, which are interlocked together in the starting position. Object is to separate the two plates, via one of the openings on one of the plates. The Keyhole can perhaps be considered a much more difficult cousin of the Cast Key. Quality and finish is good and the Keyhole has a shinny finish. Usually I don't quite like polished surfaces, but for this puzzle, it looks fine. 

Its not a very difficult puzzle by any means and Hanayama rates it 4 out of 6 stars in terms of difficulty (ie fairly hard). But the Keyhole is not as straight forward as it may appear to be at first. In fact, Hanayama states on its site (translated from Japanese) that the Keyhole is a "3-dimensional" maze. Not sure tho' if "3-dimensional" is stretching it a bit here. 

As you play with the puzzle, you will discover that you need to shift the orientation of the pieces relative to each other to move the pieces towards the opening. But as you progress, some of the positions may result in a dead end. However with some persistence, eventually the plates will come apart. I was fiddling with the puzzle for several minutes trying this and that, and suddenly, one plate just came out and it was solved.  

A nice addition to the very extensive Cast collection. And as with the Cast puzzle series, value for money.