Jerry's Mechanical Puzzle & Brain Teaser Collection

I thought I would start my 401st post here with a brief mention of the above two puzzles, which lucky me, has been made into four different versions with four different sizes. First off, the 9 Blocks Box; this is a design I did in late 2015 which was produced several months later by Eric Fuller in a limited edition run of 50 copies for sale.

From Left: 9 Blocks Box (made by Eric Fuller), 9 Blocks Box (made by Frederic Boucher),
9 Blocks Cube (made by Eric Fuller) and 9 Blocks Cube (made by Tom Lensch)

The 9 Blocks Box comprised of a rectangular box and the object was to fit 9 irregular shaped pieces into it. It has a unique solution. I spent a fair amount of time trying to design all the blocks to be different from each other but in the end, I could only managed to do so with 7 of them while two of the pieces had to remain identical.

Eric's version of the 9 Blocks Box was small and constructed to fit a pocket. I think small is a bit of an understatement; it was Lilliputian. Each puzzle measured a diminutive 3.4 cm all round! Made of Holly, Zebrawood and Macassar Eboy, it was rather cute and certainly didn't go unnoticed, which saw all 50 copies sold out within a day after it was listed on his site. He also fashioned the box to have a cover that "locked" magnetically to keep the pieces in place (even in an unsolved state; quite clever I must say) and dimensionally the shape also became more of a cube as opposed to the original rectangular design.

A couple of months later, my puzzler friend Frederic Boucher made a limited run of just 5 copies (of which I received #1). He also upped the ante by machining the 9 pieces in gorgeous aluminium. Frederic's version was a real beauty and came with a wooden box with slanted corners and packaged in a plastic container to boot. He too, as I understand sold out all his copies after pictures of it were posted on Facebook.

9 Blocks Cube made by Eric Fuller

Sometime later, Primitivo Familar Ramos from Spain took my design and scaled up the original rectangular box to result in a cube. As a consequence, he was also able to resize the 9 blocks such that now, no two pieces were identical. We jointly entered this version, the 9 Blocks Cube for the IPP36 Nob Yoshigaha Design Competition in Japan last year.

The first working copies of the 9 blocks Cube produced for the competition were crafted by Tom Lensch. Our competition puzzle was huge! Each cube measured 12.6cm x 12.6cm x 11.4cm. Heavy and rather difficult to lug around. The box was made of Maple while the pieces Mahogany. We didn't win any prizes at IPP36 but this modified design again attracted Mr Fuller, who subsequently went on to produce 150 copies which formed the first release of his "Limited Edition" series via his upgraded website. Eric's interpretation of the 9 Blocks Cube was made of Maple, Walnut and Purple Heart with a much more manageable size of 7.3cm cube. As of the date of this post, there are still copies available at a very affordable US$37.

This past weekend, I played with Japanese puzzler/designer Kosh Arai's 3 Pentagons. The object of the puzzle is to lay the pentagon shaped (5 sided) pieces on a flat surface and form a symmetric shape.

For this puzzle, there were not one but three solutions and Koshi had in fact (generously) shown one of the symmetric shape solutions on the instructions that came with the puzzle. The task is figuring out the remaining two.

This is the 1st symmetrical shape solution provided by Koahi Arai

3 Pentagons was not only Koshi's IPP34 Exchange Puzzle but he also entered it for the Puzzle Design competition. His exchange version is finely made of an exotic (dark) wood (cocobolo?) and all the pieces precisely cut.

Unless you know the meaning of "symmetrical shape", you won't even know where to begin. There are typically two types of symmetrical shapes possible, one is mirror or line symmetry and the other is rotational symmetry. In most (if not all) of these symmetrical shape type puzzles, usually the object is to find a mirror/line symmetrical shape, which is the case here.

It took me several sessions over two days to find the two solutions. What makes the puzzle so difficult is that the three pieces are pretty similar in shape (and size) to each other and this sets up a huge number of possible combinations for joining the pieces side to side; yet only three symmetrical shapes exist. What an incredible design! I am very sure there is some complicated mathematics to all this but sorry folks, I am not capable of explaining any of it here...all I know is that I tried all sorts of ways to put the pieces together and eventually got the results I wanted.

Overall a very challenging puzzle indeed and a good thing that Koshi revealed one solution at least! If anyone wants to know the other two solution shapes, please contact me via my blog email.

If there is a Twelve Bow Ties #3, then there must also be a #2 in between #1 and #3. I had posted a write up about Twelve Bow Ties #1 last year and for the life of me, I don't recall having exchanged a #2....okay, maybe I did and its somewhere is my puzzle closet and I need to go find it.

TBT#3 is (apparently) the last of the TBT series. Designed and made by Wayne Daniel, this was Marti Reis' IPP36 Exchange Puzzle in Kyoto, Japan last year. The puzzle is about 7cm x 5cm x 5cm and shaped like two pyramids joined at their bases. Its actually an Octahedron, with eight faces, each an equilateral triangle shape.

My copy is made from what appears to be walnut and maple. Very well made with fine attention to the details and the very precise cuts of the notches and small pieces. Great work! Aesthetically a very pleasing puzzle to look at with the white colour accents on the faces.

The object is to take apart and re-assemble the puzzle, which actually splits up into 7 smaller pieces (the last two are either glued together or stuck somehow and I can't seem to take them apart). Each of the seven/eight pieces look identical but not quite. They are interlocked against one another and there is a certain sequence of sliding piece by piece out of the whole, one after another, in various directions. You can see from the photo how they come apart.

Unlike TBT#1, this version is much more difficult and if you are not careful with how you take them apart or you deliberately (and masochistically) scramble them after dis-assembly, putting the pieces back will almost guarantee a nightmare, as I discovered. Now, let me go and find #2....and complete the lot!

Here's a 2D packing puzzle that has occupied me for the last couple of evenings. The ZG#1 looks like your typical packing puzzle but comes with a twist...literally! Designed by Mineyuki Uyematsu (MINE) in 2013, it has a 3-unit piece anchored to the tray and rotates 360 degrees.

The four loose pieces look pretty "simple" and are precision laser cut to resemble the shape of "animals", hence the name. Don't know about you but I can (see) a chicken, snake, skunk and coyote! The tray is a 7x7 grid square.

There are two challenges here:-

#1 - Place all the three white pieces into the tray
#2 - Place any two pieces AND the red piece into the tray. (Problem-it doesn't say which two to use)

Simple looking but the puzzling is anything but simple. In fact it is damn challenging especially #2.

I didn't have too much problem with challenge #1 for this puzzle, partly because I design some 2D puzzles myself and have played with a number of them, and some with rather odd solutions (hint). However challenge #2 eluded me all the while. It is very difficult because you need to first find the two correct white pieces and then combine them with the red piece. Despite my many attempts at trying the (three) possible combinations to figure out which of the two white pieces to use, nothing worked. I could have been using the right white pieces all the while (and didn't know it) but still couldn't manage to solve the puzzle.

With the aid of Burr Tools (thank goodness this works), I was able to narrow down the two required pieces and from there arrived at the solution; something which I have no hesitation to admit that I wouldn't have been able to do on my own.

For packing puzzle lovers, definitely a must-get (unfortunately from what I can tell, its not available on MINE's site at the moment). When I bought it from MINE during the IPP in 2013, I remembered it was not expensive at all. So I would say its good value for money with plenty of puzzling; two challenges - the first easier (but probably will be hard for many, except seasoned packing puzzlers) and the second a real toughie!

Now here's an interesting series of packing puzzles that I received during the course of three puzzle exchanges since 2014.

These are none other than Henry Strout's creations. The only other puzzle I have from Henry is his nice Flower String Puzzle. From what I understand, Henry started doing this series of train packing puzzles for exchange since 2013 and will finish off his series in 2018. Apparently, he's got another car/tender and an engine to complete (if anyone has more accurate information or otherwise, please PM me).

These are fine works with wheels that spin, a simple coupler cum loop system to link train cars at both ends of each car and lids that are laser etched with the puzzle and IPP exchange details etc. The size of the train cars vary a bit but is pretty large and hefty with an average size of around 18cm x 10cm x 7cm. And all use just one type of wood (although I am not sure what it is).

All the puzzles bear the same style/theme...namely to pack anywhere between 8-10 irregular shaped block pieces into a train "car". Levels of difficulty also vary since each of the train cars or box contain different number of pieces and within each car, there are some protrusions or fixed restraining piece, which makes the puzzle that much harder.

Each of the train packing puzzles have been/will be either designed by Henry himself, or someone else. As I joined the Puzzle Exchange only in 2014, I missed out on the earlier first train puzzle. What I have are the train puzzles for the last three years:-

IPP34

Sphinks Cargo Car

Pack 6 pieces into the box

IPP35

Cutler Freight Car

Pack 10 pieces into the box

IPP36

Henry's Cargo Car

Pack 8 pieces into the box

In terms of difficulty, lets just say these are not so easy as they seem. In fact they are pretty challenging. The hardest I think would be the Cutler Freight Car with its 10 pieces and easiest is the Sphinks Cargo Car with only 6 pieces (I know because I was able to solve the latter) and in between Henry's Cargo Car.

A nice idea to create a series of related puzzles for exchange. And for anyone who enjoys trains and/or packing puzzles, this will be an interesting addition to your collection, that is if you can get the complete set.

Here's a nice sliding block puzzle that does not have a stratospheric number of moves. Its also a cute and colourful one and this was designed by Serhiy Grabarchuk, who is very well-known for his eye-catching and interesting looking sliding puzzle designs.

START POSITION

END POSITION

I have two of his other works which were reviewed earlier, his Sorter and One Fish Another Fish. I obtained the Sliding Arrow puzzle via a private exchange with fellow puzzler Dinair Namdarian, who also produced it. The puzzle is precision laser cut and well-made.

The Sliding Arrow measures about 14cm x 11cm and consists of a typical tray and 9 loose pieces. Unlike most sliding puzzles consisting of squares and rectangular shaped pieces, Serhiy had designed some of the pieces in the shape of a "bottle" and an "arrow". And this was fashioned into their shapes using translucent green acrylic for the bottle and yellow for the arrow. The "shaft" of the arrow is not another individual moving piece but cleverly recessed into the base of the tray.

The object is to get from the Start to the End positions as shown in the photos. Officially, the least number of moves to arrive at the final solution is 31. Not a lot compared to some other other sliding puzzles, for example, those from Minoru Abe. However, the moves are tricky and if you get the sequence wrong from the early stages, you will hit a dead end(s) and will have to re-arrange the pieces and begin all over again. This happened to me quite a number of times! Good thing most sliding puzzles have exposed pieces!

The Sliding Arrow is one of Serhiy Grabarchuk's more well-known designs and while the number of moves is not a lot, it is far more challenging than it appears.

The Karakuri Creation Group from Hakone, Japan is very well known for their fabulous and superb quality wooden puzzles and puzzle boxes. Equally well-known is that every year in the weeks leading up to Christmas, they will ship out their "Christmas Presents" to those who have joined the "Karakuri Club" and pre-ordered puzzles from a panel of designers, as early as the beginning of the year.

The puzzler selects the designer(s) of his choice, but would not know what sort of puzzle he/she will receive from their selected designer(s) until it arrives. It's a "surprise" to say the least! Not a cheap affair as well considering each puzzle is about US$100/- and there are usually an average of about 8 presents available per year. A full set will set you back about US$800/-.

For the rest of the year, the Karakuri Group designers release various designs and these puzzles can range anywhere from US$125/- to well over US$1,000/- a pop. Expensive would be somewhat of an understatement, but the design concept, theme, craftsmanship and attention to detail is simply incredible. Take a look around their site and you would know what I mean. From a puzzling perspective, some puzzles are pretty simple and provide little challenge for seasoned puzzlers but some designers like Hiroshi Iwahara create extremely challenging pieces.

Aside from exquisitely crafted puzzles, Karakuri also retails wooden puzzle kits. The one shown here is the Urashima's Box, which I purchased during IPP33 in Tokyo several years ago. I have had it for quite a while and totally forgotten about it until recently.

The kid is made of plywood and while there is nothing exotic about plywood, the pieces are very well cut and precise. It has even got a nice woody scent to it. It costs only about 2,000 Yen (US$17.50) but the quality is very good.

The kit comes un-assembled of course and this one has 16 pieces including the string. When fully assembled, it is a trick opening box. everything you need is in the kit except glue and here I used an inexpensive wood glue called Wessbond White Glue which dried quickly and gave good results. Smears and stains were easily cleaned off with a damp tissue. There is no need to go for epoxy and other fancy glues for this sort of work.

Although the instructions are all in Japanese, the diagrams are easy enough to understand for the assembly of the box and no translation needed. It took me no more than half an hour or so to glue all the parts together and another 6-7 hours or so for the glue to dry properly. The finished product was strong, sturdy and nice to look at, especially with the ribbon tied.

I don't think I need to explain the object of the box here and from photos i think you can quite guess how the mechanics of the puzzle works. So if you can't afford or don't want to shell out the dollars for the ala carte puzzles on their Michelin-starred menu, you can still own a Karakuri puzzle...get a kit! They are great fun and relatively easy to build and will astound your non-puzzling friends for sure!

Don't be mistaken. This is not about one of the most evil men in modern history, but rather the name of Rik van Grol's IPP35 Exchange Puzzle in Ottawa, Canada. Before anyone has anything to comment about the choice of name, here's Rik's explanation in his notes accompanying the puzzle:-

1. "Bin", which is short for "binary", refers to the solution method.
2. "Laden" is Dutch for drawer or tray
3. "Bin Laden" is the name of someone considered by many as the personification of the the devil. In a "devilish" streak, I took the liberty to ignore the "rules" of a true binary puzzle
4. "Too" sounds like "two" and means my second Bin Laden puzzle is equally "devilish"

(NB: Rik had designed the first Bin Laden puzzle for his exchange in Boston in 2006, reviewed by Oli Sovary-Sooshere)

First off, the BLT is long and rectangular and entirely laser cut and glued together from layers of wood. It measures about 16.5cm x 5.5cm x 4.5cm. It's a secret opening box with 5 small drawers or trays. Standing vertically, it looks like a miniature cabinet with short legs to boot.

The object of the BLT is to "remove all five dice from their trays and close all the trays again". As Rik has mentioned in his notes, he has deviated away from a true binary puzzle design. For those in the dark about binary and such, check out Goetz Schwandtner's article on binary/n'ary puzzles.

I have played with a number of n'ary type puzzles before such as Cross & Crown 2013, Numlock and Schloss 250 so I kinda knew what to expect and how to go about solving. Simply put, there is a repeated sequence of moves that have to be made to arrive at the final solution. The challenge is to firstly discover that sequence AND then to remember it; one misstep and you are almost always guaranteed to go back to square one....in fact you might get stuck and not even able to start from beginning again.

Solving consist of pulling and pushing the individual drawers in and out of the box. The top and bottom panels are also able to move upwards and downwards (about 0.4cm) within certain limits and these affect the movements of the drawers. So in total you got 7 moving pieces (with mechanisms all hidden from view) to navigate inside the box.

I started off noting down on paper the early moves and at first there appeared to be some tangible sequence but after about nine moves, the sequence went out the window. What happened the next 45 mins or so was more trial and error trying to get the drawers opened. Each of the drawers do not either fully extend or retract but rather have various stop positions which adds to the difficulty. Proper alignment is also crucial, otherwise you might miss a move on one of the drawers. One by one I managed to get all the 5 dice out, but with a lot of effort. And thereafter in my attempt to repeat the moves, I got mixed up and it was another trial and error session before I managed to finally close all the drawers, and re-open them again. However, I just couldn't get the lowest drawer to open fully like I did the first time, so I was not able to return the 5th dice to it.

I will have to ask Rik for the solution or wait until the IPP35 Exchange Puzzle Booklet is out to find out how to solve the BLT in the fewest moves possible. Like Rik had pointed out, this isn't a true binary puzzle so as far as I could tell, there was no "repeated sequence" to be found and the puzzle behaved just like a burr, only thing is that the BLT's moves are hidden inside the box.

For a trick opening box, this is a great concept with the use of drawers and a "pseudo-binary" design to ensure a large number of moves to fully solve the puzzle. But the BLT is anything but short of very challenging and certainly something very different from the usual high level burrs.

Ray Stanton is well-known for his series of co-ordinate motion "pseudo-burr" puzzles, burrs that look as such but do not behave like a typical burr during the solve.

The Slideways Cube from Ray, which was also his IPP35 Exchange Puzzle is no exception. Physically it looks like an ordinary cube (interlocking) puzzle. It measures about 5.5cm on all sides and manufactured by Pelikan Puzzles out of Mahogany and Cherry. Consisting of just three pieces, each piece is a combination of straight and slanted cut smaller cubes/rectangles glued together. Quality, fit and finish is very good.

The object is to take apart the three pieces and re-assemble. Like Ray's previous puzzles of a similar nature such as the Quad Slideways Burr, Double Slideways Burr, one of the key challenges is to first discover how the puzzle would come apart. Then comes which part/area of the puzzle to press/pull in order to separate the pieces. Pelikan has done such a great job of construction that it took me quite a while to find the joint lines, which are so well hidden, where the three pieces meet; ie the starting point. The fit is snug (made more so by the high Singapore humidity) so it took some effort (and dehumidifying) to slowly ease the pieces outwards away from each other. It comes to a point where the pieces would release themselves and come apart.

Unlike the two other puzzles mentioned, the re-assembly for the Slideways Cube is not as difficult since the final shape to achieve is a cube and the cherry/mahogany combination has a surface pattern which also gives some indication how to pieces are to end up together. Moreover, with just three pieces, it is very manageable with just two hands. No clumsiness of handling here, unlike the Double Slideways Burr which had six pieces. (Hint: always good to photograph the puzzle before you start....and during solve...it will save you a lot of headache later). I have decided not to show the puzzle in mid-solve as this gives away too much. As of the date of this post, Pelikan does not list the Slideways Cube on their site, so I guess there is none available for sale. Not sure of Ray has any spare copies tho'

[Edit 26 March : John Devost has a copy available here]

This was both a fun and challenging puzzle that I have been playing with during the course of this week. Growing Triangle is the design of Andreas Rover, the man behind Burr Tools, a free software programme that has brought relief to thousands of frustrated puzzlers (myself included) and changed the course of history for designing and solving burr (and other) puzzle designs.

I obtained Growing Triangle from Andreas during the Puzzle Exchange at IPP35 in Canada two years ago. In Andrea's own words....

"This puzzle is inspired by "London Squares" which was designed by Li Zhunyou and exchanged by James Kerley at IPP34. Although I very much enjoyed the puzzle I spotted some "usability problems" and I want to fix with this design"

Growing Triangle is precision laser cut from 6mm clear acrylic< Made by Mr Puzzle, it consist of 12 irregular shaped pieces. Each of the pieces are also etched with markings to indicate the number of triangular units within. The finishing touches include a nice red drawstring pouch.

There are 11 challenges to the puzzle, simplest being to take 2 of the 12 pieces and form an isosceles triangle of 4 units length per side. Then take 3 pieces and form a triangle of 5 units per side, 4 pieces to form triangle of 6 units per side until all 12 pieces are used to form the largest triangle of 14 units length per side. Each challenge offers a unique solution and as you would imagine, moving from 2 to 12 pieces becomes progressively harder and painful. I have shown just the first two solutions here as an illustration of what this puzzle is about.

The first several challenges are not difficult and it is rather obvious which pieces are needed for the solve. From my personal standpoint it becomes "exponentially" difficult once you go past 5 pieces. The instructions do not tell you which of the 2, 3, 4, 5 and so on... pieces to use. You need to figure this out for yourself! But it does not require any form of random selection...rather if you study the puzzle sizes from the beginning, from 2 to 3 to 4 unit lengths and beyond, you will realise there is a trick to finding the area size of the next required piece as your triangle enlarges (grows).

So far I have grown my triangle to 11 units length per side using 9 of the 12 pieces. But I have since remained stuck at this level (but I am still trying).

Oh, and did I mention that you can use Burr Tools to solve all 11 challenges of the puzzle? :-)

American Eitan Cher's IPP36 Exchange Puzzle, Pack Your Passport is IMHO one of the nicest looking 2D packing puzzles I have come across, and believe me, I have quite a large number in my collection, and none of them come close!

This is a meticulously crafted puzzle that measures 13cm x 9.5cm x 1.7cm, about the size of a real passport. It consists of a number of layers of acrylic glued together to form a two-page "passport" with the covers held together by rubber bands. The puzzle including the 10 irregular pieces that come with it are precision laser cut and the entire package smacks of high quality. As I understand, Eitan has access to a number of laser cutting machines at his disposal, hence his ability to ensure quality control over the final product.

Not only is the puzzle beautiful to look at and feel, the design concept of the puzzle also deserves commendation. IPP35 was hosted in Canada and IPP36 in Japan. Pack Your Passport was designed by Rex Perez of the Philippines and aligns itself very well thematically. On the first page of the "passport" is the Canadian flag with a cut-out of a maple leaf; detach and flip it over and you see the Japanese flag with a cut-out of the sun. the second layer stores the 10 loose pieces which are neatly stored in their own slots.

The goals are simple and clear, use all 10 pieces to form the maple leaf of the Canadian flag and the second challenge is to use the same 10 pieces to form the sun of the Japanese flag. Believe me, both challenges are very difficult, since there are 10 pieces involved and in the case of the Japanese flag, there is only one solution. Quite a design feat, I might add.

I struggled with the Canadian flag for a couple of days before I decided I needed help and promptly shot a message to Rex for a clue. Quick was his reply (he too couldn't solve it sometimes!) and he indicated to me where one of the 10 pieces was suppose to fit within the cut-out. With this, I was able to solve the puzzle during the next hour or so. Next I tried the Japanese flag but as of the date of this post, I have still not solve this one. Still waiting for Rex to forward a clue.

Between the two challenges, the Canadian flag is the easier one, since careful observation will reveal that there are a couple of pieces that can only fit (or not) in certain places within the cut-out and this reduces the level of difficulty somewhat, but perhaps still not enough!

For packing puzzle lovers that also demand top-notch quality, Pack Your Passport is a must-have. From what I can tell, it is commercially available from http://www.puzzle-shop.de.

Its been a while since I last played with a Yavuz Demirhan puzzle. The last one was the Quadrant 1 reviewed over a year and a half ago. This time, Yavuz's design is the Ovolo, which was also the Exchange Puzzle of Brian Young at last year's IPP36 in Kyoto, Japan.

This is a rather nice and unusual looking 8 piece interlocking puzzle, consisting of 6 board pieces cut from 10mm acrylic and two other wooden pieces (made fromQueensland Blackbean) each comprising of three sticks glued together - like in the form of the X, Y and Z axes (see photo).

Dimensionally the size of the assembled puzzle is 7cm x 7cm x 7cm. Construction fit and finish from Brian is as usual, impeccable and the combo of acrylic and wood gives the puzzle a rather interesting and striking appearance.

The object of course is to dis-assemble the puzzle and then -reassemble it. Taking the puzzle apart was not too difficult for me and it took just a bit of experimentation to find out how the pieces moved. I took my time with the Ovolo, wanting to commit the moves to memory so that I could (hopefully) re-assemble the thing without any help later. Took me somewhere around 5-6 moves and I got the first piece out. The rest came apart quite easily thereafter.

As Brian says on his website which retails the Ovolo for A$40/-..."this puzzle is not so difficult to take apart. But mix up the pieces, walk away and forget about them, come back later and you'll find it quite difficult to put back together. There are many false moves and dead ends; 42 false assemblies and just ONE level 5 solution.

Brian is absolutely spot on about the ease of taking the puzzle apart...but unfortunately I didn't even have to "mix up the pieces, walk away and forget about them..."; in fact while I immediately tried to put everything together hoping my memory of the moves was still fresh....I couldn't! Somehow I got the orientation of the pieces wrong and ended up with the false assemblies. Visually, the clear acrylic was no help either and in fact added to the confusion and difficulty (that's why perhaps acrylic was used).

Finally after several days, I threw in the towel and emailed Brian/Sue for the solution. The assembly process didn't quite seem the exact opposite of the way I had taken apart the pieces...but no complaints...I got the Ovolo back to its original state. Nice attractive looking puzzle with fairly simple looking pieces. Don't let the level 5.2.2.1.1.3 solution fool you. Relatively easy to disassemble but putting everything back together can be a real nightmare!

I have never been a huge fan of shape forming puzzles. But after I played with Emrehan Halici's Four Triangles Five Shapes, and more recently Andrea Rover's Growing Triangle, this sort of puzzles, plus the "form-a-symmetrical shape" ones have gotten more of my attention (and liking). I have also recently designed something along similar lines and hopefully will be able to showcase it at IPP37 this coming August.

Square & Equilateral Triangle (SET) is Halici's IPP36 Exchange Puzzle. There are two goals here; use the five irregular shaped pieces to form a square and the same five pieces to form an equilateral triangle (a triangle with three sides of equal length).

It makes me wonder about the genius of Turkish Halici to be able to come up with a design for two different (and symmetrical) shapes using the same pieces; incredible! Unlike his Four Triangles Five Shapes which I failed dismally, I am proud to say that I managed to solve SET without any help, although it took me a number of short puzzling sessions over several days.

I managed to solve the square within a matter of minutes, but the equilateral triangle took about fifteen times longer...it simply eluded me despite my many attempts to try the different combination of putting the five pieces side by side. Finally the A-ha moment arrived one day during a lunch time break.

[Edit 20 April 2017 - Stanislav Knot has come up with an additional 9 different shapes using the 5 pieces. Thanks Stan!]

For folks who are into this sort of puzzles, the SET has just the "right level of difficulty" for an exchange puzzle; one relatively easy goal to get the juices going and a second much tougher challenge. Anyone keen to see the two solutions please PM me here.

Impossible object puzzles never cease to amaze me. They are really in a category of their own and generally, among mechanical puzzles, come far and few in between. Primarily because they are so hard to produce or "put together" into an impossible object.

I always love it when I am able to get my hands on one. I have several really cool impossible objects in my collection including some "seemingly impossible" ones like the Puzzle Jam and 4 Street Elbows and the more "solvable" types like the Exchange Washington DC, Smiley In A Bottle and Coke Bottle #1.

This one here is the design and handiwork of Hiroaki Namba, who also gave us the Double Cast Puzzle Hook reviewed earlier. This impossible object was Mr Namba's IPP35 Exchange Puzzle in Ottawa, Canada in 2015.

It consist of an ordinary bottle with a standard Hanayama Cast Vortex inside. I have never played with a Cast Vortex so can't comment on it, but it's rated 5 stars on the difficulty level quotient (meaning it's really very difficult) by Hanayama. And judging by the video solutions posted on YouTube, it looks extremely challenging to take apart just on its own, not to mention extracting it from a bottle.

No doubt of course Mr Namba would have found a way to twist and solve the Vortex into the bottle, and probably doing it in a very elegant way too! Inside the bottle, the Vortex cannot be taken out as it is obstructed by the narrow mouth of the bottle and the only way it seems would be to (partially) disengage the three parts before extraction.

"Loopy" in the English language means "mad or silly" or "having many loops". In the case of the Loopy Box puzzle, it is hardly the former (given its very difficult challenge quotient) but certainly the latter, as I shall try to describe below.

First off, its credentials; designed by Jean-Claude Constantin (now I haven't played with a JCC design for a long time, the last one in my hands was over 3 years ago; the Lock 250). It is also manufactured by him out of laser cut wood with the sides and bottom glued/screwed together to form a box. This puzzle was also Allard Walker's IPP35 Exchange Puzzle in Canada in 2015.

The puzzle measures about 11cm x 10.5cm x 7.5cm and is essentially a box with a lid that is "locked" in place by a piece of thick rope (see photo). Quality and construction is very good, typical of the JCC standard. The object is to open the lid and solve a second puzzle inside, a modified Hanayama Cast Claw that has an extra U-shaped piece linking the two claws.

In the last few years Allard Walker has had this habit of making puzzle exchangers work really hard by exchanging not one but two puzzles at the same time (usually one contained inside the other; see Conjuring Conundrum and Baffling Bolted Book). Well, he is a gentleman of means and can afford it... and I for one is certainly not complaining, since I am getting two separate puzzles from him in one exchange! The second challenge after the box is open is to take apart the Cast Devil.

Now back to the puzzle; as one can observe, the only sensible way of opening the lid would be to remove the length of thick rope. But unfortunately this is hardly that simple as I found out. The rope passes through a hole in a vertical slat and holds the lid down. The rope itself is attached in some way to a dial (and what's underneath the numbers and inside can't be seen clearly if at all, I tried shining a torch but it didn't help). It would be obvious that the dial (which can turn in both directions) has something to do with the rope's release.

I spent an estimated three to four days trying to disentangle and release the rope and even read Kevin Sadler's experience with the Loopy Box hoping to find some clues. But Kevin, like all good puzzle bloggers gave little clues on his blog and his photos didn't indicate anything of use either. Nothing worked and after some more trying I gave up and asked Kevin for a clue. He said he was too busy during that time and he also had to find his copy from his collection of several thousand puzzles. Not forgetting, he is a busy doctor and also. has Mrs S (which I had the privilege of meeting at IPP34 in London) to spend time with too!), He did mention that it involved quite a bit of dexterity and that was all I had to go on. I left the Loopy Box alone. Fast forward to the present after several weeks, and I had a go at it again, but still no luck. After trying incessantly, I contacted Allard for help this time. Now why did't I contact Allard in the first place back then??

When I saw the solution from Allard I said to myself - damn!, now why didn't I think of it? The way to remove the rope is pretty clever (I am sure those disentanglement puzzle experts would have quite quickly figured it out) but the physical execution of the correct technique is more than fairly difficult (even when you know exactly what needs to be done). Everything was pretty fiddly and my only criticism is that perhaps the dial and other parts could have been made larger to accommodate bigger fingers! After more than several minutes, I finally freed the rope and opened the lid to face the second puzzle!

Nope - I didn't go on to the modified Cast Devil and decided I will leave it for another day. For all those interested, the Loopy Box is available from Puzzle Master in Canada for CA$52.99 and from Puzzle Shop in Germany for 35 Euros.

I have had several Dick Hess puzzles in my collection for some time now and he has designed and produced quite a number including both packing, sliding block and entanglement ones. I thought I would start off with something of his that is more manageable and the 3/4 Pack Puzzle fits the bill just right.

The 3/4 Pack Puzzle was Dick's IPP36 exchange puzzle in Kyoto last year. Its a 2D tray packing puzzle with six 3/4 discs. Manufactured by Walt Hoppe, it is made from laser cut Cherry wood and measures about 12.7cm x 9cm x 0.9cm. The tray and pieces are precision cut with tight tolerances. It even has a slot for one of discs for ease of storage when not in play

Typically for puzzles like this, where the fit is just right, I would place it in a dry box to make sure there is no expansion of the pieces due to the high humidity, which is what I did. One never knows if the inability to solve could have been due to expanded pieces which can't fit where it should.

The object is to place all six 3/4 discs flat into the square cavity. The puzzle comes with the solution sheet which shows that there are actually 8 ways to pack the pieces in. This explains why I didn't have too much trouble with this packing puzzle! But of the 8 ways (plus flipped pieces), only two are optimum (best) solutions and the rest go in descending order thereafter from 2nd, 3rd, 4th and 5th best solutions. I am proud to say my first attempt was actually one of the two "best" solutions!

The 3/4 Pack Puzzle is not too difficult and this is one of those packing puzzles that you can lay out all the pieces in the tray and slowly manipulate the pieces bit by bit to ensure every piece will fit inside. However, aside from the challenge perspective, I guess what's significant is also the math behind the design and the very precise manufacture of each and every copy to ensure that the puzzle works properly as intended. For those keen on the 3/4 Pack Puzzle or other Dick Hess puzzles, please PM me via my blog site email.

This cute and quirky glass jar containing colourful clogs comes courtesy of Rob Hegge, who designed and produced the Dutch Souvenir Pack (DSP) as his PP36 exchange puzzle.

The Dutch wooden clogs or Klompen are from the Netherlands and many are sold as tourist souvenirs. The jar is an ordinary looking glass jar with an airtight lid that locks; the type where you can fill it with jellybeans for kids. As far as the clogs are concerned, they appear to be those that can be easily bought off the street.

The DSP is a "3D" packing puzzle, if I can use such a definition and comes with 4 challenges, ranging from relatively easy to impossible:-

1. after removing the clogs and ball, place all 3 pairs of clogs into the bottle;
2. Same as above but close the lid
3. Same as 2 above but all the clogs must be below the lowest metal ring of the locking mechanism.
4. Same as 2 but include the rubber ball inside.

I solved challenges 1 to 3 but had absolutely no luck with 4. #3 was a tad more difficult since the the clogs had to occupy the correct position inside the jar below the lowest ring; hence some serious packing was needed, bu still manageable.

#4 was quite impossible for me! In fact it does look quite like an impossible object. I shall wait for the solution to appear in the IPP36 souvenir booklet to find out how to pack the ball in with the clogs.

As far as packing puzzles go, this one wins the prize for originality and aesthetics... and very appropriate as a (Dutch) souvenir, which doubles as a nice puzzle too!

I am really hopeless at disentanglement wire puzzles, that's why I rarely, if ever buy any for my collection. However, now and again, I do get a couple during the IPP Puzzle Exchange. Occasionally I would look at the wire puzzles I have and decide if I should give one a go.

Well, Dick Hess' IPP34 exchange puzzle, Keys To The Kingdom caught my eye. And moreover, it didn't look that complicated and entangled, unlike some of the other string/wire puzzles I have come across.

The Keys has not one but two (really four smaller separate) challenges. The first two consist of removing the two "key" from the upper squarish loop and the second is to join both keys into the lower circular loop.

Like many wire puzzles, the Keys at the beginning look like a bit of a jumbled mess impossible to take apart. But you know physically it is doable. But to my (pleasant) surprise, I actually managed to solve the first challenge of removing the two keys frustration free! Of course being lousy and inexperienced at such puzzles, I am am sure I took much longer than a seasoned wire puzzle expert. I was beginning to like wire puzzles already.

However, what took me about 20 minutes to solve the first challenge, I failed to replicate to the second task. Sadly I spend a good part of a whole afternoon without success. Finally I threw in the towel and referred to Dick's accompanying solution. However, despite the text and diagrams presented, which admittedly I did not fully quite comprehend, I still couldn't figure out how to link both keys to the bottom loop. I will have to drop Dick a note to ask for a better explanation.

No doubt I didn't solve the Keys completely, I still think it is a good wire puzzle to have because it not only provides two challenges but also allows a puzzler to have a couple of A-ha moments for the (easier) first challenge.

Steward Coffin's designs are typically not known to be easy and my puzzle of choice this weekend was no different.In fact it is probably one of the harder ones I have played with, considering the amount of time it took me to solve. This puzzle was Jerry Slocum's IPP34 Exchange Puzzle called "Checking In" and its Coffin's design #223.

Checking In was made by Brian Young of Mr Puzzle and comprises of Western Australian Jarrah for the tray and a combo of Jarrah and Queensland Silver Ash for the eight pieces. The puzzle measures about 10cm x 10cm x 1.5cm. According to Brian, this design has never been made before so its the first time design #223 has been produced. As usual, quality and construction is very good and the pieces with its two-tone colours looks fabulous.

The puzzle comes "semi-solved" and the goal is to fit one of the pieces packaged at the bottom of the frame flat into the tray together with the rest of the other seven pieces. Not only that but to also form a checkerboard pattern as well. Each of the eight pieces consist of dark and light squares and half squares (triangles) glued together. One look and it is obvious right from beginning that this one wasn't going to be easy. The pieces don't look like they can all fit into the tray. And the fact that its eight pieces already ups the the difficulty quotient by a few notches.

I spent around two hours or so over several sessions trying to figure this one out. At first, random sort of packing, but usually this won't work when there are a large number of pieces. Then I tried logical deduction/reasoning, which I would say helps to some extent for this puzzle. Many a times, it was always the last one or two pieces that couldn't fit. But eventually the a-ha moment came when I adjusted the last few pieces and the tray accepted the last piece nicely...and in a checker board pattern too! A rather "interesting" solution I might add!

Not at all easy but not unduly frustrating either...although I would imagine that those who don't often play with packing puzzles could spend hours on Checking In and get no where. Mr Puzzle rates it a 6/10 for difficulty but I think it deserves a 6.5 or 7. If you are into packing puzzles (and given this is a Coffin design which is not easily available), Checking In should be on your must-have list. Available only from Mr Puzzle at a price of A$50/-

For anyone who might want to take a look at the solution, please PM me via my blog email here.

The 'Tel Arad' is perhaps one of the more unusual puzzles I have come across. Certainly its a category of puzzles you don't see everyday, although it does remind me of the snake cube/snake man type puzzle.

This is the brainchild and creation of Yael Meron (Ms) from Israel, with whom I had to pleasure of exchanging puzzles with at IPP34 in London in 2014.

The name of the puzzle (according to Yael) "is inspired by the ancient Israelite city of Arad, located west of the Dead Sea. The site is a Tel, which is a type of archaeological mound created by layers of human settlements over centuries" For more info on Tel Arad, click here.

The puzzle which is produced by Yael herself consist of 9 acrylic squares (3 of each size) which is bound together by bands. The object is to stack the squares, one inside another in three layers. The puzzle in the solved state measures 5cm x 5cm x 2cm. Now these are not rubber bands that stretch, otherwise the puzzle won't be much of challenge but rather the bands are 'non-stretchable" and they hold the squares together (quite tightly) as shown in the photo.

The starting position is as shown per the accompanying instructions (and in the photo of the puzzle) and the puzzler must stack the squares as per the solved position. Stacking the squares would obviously require the folding of one square over another, the smaller squares going into the bigger ones and so on. Simple to say, but the puzzle is actually much more difficult than it looks. Initially I was pretty gentle with the folding and twisting as I was not sure how much stress the bands can withstand without breaking. After a bit of fiddling, I realised that if you don't apply brute force, the bands are actually quite strong.

Random trying here and there may help but some logical thinking will help you solve the puzzle faster and reduce the chances of wear and possible tear of the bands.

Definitely a rather unusual puzzle indeed and one which results in an elegant solution that surprises, and also no undue force whatsoever is needed (although wriggling is permitted to turn the squares held by the bands). The difficulty level is just right for an exchange puzzle.

As far as I can tell, this puzzle being a private exchange puzzle, is not available anywhere except perhaps from the designer. PM me if anyone is interested to acquire one and I will link you up with Yael Meron.

9 Blocks Box & 9 Blocks Cube

3 Pentagons

Twelve Bow Ties 3

ZooLogical Garden #1

Trainspotting

Sliding Arrow Through The Bottle

Urashima's Box

Bin Laden Too

Slideways Cube

Growing Triangle - Growing Pain

Pack Your Passport

Ovolo

Square & Equilateral Triangle

Cast Puzzle Vortex In A Bottle

Loopy Box

The 3/4 Pack Puzzle

Dutch Souvenir Pack

Keys To The Kingdom

Checking In

Tel Arad