3 Pentagons

This past weekend, I played with Japanese puzzler/designer Koshi 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.

9 Blocks Box & 9 Blocks Cube

Update 23 October 2017 - Dear Reader, please check out my new puzzle blog and e-store at http://mechanical-puzzles.com

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.

Haleslock 2

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

This is my 400th post! How time has flown by. And what better puzzle to write about than one coming from a really talented puzzle designer, Shane Hales from the UK. 

Shane started designing puzzles several years ago and I have had the good fortune to receive as gifts two of his very limited edition puzzles, first The Circle and later Turn The Plug. His puzzles are limited edition either because he produces only several of a particular design or he gifts them to friends. Until recently, Shane did not sell any but only gifted his puzzles to the lucky few. I am one of them lucky ones who got a Haleslock 2 as a Christmas present!

Recently Shane has progressed to producing puzzle locks. His works are not designed from ground up, example, in the style of Rainer Popp, meaning to say, he designs and produces a puzzle that looks like a lock, Instead, he goes the Dan Feldman way, where he uses existing commercial padlocks on the market and modifies them into a puzzle/trick lock. Shane's locks, the Haleslock 1 and Haleslock 2 were made available for a charity auction and sale respectively on his puzzle site but unfortunately for puzzlers, his Haleslock 2 are all sold out.

So coming back to the Haleslock 2...what is it like as a puzzle? Well, as I have alluded to, it is a typical looking padlock from a brand called Squire. The lock comes with two keys (one without any teeth as can be seen from the photo) and attached by a rather long chain to the shackle. The object of course is to un-shackle the lock.

I had read Allard Walker's blog post on how he had solved the Haleslock 2 and commented that it was "not extremely complex or complicated". For me personally, this couldn't have been further from the truth! I had solved Shane's previous puzzles, The Circle and Turn The Plug without too much frustration and without help, but for some (strange) reason, I could not solve the Haleslock 2 even after multiple sessions of playing over a number of days. Something was eluding me to the point I decided to ask Shane for not one, but two clues before I managed to figure out the first move...and the Hales Lock has four moves to free the shackle.

After the first move was done, everything else became easy and I released the shackle without a cinch. For me, the solution for the Haleslock 2 was totally unexpected. The "trick" (no pun intended) of the Haleslock 2 is IMHO a really a good one not easy to discover. With hindsight, I realized that I had missed something right at the beginning that I shouldn't have. Overall a great trick lock with an original and different idea/concept. Good work Shane!

Cast Infinity

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

A very Happy New Year to everyone! This is my first post for 2017.

This weekend's puzzle was Vesa Timonen's Cast Infinity produced by Hanayama. In case you do not know Messr. Timonen, he has designed many puzzles and a number for Hanayama such as the Cast Loop, Square, Cylinder and Donuts.  A number of them award winning, including his non-Cast Symmetrick.

The Infinity comes with a shiny surface and is very well made (of zinc alloy). Tough and heavy. Generally I would prefer a matt to gloss surface for metal puzzles but in this instance, the shininess actually works pretty well and accentuates the curves of the Infinity. IMHO, it's one of the more beautiful and aesthetically pleasing puzzles around.

Size wise, its measures roughly about 5.3cm x 3.2cm x 1.7cm and large enough to be handled quite comfortably.

The object here is to remove the two inner circular pieces from the "8" shaped cage (the Greek symbol for Infinity).

From the puzzling aspect, this is not an easy puzzle. Hanayama rates it at a level 6 stars; ie most difficult in the Hanayama range. But with only two moving pieces, its not excruciatingly difficult and I would rate it rather at about 5 stars. Both pieces rotate within their respective housings inside the cage, but they are interlocked against each other via a series of notches on the pieces as well as the inside of the cage itself.  At any one time, only one of the two pieces will move in one particular direction. To solve the puzzle, the pieces need to be rotated in both clockwise and counter clockwise manner (as well as upwards and downwards) and there is a sort of sequence to this, otherwise one or the other piece would simply find a dead end.

In some ways, I kinda have the feeling that the Cast Infinity is almost a bit like a "N-ary puzzle" where there is a series of repeated moves, but technically I don't think this is the case [Edit 8 Jan 2017: Puzzler Michel van Ipenburg has confirmed to me that the Infinity is indeed a N-ary puzzle]. Other puzzles with a similar "style" that came to my mind when I was playing with the Infinity are the circular type burrs designed by Derek Bosch such as the Helical Burr, Pole Dancers and Vapors , where you manipulate two main opposing interlocking pieces in a particular sequence to disassemble. For lack of anything else, I guess you can call it a flat(ish) burr.

Overall the Infinity is great puzzle and I was rather surprise that I took less than 20 mins to disassemble the pieces and just a tad longer to put everything together again, the latter in the reverse order, but more difficult. Once you have gotten used to the moves, its fairly repeatable also. And coming from Hanayama, you can be assured of decent quality and value for money pricing.