Wednesday, 27 May 2015

A couple o’ Karakuris

One of the col things about being a member of the Karakuri Club (apart from the Christmas presents!) is that you get notified of all of their new offerings and often their newest puzzles are only available to Club members.
Recently I picked up a couple of rather neat new boxes from them…and a one of their work kits that I’ve been meaning to try out for absolute ages (although that came via Satomi at CU-Japan).
Akio Kamei’s Rotary Box II is a big solid hunk of puzzle box. It’s not light and you’d be forgiven for thinking that it either didn’t have a lot of space inside it, or it had quite a bit of gubbins in there…
It looks pretty plain, if rather neatly finished off on the outside – the rounded edges give it a nice feel with the two halves in contrasting woods giving you a very clear steer toward how the box is likely to come apart – either that, or a very strong piece of misdirection!
Early experimentation with the box didn’t yield much at all, in fact it’s all rather securely locked up until you try something a bit unusual, and a bit bold, and soon enough you find the first of two compartments…finding the second is a bit more tricky and as with quite a few of these puzzles, if you didn’t know there was another, you might completely overlook the existence of a second compartment […and that’s why I put a couple of Japanese coins in the second compartment…].
Once you do find it, you’ll enjoy how opening each of the compartments is linked – yet so easy to overlook.
It’s quite an unusual Japanese puzzle box, not overly complicated but reasonably satisfying. 

Next up is the latest offering from Hideaki Kawashima, enigmatically titled Half (J) – I’m afraid I haven’t worked out the significance of the name yet. This one appears to be made up of four interlocking puzzle pieces in contrasting colours – with no obvious way for them to come apart. 
 A little experimentation will generally result in a rather magical movement beginning – and once it does, it dawns on you that that would have been the only way that things could have moved without contradicting one of Zeno’s paradoxes, or Pauli’s Exclusion Principle, depending on what you read. I just loved that motion and really enjoyed the second part of it… which then reveals the two compartments, right where you’d expect them to be. 
As far as move counts go, this box is probably about as low as you can get, but the movement is really delightful and surprising, to the extent that I’ve found myself randomly reaching for it on the desk and working it backwards and forwards just to put a smile on my face – it works every time! 
Love it!

Last up is a Karakuri work kit called the Ninja Box. I chose this one because it’s only available in kit form, so unless you build one for yourself, you can’t have one… 
A couple of my puzzling mates have tried the Karakuri kits and enjoyed putting them together so I reckoned it was about time that I joined their ranks… I ordered one from Satomi and the little bag of wooden bits duly arrived along with a wonderfully detailed set of instructions – in Japanese. 
Now I realise this will come as a surprise, but I’m not fluent in Japanese – and I certainly cannot read Kanji (or any other form of Japanese script for that matter!). Have no fear, the instructions come with some wonderfully explicit diagrams – that show all the details perfectly, including where to put the glue so that you don’t gum up the internals… while I might be missing some of the nuances of the instructions, you can definitely make do with just the pictures!

I cleared a small spot on the desk over the weekend and set about assembling the little guy – the instructions really are wonderfully clear (even without understanding the text!). The pieces are all perfectly cut and notched so they go together really easily and a bit of masking tape holds things together rather effectively. 
I attacked it in a few spurts, assembling various bits and taping them up before going back to my current second job, aka The Book.  A few hours between each sub-assembly allows the glue to dry properly before adding the next layer and repeating the whole cycle. 
 A couple of minutes with a bit of sandpaper removed any extraneous traces of glue along the way, but apart from that, the kit literally just needs gluing together… the Karakuri guys have done all the hard work for you getting the bits all cut perfectly to size.
I rather enjoyed putting it together and I now have a neat little Ninja Box to add to the Karakuris in the cabinet…sure it’s not quite as pretty as their productions, but I made it. :-)
If you are thinking of having a go at one of their kits, go for it – the pieces are all spot-on and the design is pretty much self-jigging so you’ll end up with a box that works, even if you have a few too many left thumbs.

Sunday, 17 May 2015

Unusual stuff from Eric...

Eric Fuller has found some rather unusual looking puzzles to make recently – you can read about his Chicken on Jerry’s blog over here, and Kevin’s over here… no sense me telling you about it as well…

There have been a few other rather unusual and intriguing offerings that don’t look like poultry, take Tom Jolly’s Bundle of Sticks for instance… made to look like a – you guessed it – bundle of sticks. This assembly / disassembly puzzle consists of four sticks with some rather well-placed protrusions (thorns perhaps?) that interfere with the ring that holds the bundle together. 

When you start this puzzle those thorns are arranged in a neat semi-symmetrical pattern around the sticks with the ring smack bang in the centre. 

Removing the first piece is not a challenge – it’s a key-piece and simply slides out under the force of gravity… removing the next piece is far more interesting!  That takes 13 moves… and even removing the second last piece takes another six moves. 

With the simple ring around the centre all of the pieces are pretty much in view all of the time, so you can plan a route to get things out of the way. A couple of the pieces have caps on their ends which cuts down on the possibilities for movement in a few of the orientations, but even still, working out how to align the pieces in order to make progress isn’t a horrible challenge in spite of the puzzle’s level. 

There are one or two potential dead-ends, but they don’t trap you for long…
I really enjoyed this puzzle – it’s a great design from Tom and Eric’s done a lovely job of bringing it to life in holly and wenge, so it looks brilliant! […and rather unusually, as I’m writing this, there are still five copies available for sale!]

Next up is a variant on a puzzle that has a lot to do with why I really enjoy collecting mechanical puzzles: Matchbox Play Six is a variant of Oskar’s Matchboxes – the topic of my 6th blog post (this by contrast will be my 377th post...) and one of the puzzles I blame for my thoroughly irrational love of beautifully handcrafted puzzles. 

While Oskar’s design has 5 interlocking matchboxes and can be a fairly tricky puzzle, Olexandre Kapkan’s version has six matchboxes that separate naturally into three mirrored pairs. Eric’s created them in a bunch of different exotic woods and calling it a beautiful puzzle does not do it justice. It is gorgeous!

It is great fun to experiment with and even muggins has managed to find a few solutions on this variant – from pretty compact to a big loop – a very cute variant on a classic Oskar puzzle… and it looks brilliant next to the original version!

Last puzzle for today is Uri Three Bars designed by Dario Uri. Eric’s made these with wenge legs and maple caps – a nice contrast. The object is to intertwine the three pieces so that they meet with the three caps all together…which would be simple if there weren’t bumps and grooves on the legs along the way. 

Those bumps and grooves mean that sliding any pair together so that the caps meet is reasonably easy with a little manoeuvring – but introducing the third piece requires some backtracking … if you’ve chosen the right two to start with… if you haven’t, no amount of manoeuvring will help you. 

Eric shipped these puzzles disassembled, probably just to avoid damage, not to make it harder for puzzlers.  No, I’m sure he didn’t… (nope, I’m not convinced either!). 

After a little fiddling around I thought about putting the pieces into BurrTools for some, ahem, assistance… only to realise that without know where the bumps and grooves would be on the solved puzzle, I was going to have to use a lot of variable voxels and it might actually end up taking longer than solving it by hand… so I went down the manual route… and delighted myself by solving it without having to spend absolute hours on it. 
I probably got a little lucky, because finding which two pieces to start with and then when to introduce the third piece (that’s a long way from obvious!) didn’t take too long… and finding the path through to getting all the caps together was a great reward.

Having solved it, I put the completed puzzle into BurrTools and lo and behold, there is a unique 11-move solution… and knowing from Eric’s website that it’s a level 10 puzzle, you can deduce that introducing the third piece happens pretty early on in the process!

Really unusual-looking puzzle that’s definitely accessible to non-burristas like meself. :-)

Sunday, 10 May 2015

Balls from Fuller

[...because "Truncated Rhombic Dodecahedra puzzles from Eric Fuller" didn't have quite the same ring to it...]

Eric Fuller’s been playing with some of Stewart Coffin’s rhombic dodecahedron designs recently. (Technically they use truncated RDs, but what’s a little truncation among friends?)

A couple of months ago he produced Pyracube and then last month he made a run of Five Piece Clusters along with George Bell’s Cluster with Child. The one thing they all share is that they’re based on pieces made up of truncated RD’s, which means that they go together in strange ways and tend to give rise to odd angles every now and then – which confuses the heck out of me - I have a hard enough time keeping up with puzzles where everything is perfectly orthogonal all of the time… these things introduce some wonderfully trippy diagonals as well…

Pyracube is a box-packing puzzle at its heart, but has a few other challenges up its sleeve. It’s one of Stewart’s very early designs (#19 in fact) and Stewart found it interesting as the pieces would pack, rather snugly into the accompanying cubic box either with or without the single cubie piece – using different configurations. The pieces will allow you to construct a 5-4-5 piece cube or a 4-5-4 piece cube – with the same external dimensions… that’s rather cunning.
In addition Stewart set a number of further construction challenges, starting with a square 3*3*3 pyramid and going onto a number of shapes whose name I will not even try and guess…

As you’d expect from Eric, the fit inside the box is good enough to give a little bit of a rattle so you know you’ve found the right assembly, but not nearly enough to let you consider anything too adventurous.

…Pyracube gives a nice introduction to the geometry used in these puzzles – but the next two ramp up the complexity a bit. While they may look identical in their assembled form (colouring aside) – they are very different little beasties.

So, next up is George Bell’s Cluster with Child. Assembled it takes the form of an octahedron made up of 19 truncated RD’s. Eric’s given the tips a contrasting colour and while it might not help much on this puzzle, that little feature certainly helps on the next puzzle.

Even though it only consists of 4 pieces, one of which is a key piece – that key piece is rather well conceived so it becomes pretty difficult to stumble across by accident… in fact I spent quite a while trying to find it and I’ve played with a Shapeways version several times before so I knew what to look for… at one point I even began wondering if Eric might have been having a bit of a laugh and sent me a solid, single-piece version. Eventually I managed to find the right spot and grinned broadly as it popped out leaving me with three collapsing identical pieces in my hand.

For me that’s the real beauty of this puzzle – it uses a small number of pieces – three of which are identical! Yet it forms a brilliant challenge … and in my books, dis-assembly is harder than assembly.

Great design from George, beautifully realised by Eric.

…and finally Coffin’s Five Piece Cluster (#31A) – again the target is an octahedron, but this time the pieces are rather different! As the name implies, there are five pieces, anything but identical! There’s a key piece consisting of a single cubie this time – and it’s not that easy to find, with Eric’s tolerances ensuring that you need to not only find it but also tug it in precisely the right direction before you’ll have any clue that you’re doing the right thing.

Release the key piece and you find that the remaining pieces come apart in order … this is a serially interlocking puzzle with some rather funky pieces – so you not only have to establish how they go together, but you have to work out the order that will allow you to assemble them. Definitely the hardest of the three puzzles for me… but very satisfying when you find the right assembly.