Visible Burrs

('cos invisible ones are hard to photograph) 

The universe has a strange sense of timing…

A while ago I managed to snag a single item off Nick’s auction – a copy of Bill Cutler’s Visible Burr. It had been made by Brian Young as a Limited Edition back in 2005 when he produced 30 copies. 

Now it’s fair to say that I hadn’t been paying particularly close attention to the listed dimensions on the auction listing so I was a bit surprised when it arrived … it is large! And very Mr Puzzle-y – the woods instantly give Brian away, and the finishing at the end of the pieces should probably be a Mr P trademark by now… and if there was any doubt at all, he’s branded it with his logo.

Right, so said puzzle has been staring at me from atop my cabinet for a few months now as I haven’t had much time to play with puzzles recently… guilt growing by the day. 

…then a couple of weeks ago Eric Fuller announces a new set of puzzles available for sale, and one of them is none other than Cutler’s Visible Burr, and I can’t stop myself from ordering one, so soon enough I have a second copy mocking me while I’m not puzzling… this one’s disassembled as Eric was charging an assembly fee for this one (and having now played with them, I know why!). 

Seeing as how is was a long weekend I decided to give myself a day off to play with puzzles, so I ended up spending the best part of the day assembling and disassembling a pair of Visible burrs… and it was great!

Let’s start at the big end – Bill Cutler designed Visible Burr to be a disassembly challenge and deliberately made all of the notches in the sticks visible, even when it’s fully assembled – so by inspection, you should be able to deduce how to dismantle this 24-piece monster.  You effectively have a 12-piece burr trapped inside a 12-piece cage, so examination of the inner burr will show you which pieces can move where…

…and at this point you might notice something interesting – there’s a lot of sticks that can move at most points in the solution – only some of them are useful! You will find yourself wandering down a lot of blind alleyways if you don’t examine carefully and think a few moves ahead. (Or you can just play, experiment and fiddle around if you don’t mind going backwards and forwards a bit – which is my preferred approach!)

The first piece needs 7 moves to release it, with the next following along after another couple of moves. Release a few of the inner pieces and you’ll find you can start removing cage pieces too … and then carnage prevails as pieces start flying off left, right and centre. (I have a vivid imagination, stay with me!)

Keep on going and I have a large pile of large sticks. Yay. (What the hell did you do that for?!)

OK, now we pick up the smaller sticks form Eric and set about building that into the same sort of structure… now the three type of wood really help things, as does the fact that the frame pieces are all identical – which means the only real challenge is the 12 internal pieces – the rest is just about timing, timing and dexterity – did I mention you’re wrangling 24 pieces?

Now at this point, dear reader, I shall not insult either your intelligence or my imagination by suggesting that I put it back together unaided – I fired up my trusty copy of BurrTools and spent many pleasurable hours building a suitable model of the monster… so I now know that the complete model consists of 7868 voxels(!) – think about that before you chastise me for using software – that was a labour of love! 

BurrTools found a suitable solution in mere seconds, but it took a lot longer than that to actually build up a copy in the real world… oh and then there was the reassembly of the big bugger as well.

So I started the day with an assembled giant copy and a small set of sticks, halfway through my day I had a large pile of sticks and a small Visible Burr, and at the end of the day, I now have a reassembled monster on top of my cabinet looking down on my with grudging respect and a neat little copy in the cabinet on the Fuller shelf… a good day’s puzzling all round!

…a little treasure…

A little while ago I managed to pick up a couple of lovely little bits of puzzling treasure..

First on the list was a particularly gorgeous creation from the mind of Oskar and the workshop of Tom Lensch. I’ve been trying to get hold of a copy of Wanderer for a while now and on the odd occasion when I spotted one in the wild, I didn’t have enough cash left in my wallet… this time I saw it coming and made sure I was suitably liquid and managed to snag myself a copy.

The concept is simple, a shuttle is captured inside a cubic cage with a number of strategically placed notches in the walls allowing the shuttle limited movement due to a couple of pairs of protruding bumps on its sides. The shape of the shuttle itself allows some interesting movements between both opposite and adjoining sides of the cube, but only in some directions … and then only when the notches / bumps allow.

If that all sounds rather familiar, it probably is since the Hanayama Cast Cuby is a scaled down shinier version that simplifies the construction a little… although I suspect that the simplification hasn’t done anything to reduce the solution-depth.

I just love the look of the thing – way the shades of the different woods on the shuttle play out across its rounded underbelly is just brilliant. The beautifully precise work on the corners of the frame is tremendous. Definitely a little treasure to add to the collection.

Next up was a variation on another puzzle on the collection already. Three-Piece Blockhead was Bill Cutler's gorgeous IPP15 exchange puzzle. As the name suggests, it’s a variant of the famous Blockhead puzzle that only uses three pieces.

Instead of four blocks in a square frame (honest guv’) this one asks you to simply place three cherry blocks into a hexagonal walnut frame. Everything looks neat and tidy when the three blocks are in the frame to start with, but tip them out and it’s rather obvious that there was a little subterfuge just below the surface of that little puzzle as the blocks aren’t really shaped the way you might expect, so finding the right way to put them back into the frame is a non-trivial task.

A great puzzle to give to muggles who scoff at the idea that putting three blocks into a simple looking frame might be in the slightest bit challenging… a lovely little piece of puzzling history to go next to my standard four-piece Blockhead. :-)

Lastly a lovely little Eric Fuller creation that has been on my lust-list for ages… it was one of those things that jumped out at me from Eric’s gallery pages as being simply stunning – Alfons Eyckmans’ Lolly Box. Four colourful wooden Lollies are packed in a walnut box so that only their sticks protrude.

Removing the first takes a reasonable 4 moves, as does the second, but this puzzle shows its true colours when the next piece requires a further 17 moves to release it! I’d originally lusted after it mainly because of its looks – I know – I’m really shallow! But now that I’ve had a chance to play with it, there’s a lot more to enjoy about this puzzle than just its looks…

It’s been beautifully made by Eric so the pieces need to be aligned rather neatly to enable the necessary moves… and those internal protrusions are in just the right / wrong place – depending on your point of view.

A stunning little puzzle that I’m glad has now moved off the lust-list and into the little collection.

Cutler Cube

This thing’s a beast. 

It is big. 

It is heavy.

It has 66 pieces.

11 moves to get the first piece out.

…but it’s a classic!

Bill Cutler began developing this design in the early 1960’s, with the first version seeing the light of day around 1965. It was specifically designed to be a burr that was hard to take apart, as well as put together. Another two versions followed over the next four years with the third version becoming known as “Type A” – or this particular version. (Several more versions have appeared over the years… all intended to be even harder!)

Just think about that – Bill designed this in his teens, by hand – and it’s still a classic 50 years later… little wonder he went on to become one of the best known designers around!

Bill describes the Cube as being made up of two main structures – an inner cage consisting of a standard 24-piece burr (picture 8 inter-connected 6-piece burrs at the corners of an imaginary cube; and an outer shell consisting of another 41 pieces. The two structures are locked together using a key-piece … one that takes 11 moves to remove (so not a key-piece in that sense!).

When Eric Fuller announced back in January that he’d been given permission to make a run of Cutler Cubes I immediately signalled my interest – and followed the pics as the piles and piles of pieces grew in Eric’s workshop – sadly including a large pile of mis-cut pieces that got trashed because he’d used the wrong wood. In spite of the mishap along the way, Eric duly announced that he was done and was proud of the results – so I knew it would be awesome – Eric sets himself very high standards!

I wasn’t disappointed when it arrived – it looks stunning! The original Cubes were made in walnut, oak and mahogany and Eric’s traded the latter two for ash and sapele – keeping the overall colour scheme and looks true to the original. Neat! The fit is definitely up to Eric’s usual standards … this is going to be brilliant!

As soon as you start playing with it, you realise this isn’t going to be a walk in the park – you can find a few things to move … and that movement opens up yet more movement, but then you stop dead in your tracks. Bill’s designed a bunch of dead-ends and red herrings into this brute and I’ve been caught hook, line and sinker!

I try a slightly more rigorous approach but still find myself wandering into the same blind alleys. Clearly this is going to need a serious approach, so I try putting on my puzzling hat and this time notice something “interesting” that I haven’t spotted before – it’s beautifully hidden – and then all of a sudden you know you ain’t in Kansas no more – something very unexpected happens – and that really sets the tone for the rest of the solve – you know you’re on the right track now – that’s fantastic!

After that key-piece is removed, they start coming apart thick and fast until you find yourself left with that inner cage – the 24-piece burr at the centre of the Cube – even then it isn’t trivial.

Faced with a pile of 60-odd pieces I do what every sensible puzzler would do, and drop Eric an email asking for the solution – it duly arrives along with a PDF of Bill Cutler’s original notes from 1980 – including drawings of the pieces and their positions, and quite helpfully, some additional construction notes from Eric on how he chooses to assemble them – after all he had to assemble a run of 38 of these brutes so he had to come up with a fairly repeatable process.

Even with the benefit of all these pictures, notes and instructions, I still make heavy weather of it – having the partial assembly come tumbling down a few times before I managed to get enough interlocking-ness into the structure to keep things together and then finally manage to get it all back together again… serious sense of achievement ensues.

Back in the 1960’s Bill Cutler set out to design a burr that was a challenge to take apart. Fifty years on I’d say he was pretty successful at doing that on his Cube. Eric has produced a fantastic version, true to the original with tremendous tolerances, brilliant fit and a lovely finish… an excellent puzzle to have in the collection.