Sunday 31 October 2021

Brass Monkey 5

The Two Brass Monkeys have literally just released their latest creation into the wild and I feel the need to write about it…

They sent me a pre-release copy a couple of weeks ago and after waiting patiently until I’d finished up at work, headed home (seems weird to actually be able to say that!) and worked through the usual evening regime of penance on the exercise bike and dinner, I was finally able to sit down and have a wee puzzle.

BM5 looks virtually just like every other BM in the series – with just the slightest little detailing around the ends enabling you to tell them apart from the others – a hole and a ring mark out BM5… the rest looks pretty much just like every other one: it’s a standard six-piece cylindrical burr.

…but if they were all alike, we’d have stopped buying them after about BM3… just to be sure, right?!

So far, every one of them has been pretty darn unique, so it’s sensible to start out with high expectations… treat it with respect, don’t let yourself get lulled into a false sense of security at having solved the first four in the series (you have, haven't you?)… approach it with some reverence… it won’t disappoint.

Anyway, back to the story of my solve… I tried all the usual things one tries on a burr – heck, I even tried some of the more unusual things one might try – I’ve learnt lessons from the first four BMs after all.

None of that seems to do anything useful whatsoever…

BM5 is a very worthy successor – and I suspect it will be the most surprising puzzle that you solve this year. (I’m assuming you do solve it this year… although I suspect that it might take some folks a little while before they stumble onto the best way of solving this particular little conundrum.)

I will tell you that when I did solve it I felt the need to hop straight onto a video call with the monkeys to share my amazement /amusement / gob-smack-ed-ness – this little puzzle has given me the biggest laugh out loud moment that I can remember - equal parts “A-Ha” and “A-Ha-ha-ha-ha-ha-ha!”

If it doesn’t delight and surprise you, please check your pulse…


Sunday 24 October 2021

Holonomy Mazes


Henry Segerman has been designing puzzles and wonderfully interesting 3D-printed mathematical structures for a while now. He recently shared a video of a new sort of maze he’d designed which uses an interesting property of moving something around the surface of a three-dimensional ball-like object: moving around in a closed loop on the surface changes the orientation of that thing relative to the ball… which is interesting, as Laurie always used to say. That property is called holonomy and Henry’s mazes use that property to make traversing the maze depend not only on where you are, but how you got there…

The first two mazes he published on Shapeways were based on octahedral geometry projected onto a ball. The shuttle, which he calls a rook based on the shape of its foot that engages in the maze, starts in one place in a forced orientation thanks to the little projections either side of the insertion hole… the object is to return to that starting point in a different orientation so that one of the rook’s arms is trapped under the overhanging lip on one of those starting projections.

Travelling around the surface, every time you take the rook around one of the triangles on the surface, it rotates 90 degrees – which is helpful, because there are a bunch of pegs on the surface of the balls that will stop your progress depending on which way round the rook is positioned…  so your task is to find a permissible route around the ball that takes you back to the start, but gets you there in the right orientation – see, it doesn’t just matter where you end up, but it also depends on how you got there… nice! [Henry does a much better job of explaining all that than I do - watch his videos!]

Right – that’s the theory – how do they play?

The first two Holonomy Mazes Henry released were octahedral, as I’ve said - that gives us 24 possible nodes if we were to graph them and definitely provide a non-trivial little puzzle. There isn’t all that much space on the ball, so you never really feel like you’re lost – it’s always just a case of working out which routes are currently available and whether you want to go straight toward your goal of via a detour or three to change orientations.

The mazes and rooks are cleverly designed to allow only the valid moves and after an initial bit of playing any roughness on the prints is smoothed away… I quite like these little mazes because despite having such a small physical area, they provide a neat little challenge.

A few weeks later Henry presented his Dodecahedral Holonomy Mazes so I had to give those a bash as well. This time you have 120 nodes potentially available (before the pegs begin to limit that space) and a circuit of any one of the pentagons will translate the rook by 60 degrees this time… where the smaller mazes feel like they should be simple, the dodecahedral ones feels a lot more complex, at least to me they do – and watching the videos where Henry describes the process of deciding which mazes would be interesting, I’m not surprised – he’s deliberately chosen layouts that have lots of spaces where a puzzler can easily run around in circles for a while (yup, I’ve got the t-shirt!) and also have some bottlenecks in the middle so if you don’t pick the right path at the right time, you’re doomed to wander around in those almost-closed loops.

These puzzles are not only fun to play, they’re also interesting for how make use of such a relatively small space while producing interesting, non-trivial puzzles. 


Sunday 17 October 2021

Nuts N' Bolts

A couple of weeks ago I spotted an announcement from Phil Wigfield on Discord that he’d be releasing a new brass bolt puzzle in a couple of weeks’ time, so I made a mental note to keep an eye out for it on his Etsy shop

A couple of days later a package arrived from Walsall out of the blue – which surprised me at first, but the note inside really blew me away. It was a letter from Phil gifting me a copy of his latest as-yet-unavailable puzzle Nuts N’ Bolts. Thank you, Phil!

I was quite keen to play so I opened up the customary little wooden box and lifted the little contraption off its satiny pillow – it’s an interesting looking little beastie – a pair of parallel bolts courtesy of a pair of fat conjoined nuts seem to be held together by a single nut and bolt combo that pierces the whole lot of them… and trapped far out of reach is a pair of washers that you’re aiming to remove.

Seems obvious that you need to remove the crossing bolt and then you’ll be able to remove the big bolts and Robert’s your mother’s brother. Only it’s not quite a simple as that… you might find the first step works pretty much as you’d hope, only from then on things get “interesting” – and by “interesting”, I mean all progress ceases!

Definitely time to Think(c).

There is a beautifully elegant solution that leaves you with a pair of freed washers and a nice smile on the face.

At this point you’ll know exactly what he’s done to create this little piece of glorious engineering, but I defy you to find the traces of his handiwork… he’s gone to a lot of trouble to keep things unseen that should not be seen… it is beautifully made, and a lovely puzzle – and if I hadn’t just been given a copy, I’d be queuing up for a copy when they’re released...probably tomorrow. ;-) 

You're welcome!

Wednesday 6 October 2021

Popplock T13

Some things in life are very reliable – take Shane’s opinions on puzzle locks for example: if he rates one highly, then chances are good that any mere mortal is going to find that very thing absolutely astounding, so when he put a picture of a new T13 on Facebook and began singing its praises, I knew we were in for something really special…

Of course, given the opportunity to buy a shiny new puzzle from Rainer, I’m more likely to mortgage a kidney than pass up the opportunity, so when the opportunity arose, I accepted, perhaps a little more eagerly than usual given Shane’s unbridled enthusiasm.

First impressions of the T13 are, indeed, impressive – this object has presence – it demands attention – it also demands a sturdy surface to play on given that it’s a huge two kilogram lump of steel and brass.

The shackle appears to be made of three thick sheets of hardened steel riveted together – reinforcing its pedigree as a proper, if somewhat oversized, lock. The keyhole is offset at a jaunty angle begging to be played with. The back has a springy disk with Rainer’s customary logo and the lock’s name engraved on it… and the only other slightly unusual feature are two disks on the top of the lock inside the shackle… the rest looks pretty, er, lock-like.

I started by doing the obvious and immediately I knew by the gentle click and my inability to reverse my actions that Rainer was already laughing at me… I’m sure it’s only me, but I got suckered in and knew I’d done something a little silly right from the very beginning. (In my defence, I think you have to…)

I won’t bore you with all of the details, but I will tell you that the solve took me weeks. I spent a long time thinking that there was absolutely nothing else I could try, explore or experiment with, only to make the tiniest little discovery a few days later and then find myself trapped for a few more days.

The solution path on this one is well and truly long and winding, but along the way you will be rewarded with several fantastic “A-Ha!” moments when this little lump of metal does something utterly wondrous – if your jaw doesn’t hit the deck at least three times when something strange happens, then you aren’t human!

This puzzle keeps on surprising you right up until the very end… and even the final element is good enough to hold up a seasoned puzzler for the best part of a week or more (not me, a friend – I’m not that seasoned!).

Another phenomenally good puzzle lock from the master-craftsman – a worthy successor to all of his foregoing Tricklocks – another Jaw-dropping mechanical masterpiece… Oh, and Shane was absolutely right!