Hip Flask

Hip-Flask by Felix Ure. Dice not included.

Dear puzzle maniacs,

Here I am still in lock-down! Except that I am one of the few that are allowed out. Actually, I am forced out and I have to admit that working in a hospital is not much fun anymore. Everything we do has to be done with so much attention to detail that the stuff we took for granted now requires proper concentration and it does become rather hard work. We are doing a lot of good but very very slowly. The good news is that we are finding that a lower number of patients than expected are requiring intubation and ventilation because using CPAP or BIPAP seems to be working better. The bad news is that this still requires a massive amount of manpower to facilitate and procedures like this are counted very high for the risk of aerosol generation which means that a lot of time has to be spent wearing PPE and uncomfortable as a result. The time spent at the hospital means that I seem to have less time for puzzling just now and whilst at work have no access to my toys to solve something to review.

I am so grateful to my good friend Mike Desilets (the official PuzzleMad foreign correspondent) who has stepped into the breach to bring you something this weekend - he always is there just when I need him with something absolutely fascinating for you. Over to you Mike...



Aloha Kākou Puzzlers,

Strange days indeed. Who would have expected the present situation a mere few months back when we were glibly reading Kevin’s annual Top Ten? At times like these, a certain degree of escapism is in order. In the interest of that, and of giving Kevin a much-deserved break (you know where he works right?), I give you something to fill a small portion of your otherwise nondescript Sunday afternoon. You can take your mask off for this (Ed - yay!)

The PuzzleMad Foreign Office, Hawaii Branch, has been on a run of older puzzles recently. To remind everyone of how achingly current and hip the remote branch office really is, let’s look at a VERY new puzzle. This is Hip-Flask, the latest puzzle by up-and-coming designer Felix Ure. In fact, with this new puzzle, I think Felix has arrived. I just received my copy last week, hot off the CNC machine, which was a tremendous surprise given recent events.

As you know, some puzzles come in the door and march dutifully to the back of the queue; others jump to the front and demand your attention. Hip-Flask was the latter for me, and that’s lucky for you. If not, you would have had to endure my dissertation on a little-known peg sequencing puzzle from the Eisenhower era (it’s coming, and you’re gonna love it! Ed - I can't wait).

Hip-Flask and accoutrements.

My first impressions of Hip-Flask: this is a very high-quality puzzle; this is a very beautiful puzzle; this is a very heavy puzzle. Those are all good qualities. They describe some of the best puzzles in my modest collection. Hip-Flask is nearly 100% brass, with only one very small internal piece excepted. It is, needless to say, fashioned in the shape of a hip flask, minus curvature. This shape was not necessary and I’m sure it could have gone other ways, but I think it was an inspired choice. Proportionality is optimum and finish is beautiful, although I suppose technically it is “unfinished.” The exterior consists of the raw surface produced by the milling process. I have always considered this to be the best finish, mitigating factors aside. If you love precision machine work, you will probably also enjoy seeing evidence of it. I have a heavy Arts and Crafts bias and raw milling patterns really scratch that itch. Needless to say, it was a very successful unboxing (Ed - you mean it successfully came out of the box?). Hip-Flask is a beautiful object, no doubt about it. I also appreciate the high-quality packaging and the nice velvet bag with brass-capped drawstrings. Very classy Felix!

I am going to remain characteristically cryptic in this post because I don’t want to spoil anyone’s experience. It’s also a PuzzleMad policy (Ed - sort of!). In fact, it’s pretty much our only policy. But that makes this a tough one to review and means that our description will be restricted to the exterior. Any description I can think of regarding internals would definitely tell you something about the mechanism, so we just won’t go there. The externals are quite fascinating though. The two principal parts of the puzzle are the flask body and the “cap”. The objective of the puzzle is to completely remove the cap from the flask body. 

The rules. Not too fussy.

You immediately find that the cap spins freely, and has latitude to rise slightly from the body, at which point the spinning becomes more restricted. Something is holding this cap in place, but what? Immediately on either side of the cap are two brass rods which slide freely within precisely drilled holes. These rods feel like they should come out, but are blocked by the cap, which cannot rise high enough for them to escape. Clearly, they need to come out at some point. Turning to the base, we find a hole with a diameter matching that of the rods. Something to keep an eye on, no spoiler. Finally, there is another hole in one of the sides, but this one is occupied with a hex-head screw. This may be the designer’s entry point for inserting mechanism components, or it could be part of the discovery sequence. Or maybe both. I’m not at liberty to say (Ed - me neither seeing as I don't own a copy of this puzzle). It is, however, a very important feature if you are going to approach this puzzle deductively, which you very much should do.

That’s all you learn from inspecting the puzzle. Its massive heft (750g) suggests that there is no large internal space. This flask will not hold much alcohol, at least not the quantities that Kevin and I require (Ed - at this current time, I am getting through the pandemic with gin!).

Cap and rods rise tantalizingly.
Beyond this, you will have to work.

Usually, at this point in a post, I attempt to regale the readership with information picked up from a hurried Wikipedia search. I was sure there would be abundant cool and interesting historical factoids about hip flasks, of all things. Negatory my friends. They are exactly what you think they are, clear in purpose and intent, consistently since the medieval dawn of the very flask itself. I did come across what I think is the best and funniest explanation for the existence of hip-flasks: they facilitate drinking in inappropriate places. That sums it up nicely! 

Titan - they say it's tough

Since I cannot tell you any more about the physical properties of the puzzle, nor entertain you with historical trivia, let’s shift to intangibles. First off, full disclosure, I do not own Felix’s previous puzzle, Titan (by the time you read this I may; Ed - I don't own it either!). While I was definitely intrigued, my impression was that there might be too much randomness for my taste. I didn’t hear many people talking online about the actual solving processes; it was mostly about the raw, often substantial, solve time. There were indications that it might be a hindsight puzzle—the intellectual enjoyment coming after the “solve” when you get to find out what exactly you did and how the mechanism works. To this day I do not know if that is a fair assessment, and perhaps it isn’t, but first impressions count for a lot once you pass the $100 mark. So I gave Titan a soft pass. When Hip-Flask came along, it was billed as “a multi-stage sequential discovery” puzzle. Between that and the solid brass construction, Felix finally had my complete and undivided attention. Hip-Flask leap-frogs (say that ten times fast) Titan in price, but that is hardly worth a mention for this class of puzzle. These are the puzzles you set aside for throughout the year. 

Your next question, Kevin, will be: does it meet expectations? (Ed - it certainly is!) One can easily slap a “sequential discovery” label on a puzzle, but that does not necessarily make it so. It could very well be that Hip-Flask is sequential, but with little discovery. The process of getting from sequence to sequence could come down to random trial and error stuff. That was my post-PayPal fear.

I am here to tell you that Hip-Flask does NOT disappoint as a sequential discovery puzzle. And more importantly, it is definitely susceptible to deductive reasoning and thus “solvable” in the strictest PuzzleMad sense. There is some fiddling required to make it reveal its first secret, but that is a straight-up exploration and standard procedure for the beginning of any sequential discovery puzzle. These types of puzzles, whether locks, boxes, or flasks, generally need to hold themselves together and present an implacable front initially. The first discovery is most often stumbled upon. Thereafter, a “good” puzzle can be attacked with creative THINKing©. This is the experience I had with Hip-Flask. I admit to a certain consternation at the beginning and I struggled to understand exactly what was happening. Thoughts of gravity pins and little ball bearings were running around my head. Felix said no “significant force” in the instructions, so perhaps there is some subtle, tasteful, magnetism involved?  I didn't quite know what I was dealing with.

Hip-flask remains dignified, even when exposed.

Finally, something released or aligned, and the cap rose significantly. It was a thrilling moment, even though mostly a chance occurrence. Of course, the cap immediately went back in and locked. I then spent a good amount of time figuring out how to release it consistently. Getting that accomplished was a big moment and gave me needed momentum. I didn’t fear inadvertent flask closure anymore. This is the first phase. I recommend mastering it before you move on. Mastering this phase also sets one up for the next, harder phase (Ed - harder? OMG - I think it is beyond me already). You should be starting to understand the puzzle mechanics by this point. Also, you will have joyfully released one of the rods as well. It’s a nice little reward and a good design choice. It shows that the designer was thinking experientially, not just mechanically. 

The second phase is the heart of the puzzle, and it is where most people will have a devil of a time.

I realized at some point that I should start using my brain more (Ed - that's always a problem for me!), and thank goodness because there is virtually no other way to solve Hip-Flask. I can safely say that random action is very ineffectual on this puzzle. Shaking it or spinning the cap around aimlessly is not going to help you, and for the love of Mrs S, please don’t bang it or hit it (Ed - or she will hit you - or worse, me)! All the information you need is provided if you are open to it.

I eventually was able to deduce the exact nature of the mechanism and the exactly required movements. I used a piece of tape to keep track of my cap movements, an old and very widely accepted aid. A piece of tape is not an external tool (Kevin, please double-check the PuzzleMad policy paper we wrote on this - Ed - tape is fine because it is just a means of record-keeping). When you solve the second phase, you are very close to home. It allows you to extract the second rod and the cap is now WAY up, although still locked somehow. The two rods are obviously tools and you will need to use them somehow to solve the third phase: full release. It’s very clever how this works. Simple but perfectly effective. I believe it is a Ure original. 

Alternative reassembly via hex screw.

Reassembling Hip-Flask by reversing the solve is allegedly not difficult, but I did have trouble with it. Felix assures me it is possible and is actually how you are supposed to do it. I believe him. However, you can also reassemble by removing the hex screw on the side and gaining access that way. This works fine, you just need a 3mm Allen wrench and normal care. So no, despite my coyness previously, you will not sequentially discover a hex key. I plan to go on-line and find a nice small 3mm brass wrench to keep permanently with the puzzle (Ed - that's a nice idea).

I would be remiss if I did not mention that for a certain highly dedicated and specialized sub-segment of the community, this mechanism may seem derivative. If you think that may apply to you, contact Kevin for a hint before you purchase (Ed - I will be totally unable to help as I don't own the puzzle!). On the other hand, folks in that sub-segment may uniquely NEED to get this puzzle, though they will likely make short work of it (compared to their usual solve times at least). For everyone else in the world, this will be a challenging puzzle and a thrilling solve.

We always try to give you something a little extra at PuzzleMad, which is why you put up with our high fees, after all (Ed - fees? Are you charging behind my back? Can I have a share of them? Pretty please?). This week Kevin and I are thrilled to present you with another PuzzleMad Q&A Session: Ure-Edition! Felix was kind enough to sit down with me (electronically) and answer my trademark stream-of-consciousness questions. It’s truly very special to get a glimpse into the mind of a current designer. Thanks for giving us a piece of your mind Felix!    

Here we go...

MD:  Ok, let’s get the formalities out of the way Felix. In any PuzzleMad interview, I am contractually required to ask: What are some of your personal favourite puzzles? And is there a puzzle you love that others might find unexpected? 

FU:  I don’t think I have a favourite puzzle. I’m a massive manufacturing and engineering nerd, so if anything has been made nicely in a way that I find elegant or unusual, that does it for me. The Popplock T8 is a perfect example (not that I can afford one – I just saw a video) – it’s a very simple mechanism, but when turned into a puzzle it’s genius. I like most Hanayamas, the Cast Nut-case would have been my favourite if it was made more accurately and didn’t get stuck all the time. Basically, if I can fiddle with it and it’s heavy, I love it. I’m really not a fan of disentanglement puzzles and burr puzzles though – my mind just doesn’t work that way. That being said, I got into puzzles 2 years ago so I’m sure there’s plenty of great ones I’ve never tried.

MD:  What are the major influences (spiritual/intellectual/mechanical) on your design work and your basic conceptualization of a potential puzzle?

FU:  It’s really just anything that moves – a ratchet, an engine, a corkscrew. I’m obsessed with knowing how something is made, so by being able to completely visualize the mechanism of something, I have the perfect building blocks for a puzzle. It’s then usually in the hour or so I’m in bed before going to sleep that they somehow work themselves into something useful.

MD:  I know some designers studiously avoid tracking what other designers do, I think in an effort to maintain creative independence. Do you follow this practice, or do you take the other approach and study the work of other designers as a source of inspiration? Or something else entirely?

Hip-flask with some scale.
Good lord is that how my hand looks!

FU:  Not at all, I religiously follow everything that I can that’s out there, in the hope that I might come across a design principal or clever mechanism that I’ve not seen before. This isn’t in an attempt to get ideas for puzzles, but purely for my own curiosity and to build up my knowledge of how things move and interact. It might then help me with a design further down the line, but by then it’s far enough removed from where I saw it that I don’t think it detracts from any sort of creative independence.

MD:  Some puzzle people are heavily into solving, others mostly collect and display, another group delves into historical aspects, yet others are taken with geometrical/mathematical beauty, and some even focus on designing to the exclusion of everything else. Philosophically speaking, where does Felix Ure stand? What is it about mechanical puzzles that drives your interest, and has it changed over time?

FU:  I really only got into puzzles a couple of years ago, and while the history of them is undoubtedly fascinating, for me it’s entirely about having a nice ‘thing’. For example, on my desk, I have a brass sterling engine (which can spin from the heat of my hand), and 50mm ball of pure tungsten. Both absolutely pointless things, but both uniquely awesome. This is what I want from a puzzle – a beautiful object that you’re not sure why you want it, but you want it. 

MD:  I love that answer, and I can definitely relate (Ed - that applies to me too!). Now let’s get to an actual puzzle. Hip-Flask is your newest release, but it follows Titan, another beautifully produced brass puzzle. I’m guessing there was a lot learned in the process of designing and producing the first puzzle. What did you take away from the Titan experience and apply to Hip-Flask? 

FU:  I learnt some usual lessons about supply chain management, i.e. honesty is more important than price etc. But the main thing I learnt from a design perspective is that it’s impossible to make something that appeals to everyone. I’ve produced two puzzles which are very different; some people like one, some like the other, some hate both and some love both. And for future puzzles I think as long as the design is as elegant and well-engineered as it can be, that’s a success in my eyes, as I know at least some people will like it.

MD:  As you know, I really enjoyed Hip-Flask as a puzzle. But I think it is an aesthetic triumph as well. The flask shape suits this puzzle very well. Removing the “cap” makes perfect sense as an objective and, more broadly, the puzzle seems to strike a perfect balance between the abstract and the familiar. But given the mechanism, you could have gone any number of different ways with the overall form, even maintaining the sphere from Titan. What inspired you to use the flask shape? Where did that come from and when did you know it was “right” for the puzzle?

FU:  I’m glad you liked it, Mike! I fully realized the mechanism before figuring out what shape it should fit into. Then when working on the shape, I approached it from a machining and value perspective i.e. what is the minimum amount of material I can machine off of a stock-sized brass bar to achieve an enclosure which will contain this particular mechanism. The hip-flask shape came almost by definition as a result of the shape of the mechanism. It could have been a perfume bottle, a hand-grenade, or just an abstract form, but I liked the simplicity and, like you say, the familiarity of the hip-flask shape.

MD:  As a follow-up, what beverage would you put in your Hip-flask?

FU:  I’m usually a beer guy, but as it’s not really a hip-flask drink I’d probably go for a nice Gin (Ed - mmmmmmm gin!).

MD:  You just made Kevin very happy. Hip-Flask has three main stages, by my count. Was this arrangement the original intent, or did the multi-phase design evolve over time? Did you consider adding more complexity, or reducing it, at any point?

FU:  The original intent was to make a puzzle with a sequential element, and the idea of the mechanism getting to a certain point to release a tool was always intended to be part of it. The concept of the sequence being split into two sections really came about slightly by accident – I drew out an idea that had a ‘stop’ point partway through, and I realized that gave me the chance to release two tools, which worked out quite nicely I think. Regarding adding more complexity - it’s always hard to stop designing a puzzle; I thought about using the removed lid as a tool to unlock a further section, but then the costs start to spiral out of control, and the elegance and appearance of the puzzle is compromised to some extent. I’m happy with the difficulty level and complexity that it ended up at.

The camera loves Hip-flask.

MD:  Among high-end metal puzzles, brass, stainless, and aluminium are the holy triumvirate. I think I understand why you chose brass (cost, workability, beauty), but did you flirt with stainless or any other alloy? 

FU:  I love using brass because it machines beautifully. Aluminium (or aluminum! Ed - nooooooo!) is usually marginally cheaper but its density is nearly a third of that of brass or steel, and I love a dense puzzle. I’ve got nothing against stainless steel, but as it’s quite a bit harder than brass, the machining costs are a lot more, and I don’t think people would pay maybe twice the price for what’s basically a different colour. The amount of material machined away really defines what materials it’s cost-effective to make something from.

MD:  Follow-up, can PuzzleMad members special order Hip-Flask in tungsten?

FU:  I could look into it if a few people were interested! Ed - I might be interested!

MD:  For the technical folks, is Hip-Flask C36000 brass? Because I am always close to saltwater, I must also ask, did you consider naval brass as an option?

FU:  It’s CZ121, which is the British standard free-machining brass, I think it’s pretty much the same as C36000, which I believe is the North American equivalent. I’ve never tried naval brass as I’m not sure how it machines, so just make sure not to leave your Hip-Flask outside for long periods of time, unless you want it to go green!

MD:  I’m glad you left the puzzle “unfinished” straight from the mill. I love the patterns and texture and I suspect that it will form a very nice patina. It was probably as much an economical decision as anything, but still, what was your thinking on finish? 

FU:  I want the puzzles I make to last for decades; and from experience, if I polished them to a mirror shine they would have gone brown again within a couple of years on a shelf, or within a few days of handling. I thought it better to supply them all in the machined finish, and in a few years, they’ll all look the same anyway. Also, like you, I love the machined finish, and I think it’s a testament to the quality of the machining and the puzzle itself that I don’t need to polish out any imperfections.

MD:  I’m very intrigued by the final release mechanism. I’ve never seen it done that way before and, simple as it is, would never have occurred to me. How did you come up with that? Was it a late addition to the design, or was it always in the plan?

FU:  It was always an idea I had floating around – I can’t really remember where it came from, but it was fairly early on in the design process that I realized it would be a good, simple way to achieve what was needed, and it worked well I think.

MD:  Final Question! Now that Hip-Flask is out in the wild, will you take a breather and collect yourself, or just push on to your next project? Can you give any hints on what direction you will take next? 

FU:  Oh definitely not, I’ve got another 7 puzzles which I’m working on. Most of them are waiting for a final stroke of inspiration (some have been waiting for a year, so don’t hold your breath!) I hope to get another one finished and released this year though. I’m also working on a couple of non-puzzle things – a brass spinning top, and a high-quality ballpoint pen, but time will tell whether these amount to anything.

Thanks so much for doing this Felix. These behind-the-scenes interviews add immeasurably to my enjoyment of the hobby, and I know I am not alone. I will definitely begin stashing funds for your next release. One final word: Tungsten!  (Ed - droooool!)

That wraps up this edition. Go get yourself a hip-flask for a little drink, and then go buy Felix’s puzzle, Hip-Flask. Available at all the usual places. It’s great and I think you will enjoy it. Alright Kevin, please drag yourself away from the Benny Hill reruns for just a single moment and give us our epilogue.

Hip-flask bids you a good day.

Benny Hill reruns? Where? They are great stuff if you can find them anywhere! Totally non-PC but hysterical. Remember that they came from the 70s - a simpler time when we only had 3 TV channels in the UK.

Thank you so much, Mike and Felix! Once my finances have settled a bit and I have hopefully survived the pandemic, then I hope to get a copy of Hip-Flask myself...especially if it is available in Tungsten!

I have a week off from tomorrow - this was planned last year and I now have nowhere to go apart from to move between kitchen and conservatory and then on to the living room! Maybe I will even make it into the garden? Mrs S has decided that I need to risk my life even more, continuing with DIY and she wants me to do some exercise to prevent me from getting fat. It was "for better or worse" not "fatter or thinner" when we uttered those fateful vows! Who knows, maybe she will even let me do some puzzling?

Stay safe everyone and stay at home if you don't have to go out!

It’s Amazing How Important it is Where Your Balls Are Located

Scissors I

Scissors II

I'm making the most of one of the last weekends off that I expect to have for a while. I start a full shift system from tomorrow, beginning with a night shift. I hate night shifts...I am much too old for that as it wipes me out for days afterwards but the service needs it. Our core group of 30 covering 3 rotas has been whittled down to just 9 of us as people are redeployed to ICU or off sick. I will be providing emergency and trauma services alongside my remaining colleagues - a stressful time but the camaraderie is fantastic. The theatres are all zoned, all the PPE and protocols are available and phase 3 of our plan starts. For those of you who think it sounds like fun, let me describe the scenario...airway manoeuvres are the riskiest procedures of all for COVID-19 spread so we have to wear a waterproof gown, a polythene bib around the exposed neck above the gown, 3 pairs of gloves, including one long pair, an FFP3 mask which is fit tested to provide a good seal, a visor and a hat plus plastic washable shoes. This is worn under surgical lights for hours on end. After about 15-20 minutes the pressure of these masks hurts, after 2 hours it feels like your face is going to peel off and it takes quite a bit of effort to breathe through them so you feel like you are suffocating. Then, and this is the really bad bit...remember that you MUST NOT touch your face. AT ALL! I really don't want to be doing this for too long so take my advice:

STAY AT HOME!

This week, I have been continuing to work on equipment supplies and rotas and have had a little time to play with a toy or two. I found a couple of puzzles in my bag that had been there for absolutely ages (months) - The Scissors disentanglement puzzle duo made by my friend Aaron Wang and designed by Shuai Chi. The last batch of puzzles that I had received last year from Aaron had mostly had huge lengths of string in them and had completely beaten me but this duo were wire only and I was determined that I was going to solve them. They both look very similar and indeed, the difference is quite subtle - the position of one of the balls changes. The aim is to remove the shuttle from the bottom:

Both are described by Aaron as level 10

Now my friend Steve is a Urological surgeon and he can tell you in great detail how much of a difference it can make if your balls are in the wrong place! It is so important that surgery may be required.

I started work on these last year after I got them and initially was full of confidence...no string so they should be easy. Oh, you stupid boy! After about a week of effort, I did solve version one and took my photo:

Scissors I solved

However, I was unable to put it back to the start position. Something had moved and I had lost my pathway. Many people find that the key to solving disentanglement puzzles is to think of how to re-entangle them. This NEVER works for me. I could not for the life of me put it back together. Luckily Aaron has been sending out most of his puzzles for the last few years with quick-release mechanisms to aid with problems like this. I used the keyring on the lower ball and reset. Another few days and I was able to solve it at will. Phew - I understood a puzzle and therefore it was solved. Time for version II.

Oh my goodness! Version II was much MUCH tougher. In fact, I could not solve it. I played with it on and off for several months and eventually, it just got left in my bag to be picked up sometime in the future. That "eventually" came around just now. This week, whilst spending so much time in my office thinking of rotas and equipment supplies (getting hold of 70 extra ventilators is not an easy thing to do), I picked these back up again. Time to start with version I again and off I went. Of course, I had no recollection of the solution and it took me another 2 days to find it. At least this time I was able to reassemble it. Then on to version II. Nope! Couldn't do it! As the title of the post says:

"It’s Amazing How Important it is Where Your Balls Are Located!"

Moving that upper ball on to the upper ring adds a huge extra level of difficulty to this puzzle. After 4 days, I disentangled it:

OMG! Sooooo difficult

Yet again, I could not put it back together again and I had to use the quick reset mechanism and start again. I have taken it apart 3 times now and never managed to reset it without cheating. Each time I have solved it, I cannot understand how I have done it. This puzzle is one that I have to admit that I have never properly solved - my criteria for a true solution has been stated a few times - a puzzle has to be do-able several times at will before it can be considered solved. Whilst I can solve Scissors I at will, version II seems to be a matter of random movements which eventually work and only works in one direction.

Having a ball at too high a level can really create unforeseen difficulties for a puzzler (as well as a parent). What this has also taught me is that a disentanglement puzzle with no string can still be incredibly challenging. If you get a chance to buy any of these from Aaron in the future then you really won't be disappointed. I will keep playing with this one in the hope that I will one day understand it.

Having established that the position of your balls is crucial, I must also tell you that the TwoBrassMonkeys have been at it again and you need to push your rod into the hole carefully to "stuff the monkey". I know! I'm sorry but I couldn't resist it!

I received a package last week which "she who must be feared" put into quarantine in the porch for a few days and when it finally was let out contained a rather heavy banana:

Monkeys love bananas

Inside the banana is Steve and Ali's latest challenge for the puzzling world - Feed the monkey:

The monkey has so far been unable to swallow it all

Inside are a lot of rods/bananas

This is absolutely stunningly made (as we have come to expect from Steve and Ali). The monkeys are available in both male and female varieties (I think the presence of eyelashes is the only way to tell). At present they are fulfilling the preorders from Facebook and then later this will be available on their store. I have been merrily stuffing rods in the Monkey and have realised that his GI tract has something confusing about it as the final rod will never fit all the way in. Intriguing! Keep an eye out for this coming up for sale - you won't be disappointed. Now available here.

Mrs S Piles on the Pressure

It's a box! But I don't collect boxes. So, therefore, it's NOT a box.

Hi guys, I hope that you are all keeping safe out there? Please please please:

STAY AT HOME!

You may be fit and healthy but the UK has had a healthy 21-year-old girl die of COVID-19 and continental Europe has had a 16-year-old die too. None of us are safe - the outcome depends on pre-existing comorbidities and even more importantly viral load. If you get a big dose then you may be in trouble. This explains why healthcare workers are one of the groups with a high mortality...we just get a very high exposure level despite having PPE. Even with PPE, it is very easy to lose concentration over a long shift and rub your eyes or forget to gel your hands. Staff in Accident and Emergency departments are bearing the brunt and then anaesthetic departments as well due to the fact that most Intensive care medicine (at least in Europe and Australasia) is provided by anaesthetists. Even if you don't think you are at risk - remember that you don't want to kill your or someone else's parents/grandparents!

I am not sure how much longer I will be able to keep blogging - my duties are changing day by day and as well as clinical duties, I am working on supplies/equipment and am needing to rewrite the on-call rotas as staff get moved around. I will be doing an awful lot more nights and weekend duties over the next week or so and may not be able to solve any puzzles or write about them for a while. I'll do my best to get something for you all as and when I can manage it.

During the week things got busy and my idle puzzling time dropped to zero. In the evenings, I seemed to be unable to concentrate. So Saturday was the first day off in a while and I was determined to solve something for today's blog post. I had received a delivery from Eric earlier in the week after Mrs S released a package from its' quarantine in the porch. It had the usual orange tape marking a Cubicdissection puzzle and I spend a little while wrestling a greedy cat for possession (he lurves tissue paper and loves string even more!) Inside was a box. But no, it's not a box - it can't be because I don't collect boxes. The cavity(ies) were filled with 9 beautiful wooden assemblies - I do collect wood!!!! Drool!

9 different kinds of wood and a display case

The usual sig plus beautiful workmanship on the box

I knew that I had to have this just because of the woods and the workmanship. Plus I have become more and more addicted to interlocking puzzles. This particular puzzle - yes, it is effectively just ONE puzzle was designed by Lee Sallows (I am ashamed to say that I have never seen that name before) and fabulously made by Eric from Black Limba, Walnut, Mahogany, Leopardwood, Wenge, Spalted Tamarind, Canarywood, Quilted Maple, Paduak, Red Grandis (Box). The Blurb (which I didn't read said:

Reticulated Cubes is a fascinating exploration of 3x3 cube puzzles with a novel twist. Each box contains nine pieces, and there are eight possible cube solutions. The goal is to organize the pieces in the box such that any three pieces in a straight line will assemble into a cube (tic-tac-toe style). The solution is quite difficult to find!

So, it's a kind of Sudoku and multiple interlocking puzzles! Fab!

First of all, have a closer look at the pieces and the box:

Even the grid is gorgeous!

Which wood is your favourite?

I initially set to just random cube assembly and realised that individually they were not that hard to make (no rotations or multiple moves to get them interlocked) but then when I tried to make 2 at the same time, it got harder quite quickly and then a third was really tough! I tried again and only could make one! None of the remaining pieces could be assembled! OMG! Time to Think© (that was painful). I got out a piece of paper and a pencil and did some adding up...several times! I ended up with a plan - my plan is hidden behind a spoiler button - don't click it if you ever plan on solving this yourself.

How I worked my initial plan!

After I had done my initial planning, I set to at the breakfast table with Mrs S reading the newspaper next to me. She was a little bemused at the number of pieces and the rapid onset of muttering that occurred next to her. After an hour the muttering had escalated to swearing and she was starting to get annoyed. She asked me what I was trying to do and then asked whether I had a quieter puzzle to play with. When I told her that I HAD to solve this for the blog the following day she gave me an ultimatum...You have GOT to do this within another 2 hours or you MUST move onto something else! Aaargh! As if the pressure of work and blogging weren't enough already - she's a mean vindictive woman with a powerful right hook so I took this all very seriously.

After another 10 minutes, I actually had a second epiphany - the initial pattern that I had thought of could be narrowed down by looking at further restrictions in the pieces that can interact together at all. This was made quite a bit tougher by the fact that I seemed to be incapable of interlocking 2 pieces that really HAD to go together. Then...Aha! I had a breakthrough and some more pieces were placed in the grid and finally, just as I came up towards my deadline, I had it solved. Phew - such pressure from both puzzle and Mrs S!

The solution is behind another spoiler button - again don't click it unless you really want to see the solution.

The Sudoku solved!

Wow! What an incredible puzzle - the design is fabulous - I loved having to think about multiple assemblies that went side by side and am delighted with Eric's workmanship and choice of gorgeous wood. My addiction is well served here - even Mrs S liked the look of it even if she did not like my swearing.

Luckily I was able to solve it before she a) murdered me or b) physically took it off me and put another puzzle in my hands! Next up, my puzzle fro this evening is how to write a rota that usually has 30 people on it providing 3 tiers of cover with only 18 people, some of whom may disappear at any moment (but I don't know who will be disappearing)!  Wish me luck.

Stay safe everyone - really pay attention to what is being advised. It is dangerous out there to you and to your families. If you obey the advice then this may be under control within a month or so (ignore the "Orange idiot's" plan for Easter) and we can hopefully not swamp the health services beyond their ability to cope.

Brass is Good For Puzzles As Well As Viruses

Hyperboloid Burr from Big Steve and Ali

I really have had no time at all to solve anything this week - as you can imagine, work is rather crazy these days. I have spent my working week and my evenings trying to ensure that as people either go off sick or self-isolate that we have a fully manned on-call service and due to my rôle with the supplies and equipment groups, I have been trying to work out what we are going to need and ensure that we have it in the right place. It's at times like these that I am grateful for having a really good team of people behind me. Everyone thinks about the doctors and nurses in a hospital but don't forget that running any hospital is an army of people in the background making sure that everything runs and is where it should be. I could not do my job without them! Unfortunately, one thing that I could not just magic up was another 70 or 80 ICU ventilators and I guess that before long we will be using anaesthetic machines for it which is really not ideal. If you or your family don't want to be on one of those ventilators then you need to do what your governments are telling you...

STAY THE HELL INDOORS!

Do not socialise, do not make unnecessary trips, keep apart from each other! Only go out if you are a key worker in health, key infrastructure or work in the food supply industry.

If you are young then you will probably (although not definitely) have a mild illness but how would you feel if you killed your parents or your grandparents. The elderly or chronically ill will not do well with this virus. People are dying out there!

In this day and age of self-isolation and trying to keep oneself and one's property scrupulously clean I heard (from Big Steve so it MUST be true) that apparently the Coronavirus does not survive on brass (or copper) for more than about 15 minutes! Therefore you should all put down your porous wooden puzzles which can harbour nasties for hours or days and lay your hands on some lovely solid metal!

Now, my last blog post which mentioned the TwoBrassMonkeys mentioned Scott's Shaft and Nuts and whilst it's more of a puzzling object than a puzzle itself, it is certainly a gorgeous piece of brass which may help irradicate the virus from your hands. Now I am certainly NOT advocating that you insert Scott's shaft and nuts in any orifices as that might end up with a visit to the emergency room and you really want to avoid that just now! Plus, of course, it is very angular and has sharp edges which would be very uncomfortable. Instead, you may prefer to play with another puzzle produced by the boys, the Hyperboloid Burr. It's not terribly difficult but it is beautifully made and has two lovely challenges to it.

I had first played with a very nice wooden version of this puzzle from Allard's collection many years ago at an MPP. This was Naoki Takashima’s Exchange puzzle at an IPP. Allard teel the story that it was presented as an interesting burr assembly with six identical pieces, each shaped with hyperboloid curves. Once the initial assembly had been thought about (we all know about 6 interlocking sticks) then Naoki added an additional identical piece to the pile of pieces so that a new 7 piece construction could be made. This was exactly how it was shown to me at the MPP and I loved the idea. You all know that the 6 piece assembly looks like this:

A 6 piece burr shape

The 6 piece assembly in brass fits together only by a perfect alignment of the pieces and then with a rather satisfying click. You then have something rather fetching to hold in your hands and "remove your viruses" (I'm kidding!)

The 7 piece assembly in wood took me a little while all those years ago but was a very satisfying puzzle to solve leaving a nice grin on your face.

I never found a copy of the wooden for my own collection and was delighted to see an early version of the boy's brass creation at an MPP last year and then got a copy myself in February. Of course, it's not a new challenge for me but it is still very satisfying to assemble - the precision is unbelievable - the tolerances are to the nearest 0.03mm - any tighter and it cannot be assembled and any looser and it falls apart. Again a lovely click as it snicks together.

Don't click on the button until after you have solved it yourself.

7 piece assembly - how clever is that?

You owe it to yourself to buy something genuinely virus free and to support the 2 crazy men making us brass toys! Now I need to find some time to solve something else in time for next weekend.

Have a lovely day and stay safe! Oh yes... even if the Hyperboloid burr has no sharp edges, I DO NOT advocate internal use of the puzzle! Not even a nostril!

Packed With Thought...Which Was a Problem For Me

Pincers

Wishing Well

First of all, in view of the goings-on around the world and with my current profession, I have to advise everyone out there who reads my drivel that they need to change their behaviour now. Not later, not sometime soon! NOW! Right NOW! The COVID-19 pandemic is going to affect almost everyone around you. If it continues to progress as it has then it is likely that 60-80% of the world's population will be infected and with a 15% rate of serious illness (hospitalisation) and 1-3% mortality (depending on the population involved) then this is a huge amount of morbidity and the bodies will build up. Italy's mortuaries are full and overflowing and not just with the elderly, infirm and frail...this virus is catching the young as well - only children are relatively unscathed. Yes, if you are fit and healthy then the odds are in your favour but if you had a 1 in 200 chance of being killed crossing the road (the odds for someone 40-49 years old) then you would avoid that road! If you caught COVID-19 and remained well then great for you but how would you feel if you gave it to your elderly parents/grandparents and killed them? The best thing you can do is practice social distancing as much as you possibly can. Yes, you may need to work, you need to buy food and that is fine (wash your hands etc) but don't go to bars and clubs and gyms and spread what you have about - be careful out there! As an anaesthetist in the UK, I am intensive care trained and I fully expect to have my duties change over the next week or 2 to be more of an intensivist than an anaesthetist - I really don't want to be looking down and intubating an elderly relative of someone who could have avoided this terrible illness by just avoiding social contact. I am not being alarmist - read the accounts from Italy - the affected areas have one of the best health care systems in the world and they are overwhelmed. Awful decisions are having to be made (the elderly are being allowed to die in favour of the young) and anything which can prevent a healthcare system from being overrun cannot be a bad thing.

If you stay at home, then puzzling is a very good way to pass the time - stay safe everybody!

After I posted last week showing off the whole set of upcoming puzzles from Jakub and Jaroslav's Pelikan puzzles store, Alexander Magyarics contacted me to tell me that he was pleased that I had received a copy of his puzzles and was looking forward to hearing my thoughts on them. I had started with the Osanori puzzles because Jakub was waiting for me to write a review before they could be put up for sale and Alexander had written something himself for the item page. At the end of last week, I had taken the pieces out of their storage/transport positions, taken my photos and had a very quick idle play to reveal the scale of the problem. I had suspected that these were going to be a significant challenge and I was not wrong. I tell Mrs S that I am never wrong and my struggle with these just goes to contribute yet more evidence how right I am. Unfortunately it usually only achieves a large bruise from a Whack! Ouch! The pieces that went with these packing puzzles were pretty simple:

3 simple pieces

3 more simple pieces

There are just 3 pieces to be fitted inside a 3x3x3 space in both the Pincers and Wishing well puzzles and this looks to be pretty simple at first glance...there is a lot of space and the end result will have plenty of gaps. BUT the difficulty of these puzzles is HUGELY increased by the constraint of the entryway into the frame. For the Pincers puzzle, there are 83 ways to fit the three pieces inside a 3x3x3 cube and to add to the confusion each of those 83 ways can be rotated into 1 of 6 orientations (i.e. 498 possible cubes - OMG!) and with the Wishing well puzzle, there are 50 possible cubes with a gap in the centre of the top face for the cubie on the bucket arm of the well. To do this by trial and error would be a massive task well beyond my meagre attention span.

I set to playing with Pincers first because the slot entry intrigued me. I quickly realised that the entry through that slot reduced the potential orientations of all the pieces to a tiny fraction of those possible. I formed a mental image in my mind how I could try to find a solution and set to making shapes outside the box. There were quite a few but every time I tried to insert the pieces, I realised that the "fingers" of those pincers that cover the top form a massive restriction in what is possible. Pieces can only be lifted up when the top part is under the central slot and also not trapped under the other 2 pieces. There was much effing and blinding and Mrs S began to get irritated with me - I put it down and watched some TV before another bruise or burn occurred. The only way to solve this is to make cube shapes outside of the box and to attempt to simulate the moves required for their removal. I worked on the Pincers for several hours over a 4 day period before having a huge lucky break. The sequence required is pretty complex with the pieces quite intertwined in the box and really needing a lovely sequence to unwind them from each other. What a relief when I found it! The solved state is hidden behind a spoiler button - it doesn't give that much away but I would suggest not looking until after you have tried and given up.

OMG! That was incredibly tough.
It is solved by thought and planning only - Phew!

After my success with Pincers and with great trepidation I moved on to Wishing well. The entry of the pieces into this puzzle looks much more open and potentially from both front and back of the puzzle. The arm of the wishing well is quite mobile due to the slots on either side for it to slide through but the single cubie that hangs down from the arm is a major pain in the A! It really limits the ability to insert the pieces into the box and then seriously gets in the way of movements once inside. The final solved position is supposed to have that cubie in the centre of the top face of the 3x3x3 cube. I did find one solution with the arm of the well pushed off to one side and was actually quite pleased with myself (consider this a secondary solution to try and find). But...that was not the correct solution and I had to continue to work on it. Several days passed and I was thinking that it might be time to resort to Burrtools. The limitation on the orientation of the pieces to allow entry into the puzzle is again your friend during the exploration of this puzzle. I realised that one particular piece had to be positioned in one of 2 ways with mirror placements on the other side. Having worked this out, there are further restrictions on the other pieces. Interestingly I found that solving from the assembled state outside of the box and establishing whether I would be able to remove the pieces was not a helpful approach with this puzzle. That was a big surprise to me and I had to approach this one as an assembly puzzle with huge restrictions. It was great fun and took me 3 evenings of toil but less swearing thankfully. Last night, after work, I just managed to solve it in the nick of time for a blog post today - cutting things very fine here at PuzzleMad HQ!

Oh yes! That was great fun and a real challenge!

Again, the photo doesn't really give away that much but only press it when you are really in need. I entered this puzzle into Burrtools (I consider that part of the fun of all my interlocking puzzles) and it revealed that the disassembly solution was a nice level 7.6.8 which is quite something for such simple pieces.

Both of these puzzles have been absolutely beautifully brought to life by Jakub and Jaroslav - the workmanship is stunning (especially in Wishing Well which includes lovely dowel work to reinforce the top elements. These will be going on sale very soon on the Pelikan puzzles website and come highly recommended by me!

These will keep you nicely occupied whilst you stay quietly at home keeping your distance from others around you.

Please please be careful out there. In my career, I have seen a lot of death and illness but not on the scale that I think is about to hit many places and has already hit parts of Europe and China. I consider many of you to be good friends even if we have never or barely met in person and it would be very sad to lose you - especially when it might be avoidable. I would also not want to see you cause illness or deaths in your own family. As much as you can, keep your distance and practice basic hygiene! Here's hoping that my own viral load is kept to a minimum by the equipment I have recently been provided with! Gulp!

Packed with Difficulty

Upcoming beauties from Jakub and Jaroslav's Pelikan Puzzles

In a very short time, Jakub will be updating the Pelikan puzzles site to allow you to buy another bunch of very interesting and fun puzzles. As usual, I was given the opportunity to get them a little early to review them prior to their going on sale. This time we have 3 new beauties from the incredible Osanori Yamamoto (yes I know I have 2 copies of one of them) and a couple from Alexander Magyarics, a relative newcomer who seems to have some very interesting designs published. Jakub sold me these with the request that I try and solve the Osanori puzzles first because those are the ones he needs a blurb for on the store...the pressure is on! These puzzles always look relatively easy but are a significant challenge which I sometimes struggle to complete in a reasonable timeline. These arrived just over a week ago and I set to under pressure straight away.

Triangle Ring 3
Here it is in Mahogany & Wenge (L) and Mahogany & Maple (R)

Osanori is incredibly prolific with 256 designs on Puzzlewillbeplayed. He has an unbelievable mind - many of his puzzles follow a particular theme and look similar but all are very different in solution and challenge level. I never get bored with these puzzles! They are also absolutely brilliant to give to non-puzzlers due to the fact that they look so deceptively simple but show both newbie and experienced puzzler that a simple-looking shape and idea can indeed be VERY difficult.

I started with the Triangle Ring 3 because it looked like it might be the easiest of them with so much space to play with:

There are 2 gigantic holes to manipulate the pieces through

Jakub has now automatically been assembling the pieces in the frames in a very nice tight arrangement and I got a rather progressive surprise that it took significant work to remove all of them. I had not realised until that moment that there were so many pieces and so little free space inside - maybe this was not going to be quite so easy? When I had all the pieces out, it is my usual first task to assemble the cube shape (or cuboid in some of the earlier puzzles) outside the frame and see how many options there might be. I was only able to assemble 2 different cubes (and have subsequently confirmed with Burrtools that this is all there is) so then set to trying to put one of them inside the frame.

If you count the cubies, you will see that there are 26 and hence only one spare cubie to allow movement of the pieces in the frame - is this going to be really tough? There appears to be a really obvious logical way to go about this - start with an assembly outside the frame and perform a sequence that will disassemble it using the restrictions the frame provides. This is rather tricky with an exceptionally affectionate cat on my lap who kept rubbing his chops on the pieces and ruining my orientation. Once he had settled down to sleep I realised that the solution to this is a beautiful and extremely logical progression. It is going to require a little bit of thought and not my usual random movements. I managed the assembly in about an hour and felt very pleased with my puzzling prowess afterwards (maybe I should have learned from my previous experiences?) The level is 7.2.1.2.2 for the disassembly so not terribly difficult but requiring lots of thought. This was my favourite of the bunch.

A brilliant and logical solution

Flushed with success I moved on to the Triple 3 puzzle which looked alarmingly like some of the previous Osanori puzzles that I had played with. This one had been made from Cherry and Jatoba.

Triple 3

Removing the pieces showed that they were pretty simple and there would be quite a bit of manipulation room inside to play with:

Triple 3 - note that very unusual central piece

As usual, try and make a cube shape - oh boy there are quite a lot of them (11 in fact!) but this is reduced by the need to have a 2x2 cube at one corner and a filled-in cubie at the diagonally opposite one - my subsequent Burrtools use reveals that there are 8 assemblies that fulfil this requirement but at the time it felt like more. It became obvious very soon that this puzzle would need a completely different approach to the first. Attempted assembly outside the frame was not the way to go (for me, at least) and I would need to work on a combined approach - look for positions of certain pieces that would fill the holes in the frame and then try and insert the other piece(s) around that. The single cubie hole in the bottom would be there for a reason and that was what showed me the solution in the end.

Solved it! Brilliant! It took me 3 days!

There were several hours of swearing under my breath over several evenings of toil and included a comment to Mrs S that I might not solve this one before Covid-19 got me! Be systematic is my advice for this one. Again, it is really quite logical but still very hard to find the correct assembly (which is level 10.2.5). My shout of success dislodged the sleeping cat off my lap and nearly ended up with a scratch where I really didn't want one! Time for the final one:

Pavillion

I had left Pavillion to last because I had thought that it might be a bit of light relief from the struggle of Triple 3 - the way it was packed for delivery seemed to show that there was loads and loads of space inside and this might make the solution relatively straightforward - Lord! How stupid am I? I never seem to learn! Removing the 3 pieces showed that there really wasn't much to them:

Only 16 cubies to fit in the 27 cubie space - easy peasy? OMG no!

There are quite a few ways that these pieces can fit together into a 3x3x3 cube and thinking of that was not terribly helpful at first (there are 247 3x3x3 cubes!). OK - try limiting the assemblies to those that would close the windows in the frame - oh dear, there are an awful lot of those too (40 in fact) Having found a few nice assemblies, I realised that the shape of one of the pieces severely restricted the way it could be inserted into the frame and the precision of the manufacture meant that rotations were not possible (at least in any useful direction). Having decreased the possible assemblies by quite a bit with one single piece, I tried adding the other large piece to fill the holes in the frame and again found some severe restrictions in what was possible. BUT my brain was beginning to hurt - I was struggling to remember what I had done before and dismissed. My big Aha! moment came when I played with just 2 pieces alone and realised something very interesting. What if I did...hmmm!

OMG! I really struggled with this one

This puzzle seemed to have several phases to the solution. First work outside the frame, then restrict the orientation and then restrict it further whilst thinking of how pieces can get placed into the frame and then finally work back inside the frame to establish the exact sequence. Some rotations are physically possible and you will need nimble fingers to stop them from happening and ruining your positioning - once inside it is quite hard to see what is going on and you need to work with your mind's eye. This one took me 5 days - it is a bit of a beast (with a disassembly level of 11.7.3) despite looking so simple! It may have been that it was just my very simple brain that impaired me - I look forward to hearing whether you also struggled.

Also coming are 2 puzzles from Alexander Magyarics - I have not yet had time to solve these but they look very interesting:

Pincers

Insert these 3 pieces into the frame through a T shaped slot

Just removing the pieces from the delivered puzzle shows that this is going to be a huge challenge. My copy is made from Cherry and Ovangkol and looks lovely. I suspect this might take me a little while!

Wishing Well

Quite a mobile restriction to entry

The Wishing well is stunning! Made from Mahogany, Maple and Wenge, the aim is to place all three pieces inside the wishing well so that the only one cubie sticks up outside the well itself. I am actually struggling to see how I could even construct this in Burrtools - this one might just end up never assembled!

More Brass Beauty

B-Lock II

After last week's fabulous luck with a lock, I decided to move to the other chunk of brass in my collection that has been awaiting an attempt. As I have said before, I am rubbish at solving puzzle locks despite having several Popplocks, all of Shane's Haleslocks and a couple of other of the Feldman family locks. I had absolutely loved the first lock in my collection, the amazing (essential purchase) Danlock which is available now from Dan's son Boaz Feldman and at the Paris IPP had been completely stupefied by the workmanship that had gone into the design and manufacture of the B-Lock version I (also available from Boaz). Thus, when the B-Lock II was released, I absolutely had to contact Boaz to ask about getting a copy for my own collection and to be able to write about. He put me on a waiting list and in November had completed a bunch and sold one to me. I duly admired it (especially the very nice laser inscription on the front and matching cloth bag), dutifully tried to open it as normal with the key (failing, of course!) and then tucked it away until I had some time to properly play.

The lock sat next to the Titan lock (discussed last week) and was looked at intermittently every month or so in the hope that something like an idea would spring out at me. The funny thing is that the same thing was tried every time and each time I got nowhere. Remembering the very nice trick in version 1 I had a REALLY close look at the lock but, of course, Boaz would never do the same trick twice.

Having been triumphant with the Titan, I set this as my target for the following week and took it to work. On Tuesday, after a very nice successful Abdominal Aortic Aneurysm repair, I had a little time in the coffee room for a break and the lock came out, much to the amusement of a few nurses, ODPs and consultant colleagues who were also there.

The puzzle is a standard Israeli Nabob padlock and I could see no helpful signs of tampering apart from places where access to the locking pins had been drilled and then refilled. Apart from this and some wiggle/play of the shackle, it looked like a normal lock. The fact that the pins have been drilled always makes me wonder whether unusual things can be done with the key and I tried a "thing" or two. Nope - that didn't work but it did provide a teeny tiny Aha! moment. That's interesting even if it didn't unlock it. What if I do this? AHA! again.

Gotcha! That's really quite clever.

The onlookers were quite surprised when I managed to open this new puzzle in about 3-4 minutes and several of them wanted to have a try. I kept it a few extra minutes to make sure that I really had done the opening by design rather than luck and could confirm the mechanism. I duly handed it over and several people took it in turns to solve it. Several colleagues managed it in about 10 minutes apart from one surgeon who decided it was beyond him. It was delightful to see the satisfaction on their faces when they got it.

This puzzle is available now for about £50 and, whilst expensive, is a beautifully made puzzle which clearly had a lot of work put into the manufacture. If you can manage it, I would definitely suggest you buy all 3 - they are a really good start to a puzzle lock collection.

The Monkey's Nuts

At the last Midlands Puzzle Party, I picked up a copy of The Monkey's Nuts. It's not really a puzzle apart from trying to work out how such a strange thing can happen - The normal way a nut and bolt works is "Righty-tighty - lefty-loosey". With this beautifully made and rather large (74mm x 22mm) and heavy (1lb/454g) object, turning the nuts "righty" leaves one coming off (loosening) and the other moving on (tightening) - WTF?

I had seen this made in plastic and given away at an IPP by Scott Eliott. I thought I understood how it worked and squinting at the object in the right light gives a hint (you might be able to see it in the photo above). I showed this to a few orthopaedic surgeons who tend to really appreciate fine engineering and completely failed to explain to them how it worked. A bit of Googling about found me a wonderful description of what is going on - you can download an interesting PDF showing the trick here. It really is a marvellous idea and well worth buying a copy for yourself.