After having assisted Wil Strijbos in the Edward Hordern Puzzle Exchange at my first IPP, I’d pretty much made up my mind that I wanted to participate in the exchange myself, so on the bus on the way to the National Cryptographic Museum I asked Wil for some advice and his first suggestion was that I chat to our friend Louis Coolen about possibly designing a puzzle…
Shortly after getting back home, I floated the idea to Louis and he was pretty keen and said that he had a couple of ideas he wanted to work on… and that he might be able to do something. On his next MPP-visit he arrived with a prototype of what would turn out to be the main locking mechanism built into a small aluminium briefcase. Fairly early on in the process we’d settled on using the aluminium briefcases as the vehicle for these puzzles knowing that we could source them reasonably cheaply from the Far East and knowing that would take a lot of pressure off the manufacturing process (i.e. we wouldn’t have to make up a hundred boxes!).
The first prototype had the guts of the mechanism mocked up in wood using a rubber band, some Geomag bits and a drinking straw! Heath Robinson it might be, but it worked and showed us that the main concept would be feasible… in short the case would open a bit and let you see some of the insides, but it would not be able to open fully, until you defeated the locking mechanism.
Noticing that there was a reasonable amount of space still available in the case, I made some suggestions for a fabulously complicated lock that would prevent the case from being opened at all – Louis duly mocked one of those up and built it into a prototype and brought it over on his next visit – but we soon abandoned it as there was so little feedback and the mechanism was too hard to fathom…
Having settled on the basic design of the locking mechanism, Louis then taught himself to use Google SketchUp and set about producing a three dimensional model of it suitable for printing by Shapeways. He’d sensibly tried a couple of variations in the print run so he was able to try various alternatives in a single batch … and over the next couple of months the designs were tweaked until the mechanism itself had just enough strength where it was needed and not much additional material – then he made it look good by adding some wording into (and onto) some of the bits and it started to look rather jolly professional.
Somewhere during that refinement process, I came up with a means of adding another little layer to the puzzle by putting something inside the case to provide an extra little challenge (some laser-cut shapes to make up a target, unspecified, shape). True to form, my first idea was so darn complicated that we abandoned it after I tried it out on Louis and even though he knew what he was trying to do, he couldn’t make it work… so we reverted to a far simpler challenge and this time Louis not only found the intended solution, he also came up with some interesting alternative constructions … and some suggestions for tweaking the pieces a bit to add a soupçon more subterfuge.
In the interim we’d sourced some clear tubing to house the wands and came up with a reasonably efficient way of turning large quantities of Neodymium magnets into magic wands – my least favourite part of the jobs I ended up doing on the project – although I still think I got the easier parts of the project!
Having an open mechanism inside the case meant that the mechanism would need to be shielded from the laser-cut bits somehow, lest they wander into the mechanism and either jam it entirely, or more worryingly for us, assist the puzzler in opening the lock! And so it came to pass that Gill got roped in to provide 150 tiny drawstring bags, with the tiniest Neodymium magnets you’ve ever seen carefully sewn into their seams. [Don’t ask…]
Once we’d finalised the laser-cut shapes for the secondary puzzle, Louis lined up Peter Knoppers of Buttonius to do all of our laser-cutting. Peter provided a small sample run and once we’d confirmed the sizing and shapes he duly produced the rest of the run – including putting each set of pieces individually into plastic bags – which made my life heaps simpler – thanks Peter!
Louis sourced a supplier for some black mini-briefcases via eBay and once they’d arrived he noticed that the spacing on some of the features of the case was ever so slightly different so he made some final adjustments to the printed bits before placing the main order with Shapeways… who by this stage have got to know Louis and have been asking how the various prototypes have worked out – awesome customer service for a company that must deal with thousands of customers!
Around this time we go through an important rite of passage for any potential exchange puzzle: review by the committee to ensure that the puzzle is “good enough” (my words, not theirs) and hasn’t been commercially available previously… I write up some stuff and attach some pics that Louis has taken, being careful not to spoil any of the puzzle-elements as I’m pretty sure that more of the committee will be in the exchange and I don’t want to give them any clues… you know, so as not to spoil their fun! The committee lets me know that the puzzle is approved in pretty short order so we’re off…
With a couple of months to go until IPP33, Louis has a pile of black mini-briefcases, a box of clear tubes and a few bags of printed bits from Shapeways and I have piles of magic wands, stacks of bags of acrylic bits and a steadily growing pile of little drawstring bags.
Louis and Mieke spend many a late night over the next few months selectively cutting the lining out of the cases and gluing in bits of locking mechanism and the clear tubes – with the last of the IPP-bound batch literally being finished on their UK holiday just before I leave for IPP.
I become reasonably adept at putting the acrylic bits in their drawstring bags (they need to be packed in carefully to get them into two layers or they’ll get in the way…), testing the glue joints, affixing stickers to the case and box and then packing them all up in their original bags and boxes… until I have a hundred of them to take along to Japan – mostly for the exchange, but also as gifts for some old friends and some new IPPers (I blame Peter & Ginda! ;-) ).
The puzzle goes down really well during the exchange and folks all say kind things about the puzzle (so we know it looks good!). Later on I spot a couple of folks trying to open them and doing exactly what we wanted them to – all of it useless! At dinner the next evening I spot some people puzzling away on them and I don’t spot anyone opening one… this is going well…
I’d agreed with Wil Strijbos up front that he was going to get a bunch of them to flog and I give him the first few of those on Sunday for the puzzle party – and while he doesn’t get rid of them all, he’s still keen for some more…
After IPP Louis takes charge of the entire manufacturing process and assembles the remaining 35 puzzles and passes them onto Wil … so if you want one, he’s the man to speak to, as I literally only have my own copy left now… (not counting a set of prototypes that lead up to the final design).
What’s it like as a puzzle? Well we’ve had some good feedback, and Wil says he likes it … we tried various incarnations on the patient folks at various MPPs, and they mostly liked it. My own description at IPP was that it was a puzzle of two halves – Louis designed one half (and it’s awesome!) and I designed one half (and it’s naff!) and once you’ve finished the puzzle, you’ll know which bit Louis designed! :-)
…if you do have a bash at one and you manage to come up with some interesting constructions for the second bit, please let me have a pic of the results – I’ve started collecting pics of almost- or indeed not-solutions - so far Peter’s is the best not-a-solution although George’s were pretty ingenious in their interpretation of the challenge!
Thanks Louis for all your hard work on this – I really appreciate it!! And to our better halves, Mieke and Gill, who got dragged in as well – thank you too… :-)
Now, about next year…