Saturday 7 September 2019

Nova Plexus

I love a good story. And when there’s a puzzle involved as well, even better!
This design has been around for a long time – but it was made in such limited quantities that the only way to see one or play with one was to visit Luppitt or Bloomington – well not quite, but there were only twenty six copies made, and at least three of them resided in those two collections. So your odds of stumbling across one weren’t very good. Add to that the challenge of assembly, and their ability to instantly and spontaneously disassemble if any of the joints gets tweaked, and your chances of ever seeing one assembled in the wild was rather limited.
I first found one as a pile of sticks at James’ place several years ago – James gave us all the history of Geoff Wyvill’s neat little design and told us about the somewhat limited run that had been manufactured at the time, and told us just how hard it was to assemble – that challenge, a few rubber bands and a picture of the assembly were enough to enable Oli and Chris (if memory serves correctly) to assemble the sticks into a pair of Nova Plexii (‘cos that’s clearly the plural, right?!). James was happy. We were happy. The universe was at peace.
Fast forward a few years and Nick is visiting the Puzzle Museum for the first time ever and he picks up an assembled Nova Plexus – he knows the history and wants to handle it – James looks nervous and says “Be careful” just as Nick twists one of the joints ever-so-gently and there’s a tell-tale tinkle as twelve steel rods collapse in a mess – James looks mildly disappointed.
And that would have been a great story – but it gets better – this little interchange prompts Steve and Ali to borrow a set of rods and explore the possibility of getting them manufactured with the blessing of the designer… which is ambitious because there are several legends of others trying and failing – even engineers with access to some wonderfully whizzy kit haven’t been able to reproduce the precise dimensions and curvature required to get those little rods to hang onto one another just enough to assemble perfectly. At least one of our friends has tried, and failed…
Undaunted, the lads have a chat with the designer and then consult their man-in-a-shed who reckons he’ll give it a go… and things look promising on the first few prototypes and shortly afterwards they’re good enough to make the guys believe they’ll be able to actually offer them for sale…
When it was designed in 1978, Monty, a mate of Geoff’s at the University of Bradford had made 26 stainless steel copies out of a planned run of 500. After the first 26 copies were made, production stopped, and for forty years there have only been 26 copies in existence.
Thanks to the Two Brass Monkeys, that original run of 500 copies will now be completed.

OK, that’s the back story…. Tell us about the puzzle!
Nova Plexus consists of twelve quarter inch stainless steel rods, each with a precisely machined notch at each end. Those twelve rods assemble into four triangles which each interlock with one another in such a way that the whole assembly is self-supporting – with only the friction at the notched ends and between the rods holding things together.
The kit comes with a small bag of rubber bands to assist initial assembly – although interestingly, once the first three triangles are interweaved, the fourth can be introduced without needing rubber bands… and while my introduction above paints a picture of a rather tricky assembly, I’ve honestly found they go together quite predictably as long as you make sure that the corners are properly aligned along the way and the triangles are properly weaved. There’s a lovely symmetry in the assembly with each rod weaving in and out of each of the others it crosses, ensuring there’s quite a lot of tension holding it all together.
The Boys are selling the original steel Nova Plexus on their Etsy shop bundled with a brass copy – think of it as a buy-one-get-one-free deal… on a puzzle that hasn’t been available for forty years.
As an aside – if you prefer your metal shiny, the brass copy shines up beautifully if you take the trouble to rub a little metal polish over it. Well worth the (limited) trouble in my books!


  1. Very cool! The symmetry of the assembled shape is fascinating, I don't quite understand it at the moment!

    1. ...look at the (four) triangles and remember that it needs to be forcing itself outwards. :-)

  2. This is my kind of puzzle! Nothing hidden, all geometry, looks cool. Easy purchase decision!

  3. My Nova Plexi have arrived and I really like them! I didn't think I needed two copies but it is rather useful. What you can do is assemble one and then use it as a model to make a second, all before removing the rubber bands. This is a great puzzle!

    1. Excellent - glad you liked 'em... BTW Louis MAY have found a way to intertwine multiple sets...