I've just thrown together a 3D print version of it (just so I can see if it'll fit) but it's surprisingly strong!.
I'm starting to wonder if I could just 3D print my own and save myself a packet. I might have a play around with some designs.. I'm thinking that instead of the mechanism that Rowan use (the notches), I could just make them gear wheels.. hmm... I wonder if that would work.