Lock it in, Eddie

Over the past week I've been developing a means to lock the rotating rods so that my needlebox functions correctly. An animated conversation I had with a mate of mine at home inspired a few ideas and now I think I have a definite track to follow. Full credit to AJ for the following work of art, from which I was able to develop a coherent series of sketches that eventually evolve into something that might actually work;

Cheers AJ

As for my own development of the concept;

As I couldn't find anything like what is shown in these sketches in the shops its up to me to make the locks. Typical...

The most reasonable and durable option apparent is to solder a ridge onto the underside of the hinge which would jam inside grooves carved into the wooden rods. Using screws would still require solder as a seal and a wooden wedge would eventually wear out. So it was off to the workshop to prototype;

I found after a lot of waiting, that the solder disagreed with the metals I was using and wouldn't attach to them. A solution, it seems, is to change my ridge wire to something other than aluminium and sand off the layer of oxidised metal on the hinge and hopefully some progress can actually be made. But hey, this is what prototyping is all about.
An alternate, but considerably more elaborate solution cooked up in the workshop is to use ball bearing in the way they feature on adjustable-height crutches. Instead of one bearing, however, there would be several staggered around the rod, which would be inside a tube with holes in it for the bearings. This solution would require a lot more delicate work and is a bit less desirable for my inexperienced workmanship.

Here is the sketch nonetheless.