Making a hollow cage

After seeing a very nice hinged ball containing a natural pearl, I thought I would try it. It was easy making a hemispherical ball from rolled copper wire; 1.6mm copper wire was rolled to 1.8x1.0mm. Three lengths of 30mm were sawn from this. Two were given a 45° chamfer at each end then soldered at one end.

The trident was then shaped round a 16mm dome and domed in a 19mm dome. This was repeated with a second set of three strips to give two half-cages. Each soldered triplet was soldered at the other end then again domed, but in a 20mm dome with an 18mm punch. The cages looked very attractive, but the hard part is to try to find a way to hinge them neatly. I subsequently soldered a small copper rectangle, about 4x5x1mm, to one end of one triplet. This however proved not thick enough for drilling for a hinge.