Hi,
I forgot to mention…for layout, you would use a divider…scribe a centerline…walk the scribe around the band, making off stone spacing…marking off the outside metal thickness…using a metal ruler to scribe lines between stones…then using needle files to systematically remove metal to reveal the stone shapes…use first drills and then a saw to open up stone holes…shape with burs or needle files…eventually cutting stone seat with round or setting burs…
you can use a (parallel) joint needle file, or cylinder burs to make grooves to recess the prongs into…for more contact area when soldering…you can make a U with round wire to tension fit two prongs on the band at the same time for soldering…(ie: the the U is pushed up from the bottom of the band…sandwiching the band…pinching it to stay in place while soldering…later clipping the U bottom off…
if you are using a lower and upper band for the gallery rails you can use 2-4 wire pieces to separate them the proper distance…wire it together…could solder them temporarily to hold everything together and remove them later…could use them/ leave them (wire or tubing) for decorative purposes…
you could make individual collets and solder them together…but i dont know how strong that would be…each gallery rail wire would need to be thick enough…perhaps 1.0-1.2mm minimum(?) and the soldering well done…
the lower gallery is smaller in circumference than the upper gallery…this in essence creates tapered angled sides on the collet…when soldered together at upper and lower gallery, this angle creates the curve of the ring
you can use 2 round wires, vertically, between each collet, to connect them together…again making grooves for positioning…they mimic prongs (but shorter) and blend into the design, and make connecting two opposing convex curves easier…only 2 separate tangent points of contact…
or…you could use bezel blocks to shape your collets…file to shape, etc…bezel blocks usually come in 2 different side angles…they are calibrated sized, but there are ways to modify the resulting collet shapes…
in general, am thinking math and angle planning comes into play, based again in the number of stones…stone depth, etc…the lower gallery rail size determines the angle between collets…
also, don’t forget to search these keywords in our forum…a lot of good information in the archives…as well as in youtube…
i hope i am making sense…
julie