G’day; The method I mainly use for making rings is the ancient one
used before rulers were invented. I have the customer take a piece
of soft wire - florists iron wire is excellent - and have them make a
single wrap around the appropriate finger, then twist the ends of
the wire to form a loop exactly right for them, that they can move on
and off easily but not too easily. When THEY are completely
satisfied, I take the wire, cut it in the middle of the circle with
nippers, then straighten it out on my bench peg, leaving the twist in
place. I now lay the wire on the bench top and place the strip of
ring metal at right angles to it and mark off the beginning and end
of the length in pencil. this allows for metal thickness when joined.
Next I place the ring metal beside the marks and so mark that length
on the ring metal and make the cut. And it’s all over besides
bending, soldering shaping;…etc etc but it is accurate.
I have long used that practical method when cabinet making, etc; I
mark actual dimensions on a piece of flat stick, which then becomes a
sort of ‘record’ and hung on a nail for future instruction if I have
to make another. Numerically challenged? Who, me? How did you
guess? – Cheers for now,
John Burgess; @John_Burgess2 of Mapua, Nelson NZ