Learning tension setting

I am also entirely self taught. It is true, as Gerry said, that
having an expert nearby to ask questions is very helpful but one can
also learn through books and experimentation, it just takes longer.
You might develop a better way of doing something through your
experimentation. I think I have in a few instances I don’t know the
"accepted" way to make a tension setting but I have made several and
the diamonds are still secure after a number of years. I carved my
waxes with a cnc mill but it would be no problem to do them by hand.
I made the shanks very thick to provide maximum tension. I used a
heat treatable yellow allow for the casting. After casting, I cut
the seats in either side of the tension setting. Great care has to be
taken here. If they are not perfectly cut the stone will not be
level. Put the stone in the setting by putting the ring on a mandrel
and forcing it open enough to drop the stone in, then force it back
down the mandrel to close it. I usually have to do this several times
, adjusting the seats each time until I am satisfied with the fit. I
remove the diamond one last time, and close the gap a couple of
millimeters using ring bending pliers. After this I heat treat the
ring and reinstall the stone again using the ring mandrel to open and
close the setting. The ring mandrel I use is one that I use for
polishing rings and its surface is now highly polished.

For what it’s worth, I think tension settings are a stupid idea and
I no longer make them. They must be a bitch to resize. I’ve told my
few tension set customers that they will have to have a new setting
made if sizing is required. You can get the same effect by closing
the channel with a ring under the diamond which is smaller than the
width of the diamond. To set the stone, I cut the shank at the
bottom and bend one side of the shank so that the two sides overlap.
I then carefully push the two bottom sides together opening the
channel at the top of the ring. When the opening is large enough to
slip the stone in, I tighten it by opening the bottom of the ring .
I repeat this process recutting the seats each time until I get the
right fit, then solder the shank and finish. If the wearer gets
fatter as she ages there’s no problem sizing the ring.

If she goes on a diet , you might have a problem finding a way to
tighten the stone.