Hello Kent, and everyone.
“Flush” setting, or as it is more commonly named “Gypsy” setting has
only one watchful problem for beginners…and here is the method in
negotiating the stone into the hole.
You said that you have all of the right size of burs, great. I would
now ask you to look very carefully at the very top rim of the
prepared hole…you will notice an overlap of metal. Your problem is
that you haven’t opened up the hole wide enough to allow the stone to
"snap-in". If you try and exert too much pushing, you will find that
you can now easily break the stone.
Get a round bur about 80% of the stone size and slightly remove more
of that overlap of metal…Do this a few times till the stone almost
slides in. But do not remove all of that rim of metal. This the
"trial and error" part of Gypsy setting…
Be very careful of how much you grind away…remember that you are
only going to be removing only little bit of metal at a time…don’t
grind away everything…you still need that rim to press down to
secure that stone…
I would re-check how much you drilled with your Hart bur ( a.k.a.
156C), you might have to re-access your under-cutting again at this
time…I prefer only the 90 degree hart bur, why? It is shaped at the
same angle as a regular faceted stone… 45 degree is too shallow for
basic setting…hope that this little reply helps you…