I am no expert, but I think that what Rick is talking about is
what I call a collet block (sometimes called a setting block) and
set of punches. One first makes a thin tube (soldered, of
course) of height the same thickness as the block, and outside
diameter the same as the narrowest diameter of the tapered hole.
One inserts the tube into the appropriate hole and carefully
taps the correct punch into the tube so it fits the hole nicely.
And voila! One has a conical setting for round stones. One can
file away parts of the top of the cone leaving claws, if one
wishes. I have to admit that I couldn’t afford one of these
sets - they COST! so I made mine from a small piece of 3/8" flat
steel, and the punches of 1/4" round steel which I put in an
electric drill and ‘turned’ with a file and grades of abrasive
paper. For the holes I made a sort of drill something like a
conical countersink tapered to the proper angle from silver
steel. This when hardened and properly tempered sufficed to cut
the tapers in previously drilled holes. Remarkably enough, the
gadget reallyworks. (all one word “as seen on TV”!) I like making
tools. And a Happy New Year to all lour readers.
/\ / / John Burgess, J.O.A.T; M.O.N. / / / //\ firstname.lastname@example.org (Jack-of-all-trades; master of none) / / \ \