Hi
How do I make an oval bezel for a 6X4mm facetted amethyst? what is
the length of the strip that i cut? tried a couple of techniques but
they seem to work on approximations…and the collette turned out a
little small. Is there a fixed formula?
And Congratulations on the new snazzy Orchid look! It’s so much fun
to go through the digest in colour.
Thanx
Pallavi
www.pallavigandhi.com
I use a thin strip of paper wrap it around the stone cut across two
ends to give the perfect size every time.
Pallavi the bezel or collette being a little small is a correct step
provided the seat for the stone is not yet cut or added on. A bezel
can then be tapped up to the exact size and adjusted to the exact
profile on an oval mandrel, on the horn of a bench anvil, or by
pinching all around with a pair of flat/round-nose pliers.
Calculating the length of strip for an oval is quickest by treating
it as a circle. If the oval is bent into a round, the diameter of the
round will be the long length of the oval + the short width of the
oval divided by two. In your example 6 + 4 / 2 = 5. Make a round
bezel of 5 diameter and then force it into an oval. The length of
strip needed for a round of 5 diameter is D, so it is x 5
Is 22/7 or 3.14 so 3.14 x 5 = 15.7… but if you use just = 3 the
bezel will be a little smaller and can be stretched up to “fitting
size”!
Alastair
they seem to work on approximations
Sometimes precision is a goose chase.
Figure out the average diameter L x W x 1/2
multiply by Pi(3.14) that’s the length you cut. It will of course be
a tad small but you have to whack it on a mandrel anyway to shape it
so whack it a bit more and you can up the finished size to suit. This
is usually quicker than making it too big and having to cut it down
and resolder.
If you are using thick bezel stock you’d add its thickness to the
free length you cut. In the case of ‘really’ thick material add 1 1/2
to 2 times the thickness. The thicker it is the more you should bevel
the ends so they meet flush. If your ends are square you will have to
make a D shape in order to get a flush join which then means you have
to hammer it quite a bit to make it round(and perhaps over shoot your
desired size or rip open the solder joint… bummer)…easier to
bevel beforehand.