Nuevo, no promises but we'll do our best! lol
Christopher,
It depends on the pavilion, let's say we have 2 types of pavilions on "standard" designs:
1. Knife edge culet, basically just a long, thin line in the centre of the stone.
In the roughing in stage, lets as an example say you use a 360 lap.
You grind until everything is in that nice little line, every facet "touches" that line.
Something like this:
Compare with this one which hasn't been cut deep enough, you can see not all facets are "meeting" that line, some are down right missing!
2. Culet, basically a centerpoint where all the "main" facets meet.
How to cut it varies, I like to cut in the break facets on the pavilion first
to a centerpoint. They would all make a sharp point on the stone, and no facet should look longer/shorter then the other under magnification.
I'm not sure this makes sense if your new, if I remember I'll take pics next time I facet a stone to show what I'm talking about. Pics can say more then a thousand words.
But it looks like I have some re-cuts first in line.
Connie, depending on what kind of motor maybe it can be replaced?
Frank,
I agree a good book is helpful. But these ratios is something I've never cared about, except to make out the size of the table.
