CAD Settings design

Dear Ganoksin Members,

I am designing my fist setting with CAD. for a 3X5 mm oval gem. If my
prongs are 0.6 mm in diameter (is that appropriate), when figuring
out where I want to place them in relation to the edge of the girdle
of the gem. I am wondering how much they should intersect the gem in
the design. How much of the prong thickness is removed at that point
(from the girdle and up) where the prong will bend over on to the
crown.

Thanks, Bruce

I am designing my fist setting with CAD. for a 3X5 mm oval gem. If
my prongs are 0.6 mm in diameter (is that appropriate), 

0.6 mm is too thin

Leonid Surpin.

About the same as for a hand fabricated setting… 30% to 40% cut
works well most of the time for me.

You might want to re-think cutting the bearings in the model, most
setters are pretty good at that. Even with ‘perfect cut’ stones and
pre-notched bearings I’ll slightly re-cut them.

0.6mm might be a little small on the model, remember the finishing
losses are higher on a milled or grown piece than a metal fabricated
one. At least for milling there are definite limits to what is
possible in terms of very small details dictated by the cutting bit.
A tappered bit can have an almost 0.02mm tip diameter but cuts
tappers, while a 0.1mm straight bit won’t last long.

Down the rabbit hole time… a model accurate to 4 decimal places
has no meaning nor reality.

Jeff
http://www.gmavt.net/~jdemand

Dear Bruce,

I am making 0.8mm in diameter and 0.2 mm above girdle. Keep in mind
that, that you can take off gold later but you can not put on
easily.

Regards,
Tusif Ahmad

when figuring out where I want to place them in relation to the
edge of the girdle of the gem. I am wondering how much they should
intersect the gem in

About 1/2 the prong or so…They can always be pulled back a bit.