joejansal
noticing nice landscape pebbles
Member since August 2009
Posts: 98
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Post by joejansal on Feb 25, 2017 12:57:10 GMT -5
hi all,
need expert input on reducing size of cabochons. I use core drills to make round cabs say a22mm core drill will produce a rough 18mm cab, my goal is to get a 16mm cab have tried all sizes of core drills to get me to the 16mm cab, the best so far is the 22mm core drill gets me to a rough 18mm then have to smooth and polish on my genie to 16mm finish. problem is to keep it perfectly round. I also have a gryphon diamond grinder I have the hardest time keeping it perfectly round you expert cabbers must have a few tricks to help me. need all the help I can get thank you joejan
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Post by rockjunquie on Feb 26, 2017 7:50:37 GMT -5
Since no one else is chiming in, I guess I'll throw in my 2 cents. It sounds like you are going to have to finish it freehand. I have never done this, but some people mount their dopstick on a drill to finish rounds. Maybe that's something to try.
ETA I see you posted the question elsewhere, as well. I hope you have good luck with it.
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Fossilman
Cave Dweller
Member since January 2009
Posts: 20,681
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Post by Fossilman on Feb 26, 2017 10:14:38 GMT -5
I free hand all my cabs......I guess you get use to doing it....Might have to try it that way and see....
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Post by parfive on Feb 26, 2017 14:54:47 GMT -5
No tricks req’d. Just draw a 16mm circle and learn to color outside the line. Ain’t rocket science.
Easiest shape to cab is round . . . dome never varies on any axis.
[Cab questions usually get more exposure when posted in the cab section.]
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Post by radio on Feb 26, 2017 16:31:12 GMT -5
On the rare occasion I have to do a calibrated round cab, I scribe the outline with an aluminum scribe, then cut to the line. I also have a complete complement of templates, so cut a little and check a LOT with a template.
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dbmyers
off to a rocking start
Member since June 2017
Posts: 4
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Post by dbmyers on Jun 25, 2017 6:32:01 GMT -5
I free hand all my cabs......I guess you get use to doing it....Might have to try it that way and see.... I learned back in high school, with small stones on dop sticks. When I came back to Lapidary years later, after retirement (3 years ago) I learned to do cabs freehand and I prefer that now, but it is pretty clear to me that a round cab is much easier to do on a dop stick. You just pick your angle of contact with the wheel and rotate the stick continuously, with out changing the angle.
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