Adjusting the Index when Stone falls off the Dop

[timothyhall]

I’mm looking for some guidance here. After cutting the first tier on the pavilion the stone fell of the dop a couple of times. The last time, I glued it back on with epoxy, trying to match up the impression in the wax. Turns out I was off and needed to adjust the index gear by 12 (e.g. index of 90 became index 78) in order to line up the existing pavilion facets. Now I have finished the pavilion, adjusting all indices in the diagram by negative 12 and am ready to cut the crown but need to adjust those angles also. My question is, do I adjust each index by the same negative 12 or, since the stone is turned over, do I adjust by positive 12 (e.e 90 becomes o6). I’m scratching my head over this and am not sure which way to go. Thanks for any help.

[Frankwood]

Cant see what difference it makes.

[Tom Mitchell]

Tim,

What machine do you have? If it is anything but Facetron, then take the dop out of the key so that it rotates freely. Then lower the facting head till the quill is parallel to your flattest lap or at the angle 90 degrees. Rest the stone on the lap and rotate it till you fill a flat spot. Then while holding the stone down on the flat spot, tighten it in the quill. You should be ready to go. But understand, that you only lined up the girdle facet in relation to the index position. It may still be slightly off based on its original position on the dop. so you will have to recut all of the facets you were working on before the stone came off.

Another thing to consider, is if you were using dop wax as your binding agent, when the stone came off there is a pretty clear impression of where the bond broke and with a little patience and a steady hand you can usually get it even closer to perfect. But you still need to recut everything you were working on.

Good luck.

Tom Mitchell

[Tom Mitchell]

If you are using a Facetron, you will need to loosen the securing nut for the quill to allow the quill to rotate freely then go through the same procedure as described above. Once you find the flat spot, tighten the nut up again. But remember to readjust the quill after you are finished back to the ZERO position or you will have problems with every stone you cut after that.

Tom Mitchell

[Tom Mitchell]

If you are using a Facetron, you will need to loosen the securing nut for the quill to allow the quill to rotate freely then go through the same procedure as described above. Once you find the flat spot, tighten the nut up again. But remember to readjust the quill after you are finished back to the ZERO position or you will have problems with every stone you cut after that.

Tom Mitchell

[timothyhall]

Thanks. Tom. Sorry for the delay. Yes, I have a Facetron so will follow those recommendations

[gemmakermz]

hey guys i don’t have much problems there. if i have dopped strickly with a really good green wax like i have gotten off ebay seller, and it breaks loose if i have a good pattern match as one of you said put a tiny drop of gap filler cyno(crazy glue i get from the hobby shop that wood frame model pane builders use. set it done on it it will give me time to make sure i’ve set it right the spray with setter/fixer and done, usually good but my have to tweak cheater a tiny bit. i dop to expected table with the smallest dop i think i can get away with and use a drop of cyno then build up a good supply of support wax to back it up. this helps hold better and also for transferring to cut table helps hold while transferring to wax on pavilion. i then use a warmup exacto to cut back support wax on table area and then hold onto the stone and pavilion dop and heat table in my alcohol flame and shear snap it off. i do make sure i get plenty good wax transfer so if in removing the table dop the pavilion dop come off i remove table dop and match wax pattern and then put drop of cyno and reseat and walla i’m ready to go.
gemmakermz@cs.com

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