Forums Techniques, Tricks, and Tips Adjusting the Index when Stone falls off the Dop

4 replies, 3 voices Last updated by Tom Mitchell 2 weeks, 2 days ago
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  • #6841

    timothyhall
    Participant
    @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.

    #6843

    Frankwood
    Participant
    @Frankwood

    Cant see what difference it makes.

    #6849

    Tom Mitchell
    Keymaster
    @tommitchell

    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

    #6850

    Tom Mitchell
    Keymaster
    @tommitchell

    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

    #6851

    Tom Mitchell
    Keymaster
    @tommitchell

    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

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