Forums Techniques, Tricks, and Tips Stone on Lap

  • Posted by wilbertfwebb on December 10, 2017 at 5:55 pm

    Never start the LAP rotation with the stone touching. Twice I’ve done this and when the angle of cut is down around 14 degrees there is a very good chance the stone will bite into the LAP and the GEM will be ruined or you will need to recut. I was one cut to go before the table and (Bang) my stone was touching when I started the rotation. If you look closely you I attempted to salvage the gem but the damage was too deep and the girdle cut still shows the damage.

    Bert Webb
    Sophia, N.C.

    wilbertfwebb replied 6 years, 7 months ago 2 Members · 2 Replies
  • 2 Replies
  • Alan Balmer

    December 11, 2017 at 8:24 pm

    Bert, which side of the lap are you cutting on? The rotation should always be in the direction the dop is pointing. In the reverse direction, it will certainly grab at low angles. Depending on the machine, it could actually cause damage to the hardware.

    \ dop
    _________> lap rotation

  • wilbertfwebb

    December 11, 2017 at 10:06 pm


    My eyes have just been opened. Thanks very much. I switch rotation often and I never gave it any thought that this caused my issue. 🙂


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