Forums General Discussion Master Class Single Stone

6 replies, 4 voices Last updated by Alan Balmer 3 years, 4 months ago
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    • #6989

      Ronald A Maitland
      Participant
      @ronaldamaitland

      Looking at the diagram for the master class single stone competition, several index settings are in decimal numbers. I have never seen this before. Does one round up/down, or use the cheater?

      Ron Maitland

    • #6998

      master1975
      Moderator
      @master1975

      The pavilion and crown angles are listed to the hundredth of a degree. The index settings are whole numbers.

    • #7007

      It is normal for the designs in the SSC to have angles listed in decimal to two decimal places. This is a result of the computer designs having this capability. You are expected to interpolate on your faceting machine to best approach this angle and cut all the facets in a tier to that consistent angle. If you do this well, the result will be a stone that will be judged based on the parameters in the judging manual. There is no means for the judge to measure angles to 1/100ths of a degree.

    • #7009

      Ronald A Maitland
      Participant
      @ronaldamaitland

      The crown tier C facets show indexes in decimal tenths.

      Ron

    • #7010

      Ronald A Maitland
      Participant
      @ronaldamaitland

      For anyone cutting this stone, I figure the correct C indexes to be; 5-19-29-43-53-67-77-92.

      Ron

    • #7011

      Ronald A Maitland
      Participant
      @ronaldamaitland

      Sorry. Last index should be 91.

      Ron

    • #7023

      Alan Balmer
      Keymaster
      @alanbalmer

      Hi, Ron. There seems to be a discrepancy between the design in the newsletter and the one on the website. I think the website version is correct (no fractional indexes). Click on “Competition” in the menu. No login required.

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