Premaster differences

[Rick_Brooker]

There are big differences in the angles in the premaster stone when you compare the sheet in the newsletter and the one in the competition section? Has anyone noticed this? The guide in the competition section doesn’t work. I tried and it doesn’t cut right.

[Rick_Brooker]

The diagram doesn’t seem to follow the original drawings on facet diagrams.org.
http://www.facetdiagrams.org/database/files/pc07152.html

[Glenn]

From Facebook, I downloaded the Master Stone Competition diagram. I wanted to practice on it. The diagram is completely messed up! Missing facet information for 12, 13, 14, 15, & 16. The numbering is a total waste of time. I used my Gem Cut Studio to recreate the design, so I don’t know if the angle in the printed diagram were right or wrong.

[Alan Balmer]

According to a recent FB post, the diagrams have been corrected on the website and there is a corrected newsletter available for download.

[Rick_Brooker]

I just checked the premaster diagram on the webpage. It is not correct. I have been able to cut the pavilion using Jim Perkins’s original diagram from facetdiagrams.org. The pavilion angles are wrong. The original diagram is kind of fuzzy on how big the corner girdle cuts should be. I just reversed steps 3 & 4 and cut them to look like the picture on the diagram and everything else matched up. Here are pictures of how it turned out.

• This reply was modified 2 years, 4 months ago by Rick_Brooker.

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[Rick_Brooker]

I wasn’t clear in the last post. When I said the pavilion angles are wrong, I mean the comp stone diagram angles are wrong. When you look at the original from facetdiagrams.org the pavilion angles are different but the crown angles are the same in the comp stone. I think someone transposed something when they took the original diagram and formatted it for the competition. The preform on the comp stone guide gives an exact location for the corner girdles but the original is a little fuzzy about sizing the corner. I think the added preform steps throws it off .

[Alan Balmer]

Competition designs can be and often are modified from the originals. I believe the Facebook announcement mentions that.

[Rick_Brooker]

I understand that changes will be made for competition purposes but have you actually tried to cut the design as posted? I have and if you you have cut it and it turned out OK then I would love to have talk further with you so I could see where I made any mistakes.

[fifthandgoal]

Let me take a minute to voice support of Rick’s pre-master pavilion concerns, incorporating the preform steps. In my quick test cut attempt, the pf1 cut (at 40.01) never truly gets overwritten/overcut. And I think that is the root cause of the issue here. The pf2 and P1 cuts all meet at a cullet points (unlike the diagram image) and the P2 cuts don’t make it more than half way up P1 before they meet at G1, G2 – as per the instructions. Again, I believe that the angle of the preform pf1 cuts are inhibiting the ‘layered’ intent of the pavilion’s original design?

Apologies if I am incorrect in this assumption, or if I failed to articulate the issues I’m having, but cutting this pavilion, specifically according the the sequence in the pre-master pdf, isn’t yielding me the desired outcome. Thanks much.

– Mike.

[fifthandgoal]

My apologies, I must have forgotten to shave yesterday. I borrows Occam’s razor and cleaned up today. Simply overcutting the P1 on the premaster diagram will resolve the issues I wrote about in my post. Cutting not only to a PCP, but down the cullet a bit, will overwrite the preform (pf1) cuts – then everything else falls into place.

Thanks, and enjoy.

– Mike.

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