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 Post subject: altering angles when changing the L\W ratio of a diagram.
PostPosted: Wed Dec 02, 2020 10:10 am 
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Posts: 186
Is there any simple method \formula to alter the angles relatively to the difference between the diagram used and the desired L\W ?
for example, lets say I started to cut a stone, measured it ,preformed it and decide on a rectangular shape\oval with a 1.3 ratio
then I cut an even girdle, start the mains, but had issues. inclusions that need to be removed, fracture that spread ,or any other reason that made me want to change the ratio.
what is the most practical way for alter the ratio and get good meets?
for now I am just using a computer software, sometimes it requires also to alter the indexs, depends on how big is the change. I would prefer a more practical way to do this on the go ,if there is any.
Thanks!


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 Post subject: Re: altering angles when changing the L\W ratio of a diagram
PostPosted: Wed Dec 02, 2020 12:39 pm 
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Hey Dor, I hope all continues to go well for you during these strange times.

Yes there is a way to develop a method so that you have flexibility and freedom to alter the outlines, patterns, and L/W/H ratios on the fly.

However it is not a push button solution. One should develop the capacity to look at a cut, and cut it. This is the problem with cutting using existing diagrams like a cookbook.

There are some simple relationships and rules that you need to understand that govern creating the size, shape, symmetry and positions of facets. These simple understandings are applicable to any shape, pattern and proportion of a stone.

I think I could easily get you going in the right direction in this regard if you were local and I could sit with you. You and I have worked well together on some other things so I am willing to make a special effort. I think we could also get there using a Zoom meeting and software like Gem Cut Studio. It is particularly easy using a Facetron machine which I know you are cutting with.

I have developed and printed a Gem Cutters Notebook for my students that helps you easily keep track of the indexes and angles using my system and nomenclature.

If you would like help in this regard, let me know.

Steve


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 Post subject: Re: altering angles when changing the L\W ratio of a diagram
PostPosted: Wed Dec 02, 2020 1:53 pm 
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1bwana1 wrote:
Hey Dor, I hope all continues to go well for you during these strange times.

Yes there is a way to develop a method so that you have flexibility and freedom to alter the outlines, patterns, and L/W/H ratios on the fly.

However it is not a push button solution. One should develop the capacity to look at a cut, and cut it. This is the problem with cutting using existing diagrams like a cookbook.

There are some simple relationships and rules that you need to understand that govern creating the size, shape, symmetry and positions of facets. These simple understandings are applicable to any shape, pattern and proportion of a stone.

I think I could easily get you going in the right direction in this regard if you were local and I could sit with you. You and I have worked well together on some other things so I am willing to make a special effort. I think we could also get there using a Zoom meeting and software like Gem Cut Studio. It is particularly easy using a Facetron machine which I know you are cutting with.

I have developed and printed a Gem Cutters Notebook for my students that helps you easily keep track of the indexes and angles using my system and nomenclature.

If you would like help in this regard, let me know.

Steve


Hi Steve, Thank you so much for the offer to guidance,we will talk about it in pm ,see how it can be done over the zoom. it can be fun to try :D
I agree that it's a very different thing to cut a stone to fit a diagram vs to know how to cut gems. maximize weight,dealing with inclusions,etc
but one can also do both .combined.
some of the best cutters in the world are using computers and technology to their advantage using diagrams as a tool to fit the stone they cut,and yet producing great stones with excelent recovery.
in my case , when I am changing the diagram ratio in the computer , I am getting a theoretical plan of a perfectly cut stone,with perfect meets,but can I really cut it like that? consider that my machine is bearly can be acurate to 0.1 of a degree, is it perfectly aligned? is the lap 100% stright? even the caliper which i use to measure the stone to fit the diagram,is not 100% acurate.
and of cuourse the human factor ,most importently. 0.1 degree error here+ 0.1mm error there, and the meets are off.


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 Post subject: Re: altering angles when changing the L\W ratio of a diagram
PostPosted: Wed Dec 02, 2020 3:22 pm 
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Joined: Thu May 12, 2016 2:18 am
Posts: 1098
Dor wrote:
1bwana1 wrote:
Hey Dor, I hope all continues to go well for you during these strange times.

Yes there is a way to develop a method so that you have flexibility and freedom to alter the outlines, patterns, and L/W/H ratios on the fly.

However it is not a push button solution. One should develop the capacity to look at a cut, and cut it. This is the problem with cutting using existing diagrams like a cookbook.

There are some simple relationships and rules that you need to understand that govern creating the size, shape, symmetry and positions of facets. These simple understandings are applicable to any shape, pattern and proportion of a stone.

I think I could easily get you going in the right direction in this regard if you were local and I could sit with you. You and I have worked well together on some other things so I am willing to make a special effort. I think we could also get there using a Zoom meeting and software like Gem Cut Studio. It is particularly easy using a Facetron machine which I know you are cutting with.

I have developed and printed a Gem Cutters Notebook for my students that helps you easily keep track of the indexes and angles using my system and nomenclature.

If you would like help in this regard, let me know.

Steve


Hi Steve, Thank you so much for the offer to guidance,we will talk about it in pm ,see how it can be done over the zoom. it can be fun to try :D
I agree that it's a very different thing to cut a stone to fit a diagram vs to know how to cut gems. maximize weight,dealing with inclusions,etc
but one can also do both .combined.
some of the best cutters in the world are using computers and technology to their advantage using diagrams as a tool to fit the stone they cut,and yet producing great stones with excelent recovery.
in my case , when I am changing the diagram ratio in the computer , I am getting a theoretical plan of a perfectly cut stone,with perfect meets,but can I really cut it like that? consider that my machine is bearly can be acurate to 0.1 of a degree, is it perfectly aligned? is the lap 100% stright? even the caliper which i use to measure the stone to fit the diagram,is not 100% acurate.
and of cuourse the human factor ,most importently. 0.1 degree error here+ 0.1mm error there, and the meets are off.



Yes, there are Sarin (and other brand) analysing machines that can help you decide the best orientation of the rough, where to saw, how to preform, and even actually give you a facet diagram. There are machines that can take these diagrams and cut the stones too. But the machines for actual faceting are only really working on mass production calibrated stones. The yields there are not really that optimal.

The one off larger and more valuable stones will still be cut on a faceting machine with an expert cutter.

There is no machine that can cut perfect meets by the numbers. You will always need to walk the meets in the final little bit. Usually during the final pre polish step.

I have a custom made super heavy duty hard stop faceting machine with absolutely zero flex in it and still the eye and hand are better.


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