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 Post subject: Ultra Tec opinions
PostPosted: Sun Oct 28, 2018 4:50 pm 
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Ultra Tec’s current price list shows that the V5 can be ordered without the digital angle gauge. No doubt there can be more precision with digital, but I’ve always had nice results rounding off to tenths when necessary for a vernier scale. From what I can tell, cutters in the diamond industry still commonly use the analog Goren tang for those spendy rocks. Is there a message in that? Being an old guy, I've observed so much of everything converted to digital for no apparent reasons other than less costly manufacturing and fresh marketing spin. Do you folks who have converted to the LED V5 find it truly worthwhile, or just a different way to reach an end result? I’m not trolling here, just pondering a new machine.


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 Post subject: Re: Ultra Tec opinions
PostPosted: Mon Oct 29, 2018 12:46 pm 
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What got my attention and raised questions about the change was John Dyer's hands-on review of the DAD.

http://www.ultratec-facet.com/PDFs/DYER ... w10-09.pdf


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 Post subject: Re: Ultra Tec opinions
PostPosted: Mon Oct 29, 2018 2:50 pm 
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It's good to see a review of a digital angle machine from someone as respected as John Dyer. He points out some of the advantages of having an accurate and repeatable readout to 0.01 degrees. The method of establishing a centerpoint, for example, I use on every stone.

I've seen too many experienced faceters dismiss digital with "No one needs that much accuracy".


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 Post subject: Re: Ultra Tec opinions
PostPosted: Mon Oct 29, 2018 6:04 pm 
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I have a polymetric 87 machine with a protractor, I honestly regret not saving more and buying a digital machine. So many designs these days use crazy fractional angle measurements... I can theoretically adjust to .05 of a degree, but I have trouble returning to that exact degree, leading to over or undercutting here or there. It's made my learning experience a pain. With that said, I know people who have protractor machines that are cutting competition grade stones or cutting for a living, it's just a matter of practice and experience. I do believe there's a bit more of a learning curve when trying to cut "precision" stones on a protractor machine, but that could just be my experience I can't speak for everyone.


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 Post subject: Re: Ultra Tec opinions
PostPosted: Mon Oct 29, 2018 10:13 pm 
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aaronllewellyn wrote:
... I can theoretically adjust to .05 of a degree, but I have trouble returning to that exact degree, leading to over or undercutting here or there....


From what I'm learning about digital, the "cut a little and look a lot" rule still applies. The ability to see two decimal points is not the panacea I had originally assumed because variables still exist.

Quoting Dyer....
"So far in my tests I have not been able to cut a gem without inspecting the meetpoints and still achieve meetpoints that are good enough to meet my standards. That is what I had hoped for but have not quite been able to achieve yet. This is not due to any shortcomings on the part of the DAD however. The reason for the lack of perfection in the meetpoints cut in this manner is that when I cut the way I press on the gem varies very slightly from time to time and this combined with a small amount of flex and some lap runout make for a very slight difference from one facet to another in depth of cut and the resulting meetpoint. While some might be happy with the results after some practice and using an exceptionally flat lap I still feel the need to inspect the results and improve them slightly by the cut and look method."


Before I got a dial gauge, I struggled and adjusted my technique to compensate for the machine. After the dial, the process changed and bit and I again had to adjust to the machine. No doubt I could be assimilated into the digital process, too, if it improved what I already do without adding to the hassle factor.


Another Dyer quote that got my attention….
“….Because my DAD angle reading is now so accurate I became more aware of the fact that none of my laps are perfectly flat and even slight amounts of machine flex are shown in the angle reading. As the machine is on and the facet is in contact with the moving lap the last digit on the display will flash numbers constantly as the lap turns.”


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 Post subject: Re: Ultra Tec opinions
PostPosted: Tue Oct 30, 2018 12:54 am 
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The Ultra Tec DAD is a nice-to-have and helps in producing more accurate meetpoints, but you still have to look at what you are doing. It does speed up cutting because you only have to look when the second decimal digit start flickering, and it is most useful for arriving at a precise initial meetpoint in meetpoint faceting. It has a contact buzzer which can be used as an initial stop indicator, but given the unevenness of my laps I found the chattering of the buzzer annoying, so I switched it off.


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 Post subject: Re: Ultra Tec opinions
PostPosted: Tue Oct 30, 2018 9:44 am 
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I think a pure "cut to numbers" method is not attainable at this point. Variations in laps, machine flex, force inputs by the operator, variations in water flow, and in electric currents affecting the pot, keep the accuracy level required from being achieved.

If you know your machine setup in can get you close enough to improve accuracy, and speed. You will still have to "walk in the meet points by eye. I find a dial preferable to a digital gauge. The jumping, flashing numbers just bother me a little. We will each have our preferences in this regard.


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 Post subject: Re: Ultra Tec opinions
PostPosted: Tue Oct 30, 2018 9:27 pm 
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For me, the benefit of the DAD is the time it saves me in setting and adjusting the angle, in watching the numbers count down (estimated time of arrival at the stop), and in adjusting my machine. The ability to see how uneven my most used laps have become is an added bonus!

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