It is with great sadness I'd like to announce Dr. Hanneman passed away on December 12, 2020. His legacy will live on forever!
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 Post subject: Re: Preforming tips_Use a cabbing wheel or the lap
PostPosted: Sun Nov 08, 2020 4:21 am 
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glhays wrote:
You can only learn from the advice being given here.

I have always found you can ask for the moon but just because the GemGuide publishes that the industry believes Montana blue sapphire 1.00-1.69ct. stones should get you from 250-1,000 p/carat, you will need buyers at these rates. Yes if your one that purchased rough back before the market on a given species became highly sought after, and you do not need to let it go for less than what the few industry markets state. Then that someone can hold out for stated rates. For someone thinking they can run and get a 3 carat Montana blue sapphire tomorrow at a decent price(?) and go back and run it thru the 1 hour speed facet and then just turn around and sell it for $1500 is very unlikely. Randy, maybe as an experiment see if you can find that 3ct rough, cut it as fast as you can while still doing a decent job. Then offer it to Gene for $1000.00.

Back to the cutting, do you find yourself with the 100k spending more time on then the 3K outer? If so you may rethink going to 50-60k.
Or take Genes recommendations and go to 8k instead of the 3k, although you have already designated as 3K so that would be an investment into another lap.
.


I never said I get $1000 per ct for Montana, I said others do. Check out Earths Treasury website. I think he is one of the guys who have driven these crazy prices for Montana. Montana pricing is no longer in “The Guide” it was about 10 years ago, and back then prices were in the $200 t0 $350 per ct range.

You can use 8000 on the lap you previously charged with 3000. After a few stones the 3000 will cut like 8000 anyway. I mix both all the time.

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 Post subject: Re: Preforming tips_Use a cabbing wheel or the lap
PostPosted: Sun Nov 08, 2020 9:33 am 
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Precision Gem wrote:
You can use 8000 on the lap you previously charged with 3000. After a few stones the 3000 will cut like 8000 anyway. I mix both all the time.
Agreed. Usually I use 8k prepolish, but to move a large facet I apply some 3k, then clean off the swarf and any loose 3k for a finer finish, and if it needs help apply some 8k before going to 100k to polish. You can 'tune' the prepolish lap to do your bidding.

The preforming issue appears to be a matter of two different cutting approaches. 'Traditional' gem cutting, as described by Steve (1bwana1), depends crucially on an accurate preform to determine the shape and then facet placement is by eye. 'Meetpoint' faceting generates the shape by planned, sequential facet placement, so preforming becomes an optional prior step to remove surplus material and obvious flaws.


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 Post subject: Re: Preforming tips_Use a cabbing wheel or the lap
PostPosted: Sun Nov 08, 2020 3:45 pm 
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Duncan Miller wrote:
Precision Gem wrote:
You can use 8000 on the lap you previously charged with 3000. After a few stones the 3000 will cut like 8000 anyway. I mix both all the time.
Agreed. Usually I use 8k prepolish, but to move a large facet I apply some 3k, then clean off the swarf and any loose 3k for a finer finish, and if it needs help apply some 8k before going to 100k to polish. You can 'tune' the prepolish lap to do your bidding.

The preforming issue appears to be a matter of two different cutting approaches. 'Traditional' gem cutting, as described by Steve (1bwana1), depends crucially on an accurate preform to determine the shape and then facet placement is by eye. 'Meetpoint' faceting generates the shape by planned, sequential facet placement, so preforming becomes an optional prior step to remove surplus material and obvious flaws.

Agree as well, although some newer cutters I find are extremely fearful of the whole cross contamination scenarios. They really have not grasped that the hardnesses of each of the individual surfaces coming into contact play big parts into the equation. I have batt laps that I have intentionally loaded with 3 and 8k diamond as well as 8/14k. If needing more or less, just add the appropriate to the mix.
Agree as well with your take on the preforming debate completely, there isn't a wrong or right, one verses the other isn't going to break the bank these days.

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 Post subject: Re: Preforming tips_Use a cabbing wheel or the lap
PostPosted: Sun Nov 08, 2020 4:55 pm 
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Precision Gem wrote:
glhays wrote:
You can only learn from the advice being given here.

I have always found you can ask for the moon but just because the GemGuide publishes that the industry believes Montana blue sapphire 1.00-1.69ct. stones should get you from 250-1,000 p/carat, you will need buyers at these rates. Yes if your one that purchased rough back before the market on a given species became highly sought after, and you do not need to let it go for less than what the few industry markets state. Then that someone can hold out for stated rates. For someone thinking they can run and get a 3 carat Montana blue sapphire tomorrow at a decent price(?) and go back and run it thru the 1 hour speed facet and then just turn around and sell it for $1500 is very unlikely. Randy, maybe as an experiment see if you can find that 3ct rough, cut it as fast as you can while still doing a decent job. Then offer it to Gene for $1000.00.

Back to the cutting, do you find yourself with the 100k spending more time on then the 3K outer? If so you may rethink going to 50-60k.
Or take Genes recommendations and go to 8k instead of the 3k, although you have already designated as 3K so that would be an investment into another lap.
.


I never said I get $1000 per ct for Montana, I said others do. Check out Earths Treasury website. I think he is one of the guys who have driven these crazy prices for Montana. Montana pricing is no longer in “The Guide” it was about 10 years ago, and back then prices were in the $200 t0 $350 per ct range.

You can use 8000 on the lap you previously charged with 3000. After a few stones the 3000 will cut like 8000 anyway. I mix both all the time.

Gene, I stand corrected you are correct, what I stated was on blue sapphire generally not Montana specifically.
As far as Hapeman's website pricing, it is just that an asking price or as you mentioned just a marketing plan (do not take out of context here). I also see their category of sapphire overwhelming the largest category and the majority marked as "new". I guess one can take that like the glass half full or half empty. Either they cut and sell an overwhelming number or they have an overwhelming amount of stagnant inventory, no way to know from a e-commerce site. JMO....

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 Post subject: Re: Preforming tips_Use a cabbing wheel or the lap
PostPosted: Sun Nov 08, 2020 6:12 pm 
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Hi Steve,

I am cutting on a Polymetric Scintillator like Glhays.

I think I need to try to break myself of looking too often and trust the machine a little more.

I started cutting on a Facetron I bought from Norm Jarvi 26 yrs ago but could never get any consistency on that machine. It could have been me being new or the machine was out a little bit-I don't know but that's where I started having to look a lot because I wasn't able to trust the machine.

I know a lot of people have great luck with Facetrons, like Steve, but I couldn't get it to work for me. I went from there to an used Ultra Tech that was fairly good but had to quit faceting after a few yrs and sold it. Then when I started back in I bought a Fac-ette but unfortunately the brand new machine had issues and I didn't realize it. I got it fixed at the factory and they said the assembly that slipped over the base was machined oval and not round and they replaced it and I sold the machine.
It had a lot of great features and some people like Gene have gotten one that worked good.

I bought the Scintillator 4 yrs ago when I started cutting again and it seems to be very accurate for me.

Again, I am not saying one machine is better than the other--I just ended getting machines that either were messed up or I couldn't get them to work for ME.

I would like to know Glhays procedure for cutting the table at 0* on his Scintillator as that was one feature I really like about the Fac-ette.

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 Post subject: Re: Preforming tips_Use a cabbing wheel or the lap
PostPosted: Sun Nov 08, 2020 6:17 pm 
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One last question on time savings on cutting a SRB.

When cutting the pavilion do you cut the 90* girdle facets all around and then cut in the 16 breaks to CP?

That is what I do but sometimes it seems too time consuming and I think I should cut 4 of 90* facets in to make sure the stone is centered pretty well and then cut the breaks in to CP as this would speed up the cutting.

I haven't tried it as I was taught to cut all the 90* facets in first but it is something I have been thinking about doing.

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 Post subject: Re: Preforming tips_Use a cabbing wheel or the lap
PostPosted: Sun Nov 08, 2020 7:00 pm 
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deanins wrote:
One last question on time savings on cutting a SRB.

When cutting the pavilion do you cut the 90* girdle facets all around and then cut in the 16 breaks to CP?

That is what I do but sometimes it seems too time consuming and I think I should cut 4 of 90* facets in to make sure the stone is centered pretty well and then cut the breaks in to CP as this would speed up the cutting.

I haven't tried it as I was taught to cut all the 90* facets in first but it is something I have been thinking about doing.

What you propose I would think will cause more time as you would be going back and forth on mast height adjustments.

Are you having issues with girdling alignment and trying to find a resolution or just looking for time saving tips?

Cut all the facets in one direction of the index wheel, then reverse the direction of cutting back to the beginning on the same mast height.
I know Zane quite well at Poly-Metric and no ill feelings to his machining tolerances, but the quill assemblies on the scintillators and index gears are not always as accurate as they can be.

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 Post subject: Re: Preforming tips_Use a cabbing wheel or the lap
PostPosted: Sun Nov 08, 2020 7:49 pm 
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deanins wrote:
Hi Steve,

I am cutting on a Polymetric Scintillator like Glhays.

I think I need to try to break myself of looking too often and trust the machine a little more.

I started cutting on a Facetron I bought from Norm Jarvi 26 yrs ago but could never get any consistency on that machine. It could have been me being new or the machine was out a little bit-I don't know but that's where I started having to look a lot because I wasn't able to trust the machine.

I would like to know Glhays procedure for cutting the table at 0* on his Scintillator as that was one feature I really like about the Fac-ette.


Like I said in the earlier post why are you not trusting the machine?

Also what model do you own is it the "88"?

Cutting the table on a Scintillator is probably no different to any machine that has the mast height and angle availability to cut at 0 degrees to the lap. Just set the quill to zero, move the mast assembly in towards the lap usually as far as it will travel. I holding the dop or stone as close as possible to the lap while applying a little pressure against the stop to hold the quill at zero and lowering the mast slightly downward to the spinning lap works best for me. It can be a little bit like the game of twistor with your arms and hands a bit. I typically do not have much material to remove to cut in the tables in or to realign the temp table if needed. This also means if any of star facets need some fudging the dop hasn't been removed where keyed dops on the other machines it is not an issue here. In the pic the dop setup is from the Jang with a custom adapter to work in the poly.

Attachment:
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 Post subject: Re: Preforming tips_Use a cabbing wheel or the lap
PostPosted: Sun Nov 08, 2020 10:44 pm 
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The key to the Facetron is to get it properly dialed in which is really easy. Then it is a matter of learning to properly use the dial indicator. It will be very accurate then. It is valuable to set up the machine to use it as a soft stop/hard stop combo to avoid any flex in the machine. properly used the dial indicator and protractor are used as measuring devices, not used to set angles or cutting depths. It works very fast like that.

My machine has some custom modifications that provide additional flexibility and precision. This includes the ability to cut at partial indexes. My 96 Index gear actually has 192 indexes.

I have some other custom Facetron machines for special purposes as well. One is a real hard stop style machine. Once you set the angle and depth you can just cut to the stop. No flex, very accurate, very fast. I use it for runs of calibrated stones. For single stone cutting the standard machine is actually faster.

below are some of my custom Facetron machines and accessories.


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 Post subject: Re: Preforming tips_Use a cabbing wheel or the lap
PostPosted: Mon Nov 09, 2020 12:55 am 
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Steve, is that a motorized girdling performer out front in the pic? Very nice tool toys!

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 Post subject: Re: Preforming tips_Use a cabbing wheel or the lap
PostPosted: Mon Nov 09, 2020 11:04 am 
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Greg,

Yes it is the performer. It is currently running with the Graves motor. But Jeff gave me a special motor and switch to install in the base. That has adjustable speed and direction so I should just install it. It has adjustable L/W ( genius way of doing this with a fulcrum) , and height adjustments to control size. Just put the dop in, turn it on and take the stone out when it stops cutting. Accurate to within 0.05 mm.

The hard stop machine can cut to the stop automatically so all I have to do is change the indexes to cut.

They are both on the same base so when I am cutting runs of calibrated stones I can preform and cut the tiers while another stone is performing. It at least double my productivity at that machine. But since the hard stop machine can cut facets by itself I can also be cutting on my regular machine.

Simultaneous preform and girdle facets on one machine, mains on the other machine. Since it is so easy to set the machines up with matching dop key alignments the dops transfer seamlessly between machines.


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 Post subject: Re: Preforming tips_Use a cabbing wheel or the lap
PostPosted: Mon Nov 09, 2020 4:03 pm 
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Steve,
Very nice setup. I have had several Graves preforming setups over the years on various setups for automation, non with their motor though. Just the $5.95 kits adapted, but then I went BSC and opted for a Cadillac of pre-formers called a Jang 801. :smt028

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 Post subject: Re: Preforming tips_Use a cabbing wheel or the lap
PostPosted: Mon Jan 04, 2021 7:26 am 
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Precision Gem wrote:

I see the same thing with lab created stones. Same material, some are getting $175 per ct, others 70 per ct.

As far as buying rough wisely, a cheap junk piece of rough can only at best result in a perfectly cut cheap stone.


Are people really buying lab stones for $70 pet ct?


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 Post subject: Re: Preforming tips_Use a cabbing wheel or the lap
PostPosted: Mon Jan 04, 2021 12:06 pm 
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Airscape wrote:
Precision Gem wrote:

Are people really buying lab stones for $70 pet ct?



Yes, and much more. Lab grown colored stones, like natural stones, have a wide range of pricing. Some methods can produce stones very inexpensively and fast. Other methods take a long time to grow the stones, and are expensive.

Generally I find that the slow growth methods more accurately reproduce the natural process, and the stones look more like natural stones in color, texture, and inclusions.

Here are some links:

https://fireandbrilliance.com/collectio ... e-sapphire

https://www.miadonna.com/pages/lab-grown-gemstones


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 Post subject: Re: Preforming tips_Use a cabbing wheel or the lap
PostPosted: Mon Jan 04, 2021 4:08 pm 
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After reviewing those sites and the price per carat their asking for Chatham material, I am glad I have sat on the crystals we have picked up over the years. The one site I do not see the specific synthetic they are selling just tradename of the species variety. Good for them if their getting these prices, which if you have that client base who appreciate the value of the look of a gemstone, it doesn't matter if its natural or a synthetic counter-part.

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