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 Post subject: Re: Tourmaline
PostPosted: Tue Apr 27, 2021 4:28 am 
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Your pan looks like the ones I had on the MDRs. Probably original.

Your solution should work fine too.


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 Post subject: Re: Tourmaline
PostPosted: Tue Apr 27, 2021 9:22 am 
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Alright cool.
I will take some pics as I go through the stone that way you guys can see how off it is. I'm going to try fixing anything I come across so I'll note what I did as well to fix the issues.


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 Post subject: Re: Tourmaline
PostPosted: Tue Apr 27, 2021 11:24 am 
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I re-cut the girdle. I measured it at 7.56 mm and 7.59 mm. Is this an acceptable tolerance? I'm going by feel and ear as to the depth.


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 Post subject: Re: Tourmaline
PostPosted: Tue Apr 27, 2021 11:53 am 
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I cut this facet back to 45 deg from 50. The step that formed was pretty parallel until it hit the girdle. So it's looking good now. I guess I had the screw too tight on the mast. Now that I'm barely tightening it it seems good. Operator error I guess lol :roll:


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 Post subject: Re: Tourmaline
PostPosted: Tue Apr 27, 2021 12:54 pm 
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Cut all 4 facets to a TCP, then check the girdle line and the meets. Use your eyes as you bring in each facet to the TCP, looking directly down at the point.

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 Post subject: Re: Tourmaline
PostPosted: Tue Apr 27, 2021 1:08 pm 
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glhays wrote:
Cut all 4 facets to a TCP, then check the girdle line and the meets. Use your eyes as you bring in each facet to the TCP, looking directly down at the point.

It looks good to me so far. I cut those main 4 to center and then split them. It still looks pretty good, I'm on 1200 now taking scratches out. I like it so far. I'm going to do a step once I get the scratches out and go to 3k to check the parallelism of the step to the girdle. If that's ok still, which it seems like it should be, I'm good to go I think.


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 Post subject: Re: Tourmaline
PostPosted: Tue Apr 27, 2021 3:57 pm 
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Sounds like you have dialed in. Fine tweaking can be done as you go and get more familiar with the machine and your toolset, as well as your own technics of cutting.

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 Post subject: Re: Tourmaline
PostPosted: Tue Apr 27, 2021 5:12 pm 
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j.mcgee_1985 wrote:
I re-cut the girdle. I measured it at 7.56 mm and 7.59 mm. Is this an acceptable tolerance? I'm going by feel and ear as to the depth.



GIA tolerance for girdle dimensions as excellent on round and squares is with 0.10 mm. Your 0.03 tolerance is way better than that.


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 Post subject: Re: Tourmaline
PostPosted: Tue Apr 27, 2021 10:11 pm 
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1bwana1 wrote:
j.mcgee_1985 wrote:
I re-cut the girdle. I measured it at 7.56 mm and 7.59 mm. Is this an acceptable tolerance? I'm going by feel and ear as to the depth.



GIA tolerance for girdle dimensions as excellent on round and squares is with 0.10 mm. Your 0.03 tolerance is way better than that.


Awesome, thanks Greg!


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 Post subject: Re: Tourmaline
PostPosted: Tue Apr 27, 2021 10:35 pm 
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Gdhayes is Greg.

I am Steve


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 Post subject: Re: Tourmaline
PostPosted: Wed Apr 28, 2021 4:13 pm 
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Sorry Steve I looked at the wrong post.
I got the steps to line up almost perfect, but I didn't polish it well enough and wasn't sure if I wanted to leave or cut the inclusions. Looks like there's some pitting as well so I'm going to completely recut it. I totally forgot this doesn't have a light and I tried basically everything I have and nothing was working it took like 4x longer than normal to get the steps bc I couldn't see them well enough.
I'm going to recut later but at least the machine is good. A well positioned light is the final thing.


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 Post subject: Re: Tourmaline
PostPosted: Wed Apr 28, 2021 5:52 pm 
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I always have 4 lights going when I cut. As you have discovered having good visibility is key to both good results, and speed.

1.) Good basic room Light. Full spectrum daylight balanced.

2.) A full spectrum daylight balanced bulb task light that is positioned to lite the lap on the machine. This should have a good hood on it. Place it on the opposite side of the machine from where you sit. Position the hood to lite the lap, but make sure that the hood keeps light from hitting your eyes directly. This eliminates glare from bothering your eyes.

3. & 4.) This is a two light task light. The inner light is an incandescent bulb. The outer ring light is fluorescent. This is setup so that it can be positioned above and behind my head, giving me a direct reflection when the quill is positioned in the most comfortable position to inspect a stone. I can turn all the lights on (most of the time), or use soft fluorescent, or hard incandescent light to reflect off a surface.

Here is a link to this light fixture:https://www.amazon.com/Modern-Architect-Style-Adjustable-Office/dp/B007LL00C4

Using this system I always have excellent light for seeing the cutting, and inspecting polish, meet points, or inclusions. It also allows me to see the stone in any of the common color temperatures when needed.

This is a flexible and comfortable lighting setup. It really helps achieve excellent results, and reduces fatigue while cutting.


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 Post subject: Re: Tourmaline
PostPosted: Thu Apr 29, 2021 2:10 pm 
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Awesome thanks Steve, that's exactly what I need. The light I have is bright but won't sit over the top of the stone. I like your setup, I'm going to try and copy that.
I keep having problems with polish right now. Going from 600 to 1600 I'm getting all manner of results. Perfect high polish on one facet, complete doodoo on the next. Scaling, pitting, scratches.. I don't understand. Maybe it's mislabeled rather than 1600 maybe 16k? So far I'm just going from 600 to 1600 back and forth trying to figure this out. Maybe I'll go 600 to 3k next to see if it polishes different.


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 Post subject: Re: Tourmaline
PostPosted: Thu Apr 29, 2021 2:30 pm 
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What kind of 3k? Topper, powder, paste?

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 Post subject: Re: Tourmaline
PostPosted: Thu Apr 29, 2021 3:32 pm 
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I was just looking them up. Graves dyna discs, I have a 600 that's pretty used, a new 1600 that I just looked up to make sure it was a 1600, and a few new 3k's. I think I just need to learn how to use them. The polish off the 1600 was really high, I use a 20x loupe and I couldn't see any scratches and was getting blinded when the facet lit up. I think they just polish way way better than what I'm used to. Normally I cut with 1200 electro plate diamond and it isn't polished at all. I don't see a polish until 3k normally with the electro plate laps, and it isn't anything compared to what that 1600 did.
What is a good speed to cut on? Polish on? I've been hovering around 700 rpm for cutting and 1100 rpm for polish with the dyna disc laps.


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