November 13, 2019 at 3:38 am #5852
I have read a couple of books on faceting, (Sinkankas and Vargas among them) and cut about 8 stones on an Ultra Tec V5 w/ DAD.
One thing I have not come across is a way to quantify how good the meets on my stones are.
I use a 16x doublet loupe extensively to check my work, and now can get, typically, maybe 6 of 8 facets on a standard brilliant table to look pretty close to sharp at 16x, and the other two to look not as good, but not bad with, say, a quality 10x Hastings triplet.
Would the same 10x criterion that applies to “loupe clean” gem material in rough and cut stones also apply to meets?
What/where is the way to judge this discussed?
How good are meets likely to get before one runs up against machine limitations?November 13, 2019 at 1:14 pm #5853
I have always used a 10x loupe for competition cutting. It was good enough to be 3rd in the group of 5 cutters that finished 2nd in the 2014 Australian International Faceting Challenge. It is my understanding that the USFG competition is judged using 10X loupes. If I am wrong I am sure I will be corrected.
For fun cutting or commercial cutting making precise meets is overrated. I only check the first meet in a sequence and use my Facetron dial for the rest. With a hard stop machine one can just use their ear. With practice your meets will be good enough. No one other than yourself will notice or care how close the meets are if they are not visible to the naked eye. The material, color and shine are what is most important.
My advice for a new cutter is to not spend too much time on one stone trying to make it perfect. Get use to your machine and with time you meets will get better and better. I still keep the first stone I cut and it is still beautiful to me with all it’s near meets and scratches.November 13, 2019 at 8:31 pm #5855
Thanks for that.
Very far from what I would have thought….
That explains why the issue is not covered in any detailed way in the books…
BTW, what do you think of this:
I have seen posts where experienced faceters say “you’ll never get truly scratch-free stones using toppers for prepolish” .
I guess that means plan on buying expensive laps like $175 Crystalites….November 13, 2019 at 9:35 pm #5856
When I started faceting, many years ago, I bought those expensive Chrystalites. I did not get that many stones from them before they were wore out. Do not waste your money. Buy toppers, 600 and 260 along with a 6″ batt with 3000 grit diamond for prepolish. For fun cutting I go from a 600 topper to a tin, or batt with 14,000 diamond. That combination will polish everything including quartz. Later you can add another batt with 50,000 or 100,000 diamond but for just fun cutting 14,000 works just fine. Commercial cutting factories use 14,000 or larger grit. Later you can add other laps as you gain experience. I have no idea how many polishing laps I have but when I just sit down to finish a stone in a couple of hours it is 600 topper to 14,000 diamond.November 14, 2019 at 12:17 pm #5857
I should have mentioned that the 600 topper is new it will be a little rough so it needs to broken in. Use some corundum to break it in and smooth it out some or it will leave some scratches that will be hard to remove without a prepolish with 3,000 on a batt if you go to a 14,000 on batt method. The scratches will not or hard to be seen with a naked eye but noticeable with a loupe.November 16, 2019 at 5:06 pm #5863
I am in total agreement with everything @davidechols said above.
I have more laps that anyone should have. You’ll soon learn how each of your laps cut, which will change over time as the lap becomes more worn. For example I have an old 600# that cuts like an 800#, etc.
Regarding Toppers… With a good master lap, a quality topper will perform as well as a solid lap.
As David eluded to above, “breaking in” a new lap (solid or topper) is critical. I just use a junky piece of corrundum to knock off the higher pieces of diamond. Once the new disk is cutting a smooth surface, you are good to go. Another easy way to break in a new disk is to use it for preforming a piece of rough especially if the material is say quartz.
Meet points? A decent 10x loupe is good enough for judging, so it’s good enough for me. Practice makes “perfect”. However, as a beginner remember that the quality/accuracy of your crown meets (for example) is directly related to how well you’ve done the meets in pavilion. I’ll also often leave a row of meets a little short, as pre-polish/polishing will “bring them in”. It just takes a lot of practice.December 12, 2019 at 10:04 am #5922
Jude – you asked about judging competition stones. https://usfacetersguild.org/competition-2019-draft/ Not sure if you’ve seen this page yet, but I believe it has the details you seek.
As far as making all the meets perfect – some commercial stones are pretty nice looking even though the meets are atrocious…and they sell! Anything you cut will be by far and away superior to most commercial pieces…even if all your meets aren’t competition quality. Your motivation for cutting will dictate how much time you decide to put into each gem. IMO, if you cut each one to competition quality, you’ll spend a great deal of time frustrating yourself and you won’t cut many stones…and most of them will not meet your desired standards. If you cut like I do, hobbyist, you can pump out several very high quality stones each week with a minimum of time invested. Without close scrutiny (which people don’t do) there is almost no difference between your hobby pieces and your competition pieces.December 12, 2019 at 11:40 am #5923
What sells is type and quality of material, color, shine and last of all decent meets. With experience your meets will get better and better. IMHO it would be no fun starting out trying to make a perfect stone. There is a big difference between what we do at the USFG and commercial cutting. If one watches some of the youtube videos of commercial cutters turning out stone after stone in just a few minutes with inferior equipment than we have with really decent meets one can see what can be done with experience. The main thing a beginner should concentrate on is having fun and doing a few stones. I am still proud of my first stone with crappy meets, scratches and a mediocre shine. I qualified as a Master on this site and have been on the team at the Australian competition but I what I would call a master cutter is some of the commercial cutters that churn out stone after stone everyday quickly. They are truly masters without recognition. Competition cutting is not what I would call fun. I think of it as more of a challenge to see the best you can do.December 12, 2019 at 5:22 pm #5925
How good do meets have to be? It depends on what your goal is in cutting. If it’s for sale, looking good to the naked eye is sufficient. Polish is more important. If you’re cutting for competition, they should be close to perfect at 10X. If your goal is to be better than your previous effort, the sky’s the limit.December 18, 2019 at 2:55 am #5937
When I first started competition cutting in the Australian guild a few years back I got a shock at my results. Of the four stone comp. I had two stones marked in the 70s.
Since being semi-retired and looking to expand my hobbies, putting some time and effort into it wasn’t an issue and now I find it a great challenge. I also enter the US annual competition and very happy with my results in this year’s comp.
One of the pieces of equipment that has been a great help to me is the slider gauge. If setup and used correctly it can keep a record of the height of the faceting head on the mast, to a practical accuracy of 0.05mm.
This allows you to return to any facet as shown in the picture. To fix errors such as A and B without messing up facet alignments C.
As shown in the picture, its made to keep the machine head to a precise depth.
Attachments:You must be logged in to view attached files.December 18, 2019 at 3:00 am #5939
Forgot other pics.
Attachments:You must be logged in to view attached files.December 21, 2019 at 4:28 pm #5945
As far as toppers go, I mostly use throwaway toppers. The very worst money I have spent was on crystalite solid steel laps. From what I can tell, they are just solid laps with diamond plated on. They are wonderfully flat, but don’t last any longer than toppers.
You can get toppers very, very cheap. Don’t get adhesive backed ones, they are awful. The plain no adhesive backed ones I use run absolutely flat. Zero needle bounce. You just have to use them on a perfectly flat master lap. A completely worn out crystalite lap is a great master. A *lot* of the 2019 usfg competition stones were cut on $10 plated toppers, including mine.
As far as meets go, nobody but us cares about perfect meets, but if you aren’t going to cut precisely what’s the point? You can get stones cut really nicely in sri lanka with tight meets and good polish for a few bucks.December 22, 2019 at 12:20 pm #5946
I agree with everything you have said David except that the one thing we can do better than the sri lanka cutters without fretting over perfect meets for fun cutting is polish. Anyone with a loop can look at an Asian cut stone and see what is a terrible polish with multiple scratches. Also with practice one can quickly cut a stone with just as tight meets as the Asian cutters but with a far superior polish. I have had the comment from jewelers that my clear topaz stones shine better than the diamonds in their store. I leave precise meets only when competing which I have not done in a long time. The main point is to have fun cutting whether it is just the cutting or making a perfect stone every time.December 22, 2019 at 5:33 pm #5949
“A *lot* of the 2019 usfg competition stones were cut on $10 plated toppers”
I’m curious as to how you know that. Frankly, I don’t believe it, especially in the categories above Novice.December 22, 2019 at 5:57 pm #5951
I think a well-worn topper is another piece of trash while a well-worn steel lap is a treasure…
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