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Polishing with diamond
Faceting has been an on and off hobby of mine since 1978, but since retiring a few years ago it became fulltime.
I decided to try my hand at competition faceting and joined the Ozzy facetors guild a few years back and entered their annual four stone comp. Not being a beginner I entered their intermediate section.
My score was very poor and I averaged in the low 80s, with one score as low as 72. Pathetic really and a lot of work to be done on my part if I was ever going to be any good.
A lot of my lost points was to do with polish and scratches and I’ve spent a lot of time refining my skills in that area.This year I’ve come equal first in the US Masters with 100 points and scored 296.7 in the International Faceting Challenge, 5th place. That put me between James Clark and Jack Freeman, 4th and 6th.
My polishing technique is more of a discovery than a refined art….I don’t turn the machine on and wipe the facet over a stationary lap. Sounds like its going to take forever to polish a facet, but it’s quite quick.
Well quick in the sense were not trying to knock this stone over on a Saturday afternoon.
I move the stone from side to side as usual and move the lap slightly by hand, you will be able to see the areas that are not perfectly polished. Because you have total control you can start playing around with the cheater and mast screw to squeeze into the facet corners that need finishing off.Happy polishing.
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20 Replies
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Congratulations Frank. Do you cut with a Aussie machine?
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This is priceless! Thank you Frank!
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Thanks for the complement.
I worked in manufacturing/engineering and enjoyed the challenge in making my own machines.
Copied the features I liked the best from the machines on the market, though haven’t tried to fit a digital protractor. Bit over my head. -
I like it. The index gear, is something that was made for you or did you buy one?
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I bought the index gear as a spare part from one of the manufacturers suppliers. That and the V dops are the only parts I’ve bought coming from faceting machine manufacturers.
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You should write an article and submit it to our editor on the process of building the machine. I believe there are others that would enjoy hearing about the build. I do not believe the idea was to save money but rather to build a better machine knowing what machine shops charge. I like the idea of the removable digital angle gauge rather than a protractor. I do not see any problem not having one built into the machine. If it ever fails you can cheaply replace it.
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Thanks for the complement on the machine David.
Yes, your right it wasn’t anything to do with the money, but the enjoyment of making it and producing a good stone from it. It would have been a lot cheaper to have bought a good second hand one.
The protractors are not light and have to come off, but you don’t need them once setup. You rest the stone on the lap and adjust the mast height till you have the required angle. Set the dial gauge and now that position on the gauge is that angle.
I’ll have a think about righting an article on building the machine. I’ve got a full set of dimensioned CAD drawings for every component and don’t mind giving them to anyone who wants to have a go.
It also has a very accurate means of recording the position of every facet. -
@Frankwood… That is a most impressive piece of work. I agree that you should write up your build. Thanks for sharing.
Happy Faceting,
John
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The subject seems to have shifted from polishing with diamond to making faceting machines.
if I was to build a new mast and faceting head assembly from scratch I would base it on Robert Slaters.
https://www.jrobertslater.com/homebuilt-faceting-machine/
His machine is easier to make than mine and the digital angle encoder he has on it is a huge plus and something I want.
But for the moment I’m busy making a concave cutting attachment, so the angle encoder will have to wait. -
It is common for threads on any forum to divert to another subject. This one because you are one of the few that has built his own machine. On the subject of differences on a square mast vs round, I prefer the round quick release type of my Facetron has vs the square crank type of the Ultra-tec I also own. If a square type mast is made correctly inherently it should be more accurate. You always see commercial milling machines with square mast for this reason. For commercial cutting speed is important to produce more stones so a quick release is preferred, at least by me. On a faceting machine I really do not see any difference in the accuracy of either one if they are well made.
Concave cutting? Not for me. No way do I have the patience for doing it but I like the results.
As far as diamond polishing, all my competition quartz stones were polished with diamond where I could read the grease and know what needs more work. Never had any points deducted for polish. For the cutting I now do I now use cerium and a matrix lap after a 3,000 prepolish on a batt. When I was commercial cutting years ago I polished and sold many amethyst, citrine and smokey quartz stones with a diamond 14,000 polish on a tin lap after cutting on a 600 grit lap. That was before the Batt lap which is a harder tin lap and better. This forum is mainly for competition cutting so it is not a technique that would be used. I have not found anything diamond will not polish if one uses the right technique.
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DavidEchol
First up , congratulations on another success . Your record in competition faceting is superb.
On the subject of polishing I use similar to you – 3000 on Battlap for prepolish and cerium on Matrix lap for polish . But I only use this combination on Quartz or stones of a similar hardness . Surely you use another combination on harder stones .
John -
John I have not competed in many years. Sorry for the confusion. I thought about trying again this year but it is not going to happen, too rusty. I am having trouble seeing those tiny facets on this years Grandmaster stone. You are correct that Matrix and cerium is only used on quartz or similar material. I have a lot of Bytownite I bought by the pound years ago and it polishes nicely with cerium on Matrix as well. Bytownite cuts and polishes and great looking stone. Diamond, 50,000, after 3,000 prepolish on a Batt, for everything else. I now use the good old red cerium. On a Matrix and with red cerium it only takes a small amount which lessens the one fault of oxides, the mess. After seeing Aussies polish opal with red cerium on youtube I quit using the more expensive French cerium. Red works faster as well.
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I should mention that the last year I competed was on The Australian International Challenge was in 2014. Ironically on the American team of five I placed 3rd behind James Clark 1st, Jack Freeman 2nd and it is good to hear that they are still going strong. The American team that year was 2nd behind those Aussies. For those that are not familiar with that contest it is a team competition of 5 of the best cutters in that country with a 3 stone entry that draws the best cutters from around the world. Our competition now draws cutters worldwide as well which was not the case before 2014. A few maybe but not like it is now which is good for the USFG.
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Just to add a bit more to David’s comments on the Australian international challenge. It is both a team and individual competition, you don’t have to be part of any team to compete.
There are five stones in the competition and your score is based on the three highest. You don’t have to cut the five stones, I didn’t bother, as long as you cut at least three.
You can also compete in their national competition, which attracts facetors from around the world. That’s a four stone competition, with the entrants being judged on the total of the four stones entered. -
Frank I am glad you updated the rules as they now apply. Things have changed since I competed in 2014. The one thing I bet that has not changed is the standard of the judges. They are tough.
Also, congratulations on your 100 score in the USFG Masters competition. You tied with Hu Naiyin of Taiwan who also scored a 100. Cannot get any better than that.
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