ThomasT
has rocks in the head
Member since June 2022
Posts: 591
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Post by ThomasT on Jun 18, 2022 12:57:45 GMT -5
Has anyone had experience using 3 Sintered Diamond wheels on a 6-wheel cabbing machine ... i.e., 80-grit, 220-grit and 325-grit?
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Post by stardiamond on Jun 18, 2022 13:18:17 GMT -5
I don't use sintered wheels. My understanding is that they last a long time and are not as aggressive as plated for the same grit. I have changed my process to do most of my work on two 80 grit wheels; one new and aggressive and one worn to take out the scratches from the first one and fine tune the grinding. My 220 hard and 280 soft get little wear. The 280 should be soft. Like the 600 and 1200 sanding wheels.
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gemfeller
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Post by gemfeller on Jun 18, 2022 16:45:02 GMT -5
Has anyone had experience using 3 Sintered Diamond wheels on a 6-wheel cabbing machine ... i.e., 80-grit, 220-grit and 325-grit? I run 2 metal core sintered on my Genie with no problem. I run a plated plastic core on the left side in between them as well. My guess is 3 sintered wouldn't be a problem on a Genie. Are your sintered wheels metal or plastic core? What machine do you have? Many cutters, me included, use a 60 grit sintered in place of an 80 grit plated because they cut about the same. Welcome to the Forum BTW!
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ThomasT
has rocks in the head
Member since June 2022
Posts: 591
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Post by ThomasT on Jun 18, 2022 17:24:13 GMT -5
One of our machines is a Genie and we have talked with the manufacturer that stated there is no problem running sintered wheels on one side. The question is really geared towards the use of the 325-grit sintered wheel in place of the 280-grit soft wheel. We are going thru the soft 280-grit Nova wheels too quickly since we are mainly polishing very hard agates, sapphires and rubies on that machine... I believe we can replace all three on the left side with sintered and go from the 325-grit sintered wheel on to the 600-grit Nova soft... any thoughts or experience using this process?
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Post by stardiamond on Jun 18, 2022 21:14:27 GMT -5
I wore out a lot of 280 soft using it as a grinding wheel. Now I use it as a sanding wheel and it lasts a lot longer. The 280 soft is attractive because it is easy to control and still aggressive. From doing a lot of work my control is improved. My shape is completed before I get to the 280.
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ThomasT
has rocks in the head
Member since June 2022
Posts: 591
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Post by ThomasT on Jun 19, 2022 16:29:36 GMT -5
All preforming and grinding operations are currently performed on sintered wheels down to 220-grit. My query is due to Soft wheels on all finer grits being an unavoidable recurring cost as the polishing corundum star stones with rutile requires some operator pressure on all grits of diamond to properly polish. This type material with the rutile titanium oxide needles likes to be fed some diamonds on all grits of processing to finish well.... The wondering here is has anyone experience with the process going directly from a 325-grit Hard wheel (sintered or any other) before progressing to the 600-grit Soft wheels and subsequent wheels on the hard 9+ stones? Best regards!
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Post by hummingbirdstones on Jun 19, 2022 20:51:10 GMT -5
All preforming and grinding operations are currently performed on sintered wheels down to 220-grit. My query is due to Soft wheels on all finer grits being an unavoidable recurring cost as the polishing corundum star stones with rutile requires some operator pressure on all grits of diamond to properly polish. This type material with the rutile titanium oxide needles likes to be fed some diamonds on all grits of processing to finish well.... The wondering here is has anyone experience with the process going directly from a 325-grit Hard wheel (sintered or any other) before progressing to the 600-grit Soft wheels and subsequent wheels on the hard 9+ stones? Best regards! I'm tagging Starguy for you to compare with his process. He cuts lots of star sapphires and they turn out beautiful.
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gemfeller
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Member since June 2011
Posts: 4,022
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Post by gemfeller on Jun 19, 2022 21:48:53 GMT -5
All preforming and grinding operations are currently performed on sintered wheels down to 220-grit. My query is due to Soft wheels on all finer grits being an unavoidable recurring cost as the polishing corundum star stones with rutile requires some operator pressure on all grits of diamond to properly polish. This type material with the rutile titanium oxide needles likes to be fed some diamonds on all grits of processing to finish well.... The wondering here is has anyone experience with the process going directly from a 325-grit Hard wheel (sintered or any other) before progressing to the 600-grit Soft wheels and subsequent wheels on the hard 9+ stones? Best regards! I used to cut a lot of corundum stars. I don't think Genie-type equipment is the best way to go about it except for initial shaping on hard wheels. I had most success using a slant-cabber similar to the kind now sold by HiTech Diamond hitechdiamond.com/products/slant-cabber-rock-mineral-model/ equipped with maple wood wheels using diamond paste. Crystallite Starlaps are the current lap of choice for that work. Just my opinion: I'm anxious to see what Starguy suggests. Graves Company (now somewhat unreliable in meeting customer needs) used to manufacture what it called Star Cups that attach to most slant or horizontal lap arbors. They consist of a small plastic device that holds small copper and lead cups that can be charged with diamond. I have one but have never used it but I think it would be great for sanding and polishing hard star stones.
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ThomasT
has rocks in the head
Member since June 2022
Posts: 591
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Post by ThomasT on Jun 20, 2022 13:07:01 GMT -5
Thank you all for tips on methods. We have had great results using our wheeled machines over the years on these stones. However, we are wondering has anyone had experience with the process going directly from a 325-grit Hard wheel (sintered or any other) before progressing to the 600-grit Soft wheels and subsequent wheels on the hard 9+ stones? Best regards!
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Post by stardiamond on Jun 20, 2022 13:45:03 GMT -5
An extra right side arbor for the Genie allows for more choices.
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ThomasT
has rocks in the head
Member since June 2022
Posts: 591
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Post by ThomasT on Jun 20, 2022 15:18:36 GMT -5
Thank you all for tips on methods. We have additional arbors. We have had great results using our wheeled machines over the years on these stones. However, we are wondering has anyone had experience with the process going directly from a 325-grit Hard wheel (sintered or any other) before progressing to the 600-grit Soft wheels and subsequent wheels on the hard 9+ stones? Best regards!
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Post by stardiamond on Jun 20, 2022 15:27:42 GMT -5
The purpose of the 600 soft is to remove fine scratches and prepare the stone for polishing. I don't think it matters if the 325 is hard or soft as long as there isn't flat spots.
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ThomasT
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Member since June 2022
Posts: 591
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Post by ThomasT on Jun 20, 2022 15:30:25 GMT -5
Thank you again. We are wondering has anyone had experience with the process going directly from a 325-grit Hard wheel (sintered or any other) before progressing to the 600-grit Soft wheels and subsequent wheels on the hard 9+ stones? Best regards!
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Post by Starguy on Jun 21, 2022 12:47:49 GMT -5
ThomasTI’ve got a 600 grit hard wheel that I love. It’s 6” diameter on one of my older arbors. It does a fine job of smoothing ridges and scratches left by the 220 hard wheel. It still cuts pretty fast and will leave flat spots but the stones transition nicely to 400 soft or 600 soft SiC expando-drums. It does a great job on smaller stones. I originally bought it for controlling cutting speed for star garnet and star sapphire. It does a great job of removing scratches and small pits from the surfaces. Lately, I’ve been using it before 280 grit soft then 600 soft to remove any remaining last scratches. I’ve been considering getting a 600 hard wheel to replace the 220 hard wheel on my CabKing 8v-1. Hope that helps. None of them are sintered, all electroplated but the 600 hard wheel still does minor stock removal nicely. Hope that helps.
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ThomasT
has rocks in the head
Member since June 2022
Posts: 591
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Post by ThomasT on Jun 21, 2022 14:44:43 GMT -5
Thank you very much for the update Starguy!
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ThomasT
has rocks in the head
Member since June 2022
Posts: 591
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Post by ThomasT on Jun 21, 2022 15:29:53 GMT -5
Our goal is to save some serious money over time using the sintered diamond wheels.
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Post by pauls on Jun 21, 2022 19:22:44 GMT -5
I do the heavy work on a 80 grit sintered, it has developed a few bumps over the years so leaves quite deep scratches that the soft wheels take a while to remove, I also have a 600 grit sintered that I use to remove the deep scratches which works but is also slow, yesterday the postie bought a brand new sintered 220 grit wheel which I am in the process of figuring how to fit it on the arbor. A couple of (my) home maintenance jobs have dropped into the schedule so bathroom exhaust fan gets moved to the top of the list, sigh. Ah well, thinking about cutting rocks while playing around with the bathroom makes the tedious go quicker.
I have been in the habit of shaping with the 80, removing scratches with 600, going to soft wheels shaping and removing flat spots with 220, then just progressing through the normal sequence. I always add a step of giving a finish polish with Tin oxide on felt as I feel it is a better polish than the 50000 soft gives.
Sintered wheels are expensive initially but if you can afford the cost they are much much more economical.
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ThomasT
has rocks in the head
Member since June 2022
Posts: 591
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Post by ThomasT on Jun 21, 2022 19:55:27 GMT -5
We are going to proceed to spin up the 325 grit sintered ... since its in hand anyways... and then go on to the various diamond soft wheels and polish/buffer wheels. We have to stay very careful to avoid subsurface face fracturing on the more valuable hard 9+ stones before going for the polish runs.
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Post by pauls on Jun 21, 2022 23:38:20 GMT -5
I'm glad you are aware of subsurface fracturing, it is a big issue when faceting but can certainly ruin your day when cabbing expensive rough. When faceting I do most of my cutting with 600, if I have a lot of material to remove I drop back to 220 but stop well before I am anywhere near the final size and move to 600. A lot has been written and talked about how hard Quartz is to polish, it is mainly subsurface damage coming out I believe.
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