jamesp
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Post by jamesp on Jul 27, 2020 4:29:23 GMT -5
Sintered diamond blade beads range in size from 8mm to 11mm. What would 20% of this media do to rocks in step 1 ? How long would they last wearing against each other in the rotary ? Probably 3 to 4 times denser than rock so barrel weight would increase dramatically. Heavy grinds harder.
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wpotterw
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Post by wpotterw on Jul 27, 2020 8:54:28 GMT -5
Sintered diamond blade beads range in size from 8mm to 11mm. What would 20% of this media do to rocks in step 1 ? How long would they last wearing against each other in the rotary ? Probably 3 to 4 times denser than rock so barrel weight would increase dramatically. Heavy grinds harder. Back in my quarry permitting/design days, I had a client with a diabase quarry in/near the Reading Prong. They made building cornerstones and cemetary monuments. The cable blades in your pics look very much like the blade on their 26 foot band saw used to cut massive blocks apart. They smaller portable band saws to cut blocks in the quarry and a 10' diamond circular saw that swung like a pendulum across the piece and cut 1/16" to 1/32" per cut. All day to make one cut. I would only use those beads on something that is hard, dense and oversized. I think it would grind smaller pieces into dust.
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Post by HankRocks on Jul 27, 2020 9:18:13 GMT -5
Sintered diamond blade beads range in size from 8mm to 11mm. What would 20% of this media do to rocks in step 1 ? How long would they last wearing against each other in the rotary ? Probably 3 to 4 times denser than rock so barrel weight would increase dramatically. Heavy grinds harder. Back in my quarry permitting/design days, I had a client with a diabase quarry in/near the Reading Prong. They made building cornerstones and cemetary monuments. The cable blades in your pics look very much like the blade on their 26 foot band saw used to cut massive blocks apart. They smaller portable band saws to cut blocks in the quarry and a 10' diamond circular saw that swung like a pendulum across the piece and cut 1/16" to 1/32" per cut. All day to make one cut. I would only use those beads on something that is hard, dense and oversized. I think it would grind smaller pieces into dust. Most Agate is pretty hard, and your words "grind smaller pieces into dust" got my attention. If it is indeed true then those beads would represent the "Holy Grail" of rock tumbling. Some way to reduce rough, pitted rocks into smooth stones ready for the next stages. If they do cut fast, then one just has to monitor the progress closely. As it stands now, to smooth some pieces without pre-grinding them, may take months in the Tumbler. If that could be reduced to a week or so, then no rock in my garage or yard would be safe!!!
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EricD
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Post by EricD on Jul 27, 2020 9:42:41 GMT -5
And this brings up the question "Why not just use diamonds for grit?"...
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pizzano
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Post by pizzano on Jul 27, 2020 10:11:47 GMT -5
I believe I saw something like that being used at a construction site back in the day. We were slope staking and setting up slope benches at every 300' vertical along the a mountain side near the Cleveland National Forest and City of Corona, CA boundary. Once the slope was rough cut, in areas where cuts were made in solid Granite, they had two very large long arm excavators, something along the line of a Cat 320E.
Attached to the end of the reach on each machine was a pneumatic powered set of large tires (wheels) that were wrapped in radial chains (much like a snow tire radial chain), that was used to grind sections of slope that could not be easily accessed by horizontal cutting rakes. They had boxes and and boxes of these chains laid out on the slope benches where each excavator was working (grinding below where it was stationed)...........
Those chains worked very fast and seemed to last a little over an hour of continuous use before they were swapped out by a crew that had the exercise down pat. The used chains were stocked piled to be recycled. From what I understand, the cutting bits (beads) were made of some kind of diamond material and were not cheap. They (the chains) could be re-used only couple of times, the manufacture would recondition them.
I don't have any idea if this process is still being used........but it seemed to be efficient at the time, for specific types of rock slope grinding....!
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jamesp
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Post by jamesp on Jul 27, 2020 10:17:56 GMT -5
There are several types of abrasive diamonds. Some are smooth whole crystals, others are larger crystals broken into very sharp pieces. So something to keep in mind is that sharp broken crystals cut much faster than whole smooth crystals. Especially in a rotary tumbler where the grinding pressures are much lower than say a hydraulic diamond drill or a tightly stretched diamond rope. Sintered diamonds are top of the line since they are fused throughout the matrix, where electroplated wheels and bits are only surface coated. And sintered crushed diamonds are really top of the line for low pressure grinding and tumbling. You could use loose diamonds EricD but you would have to scavenge them with clean water wash downs each use which may not be an issue. Other than that the initial cost. Anyway, it takes forever to grind/shape agates. I would certainly not complain about faster cutting abrasives in step 1.
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EricD
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Post by EricD on Jul 27, 2020 11:22:59 GMT -5
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jamesp
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Post by jamesp on Jul 27, 2020 16:03:11 GMT -5
The darn rocks knocked every diamond particle exposed out of those rubber pads. Probably due to flexing in the rotary. The rubber discs lost all the diamonds at the surface. So the rubber matrix did not hold the diamond particles tight in the rotary. This was a shame because the 30 grit diamonds impregnated/melted into the rubber were extremely sharp. If you drug that disc across your knuckles it removed skin quick, bleeding was next step. I sure would like to have a measuring cup full of crushed diamonds sifted to 10 to 20 grit size that could be recaptured easily. They would have to be crushed from very large and expensive synthetic diamond crystals to be 10 to 20 grit in size. I mention the sintered beads because of their pea gravel size and they probably contain only 10% diamonds and 90% sintering metals instead of being 75% to 100% by volume diamonds and therefore being expensive. Pretty sure the sintering would hold on to the diamonds unlike the rubber pads.
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EricD
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Post by EricD on Jul 27, 2020 22:12:39 GMT -5
If you wish to use diamonds to abrade rock perhaps you need to purchase some crushed diamonds. Seems economical to me. Perhaps I will give it a shot. Very likely I will give it a shot. I'm tired of SiC
You don't need something to hold the diamonds. They are their own time release abrasive.
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jamesp
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Post by jamesp on Jul 28, 2020 5:34:11 GMT -5
If you wish to use diamonds to abrade rock perhaps you need to purchase some crushed diamonds. Seems economical to me. Perhaps I will give it a shot. Very likely I will give it a shot. I'm tired of SiC You don't need something to hold the diamonds. They are their own time release abrasive. I wish I could find a bucket of synthetic diamonds. Not trying to crap on the idea but... 50 grit diamonds cost about $10/5 grams on EBAY. density is 3.2 grams per milliliter 1 measuring cup is 236 milliliters [236 x 3.2 x 10]/5 = $1500/cup. Lest my calculations or costing is off(very possible) I picked a cup because that is the amount of SiC I use(or more) for 12 pounds of rock for thorough distribution. 1 cup raw SiC costs 20 cents based on paying $45/50 pound bag, 240 cups/bag. Recapturing 50 grit diamond particles at 3.2 density might be a challenge just saying. You have to separate them to reuse them so the suggestion of the sintered bead 'media' making recapture easy. Thoughts ? Crap SiC works near as well as graded/sifted SiC for step 1 in rotary. The less pure form of SiC is real cheap but highly effective for step 1 in rotary. It is not my favorite abrasive either but it might be the most bang for buck. It is messy but so is the mud and slurry generated. SiC wears and times out. Gets tossed with the slurry. Well enough.
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Post by HankRocks on Jul 28, 2020 6:21:04 GMT -5
If you wish to use diamonds to abrade rock perhaps you need to purchase some crushed diamonds. Seems economical to me. Perhaps I will give it a shot. Very likely I will give it a shot. I'm tired of SiC You don't need something to hold the diamonds. They are their own time release abrasive. I wish I could find a bucket of synthetic diamonds. Not trying to crap on the idea but... 50 grit diamonds cost about $10/5 grams on EBAY. density is 3.2 grams per milliliter 1 measuring cup is 236 milliliters [236 x 3.2 x 10]/5 = $1500/cup. Lest my calculations or costing is off(very possible) I picked a cup because that is the amount of SiC I use(or more) for 12 pounds of rock for thorough distribution. 1 cup raw SiC costs 20 cents based on paying $45/50 pound bag, 240 cups/bag. Recapturing 50 grit diamond particles at 3.2 density might be a challenge just saying. You have to separate them to reuse them so the suggestion of the sintered bead 'media' making recapture easy. Thoughts ? Crap SiC works near as well as graded/sifted SiC for step 1 in rotary. The less pure form of SiC is real cheap but highly effective for step 1 in rotary. It is not my favorite abrasive either but it might be the most bang for buck. It is messy but so is the mud and slurry generated. SiC wears and times out. Gets tossed with the slurry. Well enough. It would be a lot easier to re-capture the Beads and as you say it's a lot more cost effective than the loose diamonds. May just go ahead and buy a 1000 of them and see how they work. Just wish I didn't have deal with China.
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EricD
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Post by EricD on Jul 28, 2020 7:13:19 GMT -5
If you wish to use diamonds to abrade rock perhaps you need to purchase some crushed diamonds. Seems economical to me. Perhaps I will give it a shot. Very likely I will give it a shot. I'm tired of SiC You don't need something to hold the diamonds. They are their own time release abrasive. I wish I could find a bucket of synthetic diamonds. Not trying to crap on the idea but... 50 grit diamonds cost about $10/5 grams on EBAY. density is 3.2 grams per milliliter 1 measuring cup is 236 milliliters [236 x 3.2 x 10]/5 = $1500/cup. Lest my calculations or costing is off(very possible) I picked a cup because that is the amount of SiC I use(or more) for 12 pounds of rock for thorough distribution. 1 cup raw SiC costs 20 cents based on paying $45/50 pound bag, 240 cups/bag. Recapturing 50 grit diamond particles at 3.2 density might be a challenge just saying. You have to separate them to reuse them so the suggestion of the sintered bead 'media' making recapture easy. Thoughts ? Crap SiC works near as well as graded/sifted SiC for step 1 in rotary. The less pure form of SiC is real cheap but highly effective for step 1 in rotary. It is not my favorite abrasive either but it might be the most bang for buck. It is messy but so is the mud and slurry generated. SiC wears and times out. Gets tossed with the slurry. Well enough. The thing I don't like about the beads the most is that you're replacing your SiC with metal, basically, that has a few diamonds in it. I think, for the same effect, you would need more dollar amount for beads than for raw diamond.
Think about the grit you are using now, how many little scratching "fingers" it has. Now compare that to how many you would have with beads. One very well may have to replace most of their rocks with beads to make it effective.
Edit: $336 would buy you a cup of the 50 grit diamond I linked in a post above. 100 grams is 1.33T x 12 = almost exactly a cup or 16T
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jamesp
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Post by jamesp on Jul 28, 2020 8:02:42 GMT -5
$336 is a much better number. Nice find. I was looking at small 5 gram packages, probably the most costly. I bought a 4"x4"x3" box packed full of sintered quarry saw blade replacement teeth for about $50. Each piece was 3/8x3/8x3/4. But they had round synthetic diamond crystals in them and were totally useless in the rotary's low grinding pressure situation. I have no idea if the diamond beads have round crystals or sharply cracked diamonds. My guess is that they are cheap anyway. The electroplated beads are loaded with diamonds. Their life may be questionable. They have serious job to do though. These electroplated ones look darn aggressive to me: Another problem with tumbling some metals is gas production. These look cracked and sharp:
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jamesp
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Post by jamesp on Jul 28, 2020 8:23:45 GMT -5
I wish I could find a bucket of synthetic diamonds. Not trying to crap on the idea but... 50 grit diamonds cost about $10/5 grams on EBAY. density is 3.2 grams per milliliter 1 measuring cup is 236 milliliters [236 x 3.2 x 10]/5 = $1500/cup. Lest my calculations or costing is off(very possible) I picked a cup because that is the amount of SiC I use(or more) for 12 pounds of rock for thorough distribution. 1 cup raw SiC costs 20 cents based on paying $45/50 pound bag, 240 cups/bag. Recapturing 50 grit diamond particles at 3.2 density might be a challenge just saying. You have to separate them to reuse them so the suggestion of the sintered bead 'media' making recapture easy. Thoughts ? Crap SiC works near as well as graded/sifted SiC for step 1 in rotary. The less pure form of SiC is real cheap but highly effective for step 1 in rotary. It is not my favorite abrasive either but it might be the most bang for buck. It is messy but so is the mud and slurry generated. SiC wears and times out. Gets tossed with the slurry. Well enough. It would be a lot easier to re-capture the Beads and as you say it's a lot more cost effective than the loose diamonds. May just go ahead and buy a 1000 of them and see how they work. Just wish I didn't have deal with China. They range in size from 8mm to 11mm diameter cylinders. About the same in length. They are really heavy(bronze and cobalt alloy). If they were solid they would be much heavier. Anyway, a nice media size. Being an expendable they should be affordable. The steel cable rope uses 30 to 40 beads per meter. They don't do well cutting carbon steel in air due to heat damage. They are used underwater for cutting sunken ships up for salvage since the water keeps them cool. No heat issues with a rotary.
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EricD
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Post by EricD on Jul 28, 2020 8:27:18 GMT -5
Those do look like they could do some damage. Also agree they would be easier to recover. The space they take up is really the only reason I wouldn't use them, depending on how many were needed. Who knows, maybe only one would be enough to do the job of a cup of SiC?
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jamesp
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Post by jamesp on Jul 28, 2020 19:11:59 GMT -5
Those do look like they could do some damage. Also agree they would be easier to recover. The space they take up is really the only reason I wouldn't use them, depending on how many were needed. Who knows, maybe only one would be enough to do the job of a cup of SiC? If I see a place to purchase I may go ahead regardless of the space loss. If a these served as a replacement for coarse SiC in shaping it would be a big victory. Lortone instructions suggest 1 cup of coarse grit for 12 pounds or 1.3 gallons of rocks. No idea who came up with the doses we use in tumbling. A gallon is about 15 cups. Maybe a cup full of beads would be a good starting point. Like slurry, abrasives only fill void volume and of course media takes valuable space. The sharpest diamonds I have found in a sintered grinding wheel was in this $25 7 inch 1/4 inch thick tuck wheel. And they have stayed sharp after grinding 100's of agates mounted in a 4000 rpm tile saw. Because I know they are super sharp 30 grit sinterings I would consider cutting the sintered sections off to serve as media. The results of rubbing a hard fossil coral against this Advanta tuck blade with light pressure. Deep gouges:
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jamesp
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Post by jamesp on Jul 28, 2020 19:26:42 GMT -5
I believe I saw something like that being used at a construction site back in the day. We were slope staking and setting up slope benches at every 300' vertical along the a mountain side near the Cleveland National Forest and City of Corona, CA boundary. Once the slope was rough cut, in areas where cuts were made in solid Granite, they had two very large long arm excavators, something along the line of a Cat 320E.
Attached to the end of the reach on each machine was a pneumatic powered set of large tires (wheels) that were wrapped in radial chains (much like a snow tire radial chain), that was used to grind sections of slope that could not be easily accessed by horizontal cutting rakes. They had boxes and and boxes of these chains laid out on the slope benches where each excavator was working (grinding below where it was stationed)........... Those chains worked very fast and seemed to last a little over an hour of continuous use before they were swapped out by a crew that had the exercise down pat. The used chains were stocked piled to be recycled. From what I understand, the cutting bits (beads) were made of some kind of diamond material and were not cheap. They (the chains) could be re-used only couple of times, the manufacture would recondition them.
I don't have any idea if this process is still being used........but it seemed to be efficient at the time, for specific types of rock slope grinding....!
Quarries use these pizzano. They can even cut kitchen countertop granite with them. Apparently they are predictable and accurate. An efficient way to go. I think they water jet a hole in a bluff of granite, thread the cable thru, hook it to the pulleys and cut away. In Georgia a common size quarry block is 5' X 5' X 10'. Perhaps for countertop slabs.
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EricD
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Post by EricD on Jul 28, 2020 19:33:24 GMT -5
Those do look like they could do some damage. Also agree they would be easier to recover. The space they take up is really the only reason I wouldn't use them, depending on how many were needed. Who knows, maybe only one would be enough to do the job of a cup of SiC? If I see a place to purchase I may go ahead regardless of the space loss. If a these served as a replacement for coarse SiC in shaping it would be a big victory. Lortone instructions suggest 1 cup of coarse grit for 12 pounds or 1.3 gallons of rocks. No idea who came up with the doses we use in tumbling. A gallon is about 15 cups. Maybe a cup full of beads would be a good starting point. Like slurry, abrasives only fill void volume and of course media takes valuable space. The sharpest diamonds I have found in a sintered grinding wheel was in this $25 7 inch 1/4 inch thick tuck wheel. And they have stayed sharp after grinding 100's of agates mounted in a 4000 rpm tile saw. Because I know they are super sharp 30 grit sinterings I would consider cutting the sintered sections off to serve as media. The results of rubbing a hard fossil coral against this Advanta tuck blade with light pressure. Deep gouges: I was thinking of doing the same thing instead of the beads and loose diamonds. Haha. You have less metal per diamond and pretty brutal reduction going that route. Appreciate the abrasion photo. I think just a few sections of that blade would have surprising effect in little time on rounding the subjects.
As a side note the diamonds I linked were polycrystalline which means they have more cutting edges than monocrystalline ones. I'm sure you know that but thought I would mention it.
Cheers. Good discussion!
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jamesp
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Post by jamesp on Jul 28, 2020 21:08:31 GMT -5
It's a great discussion EricD. I don't think many people try to think too far out of the box when it comes to improving the tumbling process. The process is mesmerizing to me. Tumble finishing on a large scale would likely make a fine business.
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EricD
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Post by EricD on Jul 28, 2020 21:29:47 GMT -5
It's a great discussion EricD . I don't think many people try to think too far out of the box when it comes to improving the tumbling process. The process is mesmerizing to me. Tumble finishing on a large scale would likely make a fine business. I have seen quite a few people on this forum refuse to think outside the box since I have been here, and I usually just bow my head and walk away from the discussion rather than raise dust, or their tail feathers.
Unfortunately I may have driven entropy off with a simple statement about perfection. He would have contributed a lot here if I had not, perhaps. Ah well.
Tumbling is by far my first attraction to the stones and processes, I would not even be here on RTH without it.
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