jamesp
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Post by jamesp on Oct 2, 2014 4:54:01 GMT -5
Without my having to go back over 9 pages, did you ever answer why you went with the grinding weal laying flat instead of being vertical? Seems you would get more usable work area with the wheel vertical. But I haven't tried one yet, so that's just a guess. Definitely like my hand sitting on the table. Had one mounted vertical for years and was anxious to get it horizontal. For me, horizontal, no doubt.
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jamesp
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Member since October 2012
Posts: 36,169
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Post by jamesp on Oct 2, 2014 4:58:13 GMT -5
Doing some research. First time ever seen one with out the damn ribs. this one 30 and 40 grit diamonds. Perhaps wider ring.
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Post by captbob on Oct 2, 2014 4:59:16 GMT -5
Seems you could go vertical and still make a rest. Just make the rest a couple inches back from the wheel so there would be an open space for the cuttings to fly off into - downward. Sorry, I'm not gonna run out back and make an illustrative example at this hour. Maybe once it gets light! The ribs catch the stone a lot?
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,169
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Post by jamesp on Oct 2, 2014 5:06:17 GMT -5
For 3 inch sink drain hole. This one with a contour worn in the side wicked for tumbles, spheres. Perhaps safer. This bit does have 5/8-11 UNC for direct bolt on to arbor. Will have to shim table to raise hands to it.
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jamesp
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Member since October 2012
Posts: 36,169
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Post by jamesp on Oct 2, 2014 5:10:48 GMT -5
Seems you could go vertical and still make a rest. Just make the rest a couple inches back from the wheel so there would be an open space for the cuttings to fly off into - downward. Sorry, I'm not gonna run out back and make an illustrative example at this hour. Maybe once it gets light! The ribs catch the stone a lot? No. The debris goes to the right except occasionally. I run it w/out my shirt when its hot. Nothing like fragments when hammering rock. It is not as violent as you would think. The dust is the only thing that you need to protect yourself from aside from eye protection. Really pretty harmless.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,169
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Post by jamesp on Oct 2, 2014 5:20:26 GMT -5
This is new. Combo 5 inch cutter/grinder with wide diamond surface on top. But also diamonds on back. This might be the most versatile. 5/8-11 UNC. $29 Comes w/quad hole arrangement. I think that would adapt cutters used in the glass field. This looks like a big chunk one piece of sintered diamonds. Never seen anything like it. as the Chinese improve process large sintered pieces like this will become available at low price. Looks wicked. Wide diamond surface on top. Questioning the thickness of sintered diamonds. Cups are a whole 5mm.
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Post by captbob on Oct 2, 2014 5:29:26 GMT -5
Questioning the thickness of sintered diamonds.
Are the diamonds really even that relevant? I mean, it would seem like a grooved metal wheel spinning at a high speed is gonna do a number on a stone regardless of the diamonds.
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jamesp
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Member since October 2012
Posts: 36,169
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Post by jamesp on Oct 2, 2014 5:34:35 GMT -5
Questioning the thickness of sintered diamonds.Are the diamonds really even that relevant? I mean, it would seem like a grooved metal wheel spinning at a high speed is gonna do a number on a stone regardless of the diamonds. It is all about the diamonds. 100 grit diamond cup takes forever to remove material. 50 grit slow. But 30/40 grit will really remove fast. I have seen them w/16 grit diamonds on Aliexpress. no diamonds no cutting
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Post by captbob on Oct 2, 2014 5:38:26 GMT -5
Gotcha
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jamesp
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Member since October 2012
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Post by jamesp on Oct 2, 2014 5:45:32 GMT -5
Yea. if the diamonds are like 24 grit it eats a carp load of stone each revolution. But bigger than 30/40 grit like 16 and 24 will probably chip the heck out of the rock. I will experiment with the 50 grit for glass and obsidian. the 30/40 wants to send chips, worse on glass. But if the rock is way of round the chipping comes in handy to quick shape. Been tumbling the glass from the 30/40 wheel and never seen a single fracture going into the glass-never. It just surface chips it. That surprised me.
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jamesp
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Member since October 2012
Posts: 36,169
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Post by jamesp on Oct 2, 2014 5:54:12 GMT -5
I put a couple of those 3/4 pound obsidians and a blue glass in the tumbler yesterday at noon. Will pull them today at noon to check the progress. Learned something, do not sit the tumbler barrel down for long when running glass filler on obsidian and glass chunks with no sugar. It set up like concrete on the bottom. i added two cups of sugar to free up the jam. Not a problem during fine grits, but coarse grits make a lot of wet powder. The 7/8 full barrel does not overcome the concretion with out lubricant. I will not be surprised to see bruises with those big balls rolling together even with tumbler packed full. Rotary tumbling obsidian tricky, rotary tumbling big obsidian trickier. Testing the limits. I will be in trouble wit rockpickforever Jean. She sent me a bunch of chunks of obsidian that are mostly rock dust now. Obsidian not famous for coming in round chunks.
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jamesp
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Member since October 2012
Posts: 36,169
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Post by jamesp on Oct 2, 2014 6:08:00 GMT -5
I got buckets of Rio Grande agates. Looking forward to grinding the sun burnt coating off of them and tumbling. they are already oval/ball shaped. Just gotta skin the coating off, about an 1/8 of an inch. Say 40-60 seconds for a 2 inch pebble. Won't take long to get a barrel full. 2 weeks coarse grind. Move to 220.
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quartz
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breakin' rocks in the hot sun
Member since February 2010
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Post by quartz on Oct 2, 2014 11:14:07 GMT -5
"COARASE" granite {read the wheel}, Guess it's true, people are finishing school and still can't read or write. Heck of a bunch of experiment, have enjoyed following.
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Post by rockpickerforever on Oct 2, 2014 11:22:01 GMT -5
I will be in trouble wit rockpickforever Jean. She sent me a bunch of chunks of obsidian that are mostly rock dust now. Obsidian not famous for coming in round chunks. James, do whatever you have to do to make them Purdy! Not gonna rile me one bit. You can't hardly tumble them in the weird shapes they were in. They definitely needed some grinding to whip them into shape. And to be able to see what kind they are, so you can segregate them into like hardnesses for tumbling. Grinding equals smaller rock, and lots of rock dust. C'est la vie...
Some of that obsidian I just sent you I had never seen before, a real variety. While going through slabs the other day, I came across a bag of assorted small slabs I had picked up at a show last spring. Included was a small triangle-shaped slab of obsidian that had thin spiderweb-like blue lines running through it. Real pretty. That was a new one on me as well. Another show coming up there in a week, may have to go check it out just to find more of that.
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panamark
fully equipped rock polisher
Member since September 2012
Posts: 1,343
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Post by panamark on Oct 2, 2014 13:01:07 GMT -5
All this, and I am still stinging from Ann's ( fantastic5 ) "I trust my husband as completely as you can trust a man" Ouch!!! < I know exactly what you mean Ann. Just funnin' ya >
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jamesp
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Member since October 2012
Posts: 36,169
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Post by jamesp on Oct 2, 2014 14:07:16 GMT -5
That's funny Mark.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,169
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Post by jamesp on Oct 2, 2014 14:21:37 GMT -5
I will be in trouble wit rockpickforever Jean. She sent me a bunch of chunks of obsidian that are mostly rock dust now. Obsidian not famous for coming in round chunks. James, do whatever you have to do to make them Purdy! Not gonna rile me one bit. You can't hardly tumble them in the weird shapes they were in. They definitely needed some grinding to whip them into shape. And to be able to see what kind they are, so you can segregate them into like hardnesses for tumbling. Grinding equals smaller rock, and lots of rock dust. C'est la vie...
Some of that obsidian I just sent you I had never seen before, a real variety. While going through slabs the other day, I came across a bag of assorted small slabs I had picked up at a show last spring. Included was a small triangle-shaped slab of obsidian that had thin spiderweb-like blue lines running through it. Real pretty. That was a new one on me as well. Another show coming up there in a week, may have to go check it out just to find more of that.
They will just look like black rocks if they don't see a little trimming down and elbow grease Jean. I don't think any 2 were the same type. I will be tickled if they all shine up in one batch. About half have been processed. One of them was a black chert, hard enough to skin the diamonds off of the trim saw blade. Fine selection, I will do my best w/them. Obsidian is a strange bird. Cuts like butter on the tile saw. One of them was a pebble of snowflake shaped just like a goose egg.one was brecciated and rehealed. Another was dog turd colored. Having fun w/them and thanks.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,169
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Post by jamesp on Oct 2, 2014 14:24:05 GMT -5
"COARASE" granite {read the wheel}, Guess it's true, people are finishing school and still can't read or write. Heck of a bunch of experiment, have enjoyed following. about all them wheels came from across the pond. Great sintered diamonds, bad english.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,169
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Post by jamesp on Oct 3, 2014 11:54:26 GMT -5
Stepped up the speed by changing cups from a 4.5 inch to a 7 inch. 7 inch cup has a flat face. Speed at diamonds picked up from 3040 to 4740 ft/min with diameter change. Man did that thing come alive. Picked a couple of deceptive Rio pebbles to facet a couple of octomodecahedral crystals. these will coarse tumble fast: After two days in the tumbler the 3/4 pounders are starting to round. White spots not bruises from tumbling but from aggressive diamond wheel. They will tumble away. Hopefully no bruises. A crazy assortment of obsidians from Birthday Jean that she had been stashing for many many years. Most pre-ground, three days in tumbler.All in 30/60 SiC grit.
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Post by rockpickerforever on Oct 3, 2014 12:03:08 GMT -5
A crazy assortment of obsidians from Birthday Jean that she had been stashing for many many years. Most pre-ground, three days in tumbler.All in 30/60 SiC grit. Wow, James, lookin' good! They definitely are an assortment, but, to set the record straight... Most of them I picked up at the free rock sale last month, so have not had them for many, many years. But a few of them (bigger chunks of snowflake, mainly) were picked up at an estate sale a couple years ago.
They did need preshaping on the King Kong grinder, to make them nice and rounded, so they are not some strange wonky shapes, and polish better.
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