Fossilman
Cave Dweller
Member since January 2009
Posts: 20,687
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Post by Fossilman on Jun 30, 2016 9:43:52 GMT -5
Holy Holly "Batman" your bat cave has some beautiful displays of Coral!!! Two thumbs up James! Liking the architect of the room too!
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Post by tims on Jun 30, 2016 15:56:49 GMT -5
Thanks again James. I'll get the 200-3000 in the same 5" as i'm afraid 4" would be a little cramped to work with. I'm not sure exactly how to do the AO stage, would just a wet piece of leather laid over glass work ok?
I've been haunting ebay looking for a cheap 6" lap but it seems the days of smoking deals on ebay are a thing of the past. That's fine though; Summer is slow for my PC business and I've got more time than money. Plus the process is very meditative.
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jamesp
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Member since October 2012
Posts: 36,178
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Post by jamesp on Jul 2, 2016 7:23:48 GMT -5
Holy Holly "Batman" your bat cave has some beautiful displays of Coral!!! Two thumbs up James! Liking the architect of the room too! Thanks Michael. Come see me sometime.
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Post by tims on Jul 5, 2016 20:37:41 GMT -5
Polished (?) vs Cut
Got the rest of my pads today and spent the afternoon working through them at 20-30 min. per stage, finishing with aluminum oxide polish on wet leather. I swear it looked shinier after the 3000 pad and before polish but maybe my eyes just got accustomed to the smoother finish. This was a test run so i'm not sure I spent enough time on it for a proper polish ... I figure about 120-180 rpm so 10 or 15 minutes my time per 1 on a lap @ 1800 rpm. I'm also assuming you'd get better downward pressure using a lap which might make it even quicker especially at the rough stages.
I'd like to borrow a good saw and try to get a good thin slab to work on --- i'm guessing the translucence would brighten it up a bit vs. this heel piece. There are some noticeable hairline fractures though that I hadn't noticed before. They seem healed (I can't feel them) but i'm wondering if cutting a thin piece might prove me wrong and break.
Anyway, comments and suggestions welcome.
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Post by Garage Rocker on Jul 5, 2016 20:57:12 GMT -5
OK, that's some cool rock you got there. Whatever you're trying, I like it. Keep up the experimenting and sharing results.
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jamesp
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Member since October 2012
Posts: 36,178
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Post by jamesp on Jul 5, 2016 23:16:09 GMT -5
You can speed up the operation vastly by tackling a small rock. A 1.5 inch pebble sawn in half. Or small piece of a slab. My 3600 rpm pads slap a 6 stage to polish on small faces very quickly. 6 stages on a 5 X 5 inch surface takes way longer.
Or you can try a piece of fluorite and speed the 6 to 8 step process X 10's. Go for soft stone. They don't tumble polish well but they will take a fine polish on those pads. 50 pads chops thru fluorite like sandpaper on wood.
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Post by tims on Jul 6, 2016 21:40:26 GMT -5
OK, that's some cool rock you got there. Whatever you're trying, I like it. Keep up the experimenting and sharing results. I'm really not sure what i'm doing Just trying to put a little shine on some rough cuts for now I guess.
jamesp I took your advice and cut a few little teepee nodules today and spent about 45min total going from 50-3000 on one piece. Waaaay faster than the big slab, especially since it's easier to cut small stuff without getting blade gouges.
This piece is 2" x 1 3/4" and it looks better than the rushed photo ... i'm going to wait on the AlO stage until I've got a few pieces ready just to save on cleanup. I'm also going to grab a 8,000 pad, and wish they had something still finer because i'm loving the pads. This piece is still nearly 2" deep but I keep breaking the teepee stuff when I try to cut slabs < 1" thick (the heel piece on this fell apart) so i'm just keeping it as is for now.
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jamesp
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Member since October 2012
Posts: 36,178
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Post by jamesp on Jul 7, 2016 21:03:01 GMT -5
I used to adjust the 18 inch saw with a micrometer pointer. Cut at slowest speed. About lost all saw marrks. That is the trick for lapping big stuff. Little stuff, well you found out how fast it is. The auto feed cuts 2 inch and less with best sawn finish, 400 800 1500 and game on. Pretty sure they make a 10,000 pad and a polish pad whatever that might be.
Hard to beat that diamond impregnated rubber for cutting fast.
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Thunder69
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Thunder 2000-2015
Member since January 2009
Posts: 3,102
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Post by Thunder69 on Jul 8, 2016 20:30:16 GMT -5
The pictures don't do the displays justice.....When you see it in person the wow factor triples...John
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huskeric
spending too much on rocks
Member since May 2016
Posts: 353
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Post by huskeric on Jul 11, 2016 16:23:13 GMT -5
Not to threadjack, but would those diamond pads work on a random orbit polisher? I have one for my car, and it's got variable speeds, but I don't know if it would give you ample control or the work piece without ripping it out of your hand. I was thinking it could be clamped into a workmate or something to hold it, and you could work the stone by hand. It could potentially be really nice because it would minimize any markings on the stone. Thoughts?
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Post by tims on Jul 15, 2016 6:32:09 GMT -5
Not to threadjack, but would those diamond pads work on a random orbit polisher? I have one for my car, and it's got variable speeds, but I don't know if it would give you ample control or the work piece without ripping it out of your hand. I was thinking it could be clamped into a workmate or something to hold it, and you could work the stone by hand. It could potentially be really nice because it would minimize any markings on the stone. Thoughts? The biggest concern would probably be RPM. If you could slow it down to what, 1200 rpm or so? i'd think it would work ok. Even faster might work fine. Of course you'd need to keep the stone wet somehow. Maybe jamesp could give you a definitive answer; I think he's using these on a grinder but i'm not sure of what speed, if it's a wet grinder, or how he clamps / mounts the grinder or stone. I found a 5" hard backing plate and a shank to use it in an electric drill but haven't tried it on anything yet. I'm thinking the drill will be too low RPM but i'm still tempted to try it for the 50 stage just to save on elbow grease. Honestly once you get past that first stage, the rest is a piece of cake by comparison. If you do try the orbital polisher please share your results.
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jamesp
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Member since October 2012
Posts: 36,178
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Post by jamesp on Jul 15, 2016 6:59:13 GMT -5
1) Keep RPM below 3600 or else heat build up will melt rubber holding diamonds 2) Any speed from say 500 to 3600 RPM helps speed process. 1200 RPM sounds like a sweet speed. Slower means less vibration, vibration leaves marks. A perfectly aligned 3600 RPM backing plate is perfectly fine though. It does however sling cooling/lubricating water off much faster. If redesigning, I would go with 800-1200 RPM to reduce water sling-off. El cheapo Walmart 5 inch grinders are 3600 RPM, so the high speed on my machine. 3) The only clamp I ever used was my fingers. So the face of stone can be randomly passed over the moving face so as not to burn a pattern into the rock face.
Yes, once the face is flattened, 100-200-400-800-1500-3000 a breeze.
The biggest problem I had was grinding the Velcro backing off the back of the pads and glueing them to the face plate. Even if the face plate is turning dead true the glue process left slight humps in the pad even though I clamped the crap out of them when epoxied. Best if those pads could be ordered without the velcro backing when being glued to a higher speed face plate. I wish they made those pads 12 or 16 inches in diameter and turn them say 300 RPM. I assume they will one day. It would be the super fast cutting ultimate lap.
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jamesp
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Member since October 2012
Posts: 36,178
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Post by jamesp on Jul 15, 2016 7:09:21 GMT -5
Maybe better using the velcro face plate. At 3600 RPM they have a habit of moving to out-of-center. No thanks. I glued mine. But at 800-1200 RPM centrifugal forces would be much less a problem for the factory made velcro face plates. Then you could simply have one velcro face plate driven and switch pads easily as they were designed to be used. Gotta feed water......so the ole lap bowl design would keep you dry. 1200 RPM fast for a lap...
these issues coming back to me from original testing
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huskeric
spending too much on rocks
Member since May 2016
Posts: 353
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Post by huskeric on Jul 15, 2016 10:54:01 GMT -5
tims, thanks for the thoughts. I have the Porter Cable 7424XP, and the slowest I can dial it down is 2,500RPM, so that may not be a workable solution. On top of that per jamesp's comments on vibration, trying to clamp that sucker into a base that wouldn't shake like mad would be..... difficult. If I had a piece of rock that was large enough, I could clamp THAT and work the polisher by hand. I have an angle grinder, but that sucker runs at 11K RPM, so I think that's a non-starter. I had thought about getting a velcro pad and some of the diamond pads for that, so I'm REALLY glad you guys are so helpful, else I would have created a colossol fail for myself. (sigh) Well, maybe I just need to stick to tumbling for now until a) I get more experience/knowledge under my belt and b) I am ready to invest the time/money into building/buying the right tool for the job.
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jamesp
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Member since October 2012
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Post by jamesp on Jul 26, 2016 4:53:13 GMT -5
timsWhat would those 50 grit fast cutting pads do if cut up and run as tumbler media ? They should last a long time unless they wore against each other. They would have to last a long time to be economically feasible. Or get the overseas guys to make a rotary barrel like a sold rubber Lortone 12# out of 50 grit diamond for rough shaping.
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Post by tims on Jul 26, 2016 10:48:46 GMT -5
Hmmm interesting ideas. It would be an expensive experiment to dice them up for media, but who knows once you had a barrel's worth you might never need grit again. The lined barrel idea would be nice and simple but i don't know how effective it would be without the rocks being able to mix with the tumbling media on all sides. Again though, who knows ... if it did work it might last a good long time.
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jamesp
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Member since October 2012
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Post by jamesp on Jul 26, 2016 12:19:23 GMT -5
Hmmm interesting ideas. It would be an expensive experiment to dice them up for media, but who knows once you had a barrel's worth you might never need grit again. The lined barrel idea would be nice and simple but i don't know how effective it would be without the rocks being able to mix with the tumbling media on all sides. Again though, who knows ... if it did work it might last a good long time. Was thinking about a slanted bowl that created shear instead of a rolling tumble. With a standing wave of rocks on a slant. Only because of the extreme cutting rate of those pads. diamond crystals are fairly round and do not cut so well unless a lot of down force is applied. those pads have crushed diamonds and are very sharp yet long lasting. Might be the fastest cutting media and longest lasting of all cutting medias for Mohs 7 rocks known. I wish they sold it in sheets, like 12 inches wide and however long you want.
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Deleted
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Post by Deleted on Jul 26, 2016 12:32:17 GMT -5
timsWhat would those 50 grit fast cutting pads do if cut up and run as tumbler media ? They should last a long time unless they wore against each other. They would have to last a long time to be economically feasible. Or get the overseas guys to make a rotary barrel like a sold rubber Lortone 12# out of 50 grit diamond for rough shaping. Not a barrel, but a barrel liner like you recently made of vinyl
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Post by tims on Jul 26, 2016 14:54:47 GMT -5
I assume those are originally manufactured in sheets, if you could find a way to contact the original manufacturer.
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Deleted
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Post by Deleted on Jul 26, 2016 15:22:33 GMT -5
I assume those are originally manufactured in sheets, if you could find a way to contact the original manufacturer. If they are made in sheets they are sheets of circles. That would leave a big space with no pad between the circles. Need sheets made to barrel with and circumference. Cutting would destroy any cutter used pretty quickly. Might be doable as a home project with caulking material and diamond grit. I sincerely doubt the efficacy. Stones cut each other in the barrel as they are covered in grit. Grit in a barrel liner will stop them from sliding, but there will be little if any cutting action.
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