chadman
starting to spend too much on rocks
Member since March 2008
Posts: 106
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Post by chadman on May 26, 2008 23:10:07 GMT -5
The foundation for my next project
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drjo
fully equipped rock polisher
Honduran Opal & DIY Nut
Member since May 2008
Posts: 1,581
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Post by drjo on May 27, 2008 11:48:14 GMT -5
And it is a .....? How about a side pic? Purty PLEASE!
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cutter
starting to spend too much on rocks
Member since February 2008
Posts: 129
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Post by cutter on May 27, 2008 18:50:36 GMT -5
About 18 inches?
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Rockygibraltar
fully equipped rock polisher
Member since February 2006
Posts: 1,404
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Post by Rockygibraltar on May 27, 2008 22:48:02 GMT -5
That will make a good lapping wheel.
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adrian65
Cave Dweller
Arch to golden memories and to great friends.
Member since February 2007
Posts: 10,777
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Post by adrian65 on May 27, 2008 23:29:38 GMT -5
Interesting, I can't wait for new pics. What material is that disk made from?
Adrian
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chadman
starting to spend too much on rocks
Member since March 2008
Posts: 106
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Post by chadman on May 28, 2008 14:03:36 GMT -5
Interesting, I can't wait for new pics. What material is that disk made from? Adrian It is cast iron. I'll show more picks and document construction later this summer. I have a vibrating lap so I'm thinking of using this for finish lap. You can make lap plates out of mild steel. They don't have to be perfectly machined flat because the the nature of the lapping process. I used to work for a huge production machine shop as a young man. I was a maintenance oiler. They had 3 - 6' rotating laps machines. The engineers told me that flat laps could achieve within 1/11,000,000,000 inch flatness. To determine flatness they used a light band optical table. If you look at your reflection in the surface of a CD disc and gently bend the disc you see your reflection distort. Light band tables use the same principle to detect flatness of parts. If the light bands from the refection of the surface of the part are bent, then it's not flat. Quite amazing to see. You can take a carbon and a stainless steel face lapped flat, breath on them for a little moisture and stick them together and the are almost impossible to pull directly apart from each other even by the strongest of persons. I have to work out the rotation speed (I'll need some help there). I want to make the motor drive the lap plate, a slurry bath agitator to keep the slurry mixed, and a peristaltic pump to pump the slurry onto the lap plate. I want to make all these from scratch. The lap plate, agitator and pump will move relatively slow. Watch out! Crazy man with a welder! ;D
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chadman
starting to spend too much on rocks
Member since March 2008
Posts: 106
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Post by chadman on May 28, 2008 14:09:37 GMT -5
And it is a .....? How about a side pic? Purty PLEASE! I'll get some pics tonight if I get a chance. You can have a local welding shop cut a round disc of any size to make your own lap. They don't need the grooves to work. Mild steel works fine.
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chadman
starting to spend too much on rocks
Member since March 2008
Posts: 106
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Post by chadman on May 31, 2008 3:32:38 GMT -5
Pic of the back side of the lap plate.
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Post by Woodyrock on Jun 4, 2008 15:20:29 GMT -5
Here are a couple of shots of my flat lap. This is not homemade, but pretty close. It was made by a small engineering company in Bremerton, Washington quite a few years ago. The engineer that made these machines used an automobile differential for both right angle drive, and gearbox. This should give you some good ideas to build your own. The lap plate is twenty inches to give some perspective as to size. Weight is another matter, it ain't light! Woody
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Post by parfive on Jun 4, 2008 15:38:40 GMT -5
That's a helluva machine, Woody! If you buy two, does it come with posi-traction?
Got any pics of what you've shined up on it?
Rich
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Post by Woodyrock on Jun 4, 2008 16:45:17 GMT -5
We did buy two, sort of anyhow. These were made as either a lap, or a polisher. I bought the lap, and my buddy bought the polisher from a lapidary that has become too old to pursue the craft.. My buddy already has one of the laps. The polisher's plate is 36 inches in diameter. I just recently bought this monster lap, so have not yet polished anything on it. I have however used my buddy's machine, which was the reason to jump on this one when it became available. It will soon have wheels because, I cannot move it alone. You should just see the magnificant saws this old engineer made. they make Highland Park saws look like toys! Woody
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