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Post by gmitch067 on Apr 26, 2019 20:49:53 GMT -5
I have a Hi-Tech Diamond 8 inch Flat Lap that can use smoothing disks made of a mesh like material with grit ratings of 220/325/600/1200/3000. www.therockshed.com/equipment16.htmlAfter happily using the system for a few months (worked about 50 cabs so far), I have a few questions… Q1: At what speed should these disks be used at? (I do not need to know the exact RPMs… just whether it should be FAST MEDIUM or SLOW... There are speeds that cause the unit to shake, and other speeds that produce a smooth feel. Max speed usually is smoothest… but is it the best speed for cabbing?) Q2: Do these smoothing disks need any maintenance to keep the mesh material from becoming pushed down into a compacted uneven mass? (My 325 grit disk has become so compacted that it has developed uneven areas that look hard and shiny… probably not good…) Q3: Can the diamond grit infused into the mesh material change locations or be lost with use or by using too much water? (At the end of a cabbing session I usually pour a couple cups of fresh water onto the center of the disk and turn the speed up to max for a few minutes. Would this cause any loss of grit???) |
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Post by hummingbirdstones on Apr 26, 2019 22:02:49 GMT -5
Glenn, you can use the discs at whatever speed you like. I tend to start slower on mine and then speed it up a bit if the material I'm cabbing is hard. I generally will speed it up to about 5 o'clock on the dial. Sometimes faster for really hard agate. My machine does not shake no matter the speed. It sounds like something may be off balance. Is your machine on a sturdy, flat surface?
The only maintenance I do to my discs is spin them at high speed for a few seconds to get the water off and then I leave them out to totally dry before I put them back in their plastic sleeve. You need to use the whole disc while you're cabbing so that the lap wears evenly. If you are just using the middle of the lap to cab, then the areas toward the center and toward the outside edge will be rougher and higher than the middle as you wear the diamond and resin away. Also remember you do not need to press overly hard on the lap. Pressing enough to keep the stone from chattering on the lap is hard enough. Let the diamond do the work.
On your last question - you can't wash the diamond off with too much water. It is impregnated in the resin, much like a Nova wheel. There really is no need to pour extra water on the lap after you're finished using it. If you're drip is keeping the lap wet while you cab, the centrifugal force is washing it off the edge continuously.
Hope that helps!
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Post by gmitch067 on Apr 27, 2019 1:29:58 GMT -5
Glenn, you can use the discs at whatever speed you like. I tend to start slower on mine and then speed it up a bit if the material I'm cabbing is hard. I generally will speed it up to about 5 o'clock on the dial. Sometimes faster for really hard agate. My machine does not shake no matter the speed. It sounds like something may be off balance. Is your machine on a sturdy, flat surface?
The only maintenance I do to my discs is spin them at high speed for a few seconds to get the water off and then I leave them out to totally dry before I put them back in their plastic sleeve. You need to use the whole disc while you're cabbing so that the lap wears evenly. If you are just using the middle of the lap to cab, then the areas toward the center and toward the outside edge will be rougher and higher than the middle as you wear the diamond and resin away. Also remember you do not need to press overly hard on the lap. Pressing enough to keep the stone from chattering on the lap is hard enough. Let the diamond do the work.
On your last question - you can't wash the diamond off with too much water. It is impregnated in the resin, much like a Nova wheel. There really is no need to pour extra water on the lap after you're finished using it. If you're drip is keeping the lap wet while you cab, the centrifugal force is washing it off the edge continuously.
Hope that helps!
Thank you Robin. I have the machine sitting on top of a small step stool/ladder. The rubber feet of the lap are spaced just right to straddle the stool's top step (going over both sides almost perfectly to hold it in place). There is no wobble , and the stool's feet spread out to give a nice stable platform. Considering your idea of it being off balanced... and your comment about the diamond grit being held in place with resin... I took a shop scissors and trimmed the outer edges of each smoothing disk to fit better on the composite main plate(s). Of all of the disks I mounted to main plates, each needed the trim job. The 325 grit disk was way out of true. The machine runs MUCH smoother at lower speeds now. Yaaa!!! The wear (compressed mesh) on my 325 grit disk progresses from a half inch out around the center hold-down screw/washer... all the way out to a quarter inch from the edge of the disk... which hides beneath the top lip of the splash guard. I try to use as much disk area as I can, and do so as evenly as I can. The areas that are compressed so much that they shine are scattered randomly all over the disk's surface. I am guilty of using too much pressure. I ordered a replacement 325 and 600 smoothing disks today. (Note: because I usually shift over to the Lot-O after cabbing at 600 grit, the finer smoothing disks have not been used as much... I have only used 1200 and 3000 grit when cabbing softer stones like Malachite and Chrysacolla.) |
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