onewomanarmy
has rocks in the head
Carpe Silicis!
Member since January 2007
Posts: 645
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Post by onewomanarmy on May 21, 2009 15:29:38 GMT -5
The cutting board idea was great Nate! I tried this myself (though still trying to get that sucker as close to round as I can get it) and it seems to work nicely. I bought an Ameritool grinder a while back but have found I'd like one more plate than it came with. Didn't have enough extra money to invest in the real thing so thought I'd try this. Had the same trouble you did as far as the stuff melting as you cut. We paused to adjust our set up after we got started cutting and the cut "self healed" and locked our jig saw into the cutting board! Wonder if a little oil would cut that friction down at all? Probably just end up slinging it everywhere and still melting the plastic... Once we got going again, we managed to get a fairly roundish, though rough, disc out. I think I've about got it true enough that it's functional for what I want. Thanks for the idea - believe I owe you a cold beer (or Coke)!
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carloscinco
fully equipped rock polisher
Member since July 2008
Posts: 1,639
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Post by carloscinco on May 29, 2009 9:00:11 GMT -5
Great brain fart! I'm going to have to make one of those. One caveat; chucks on drill presses are often a taper fit which means that they can come off when you pull down on them. It's happened to me when using the drill press as a milling machine. I had to ensure that I minimized the gap between the rotating tool and the table in case the chuck came loose. This web site is truly a brain multiplier.
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carloscinco
fully equipped rock polisher
Member since July 2008
Posts: 1,639
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Post by carloscinco on Jun 8, 2009 19:13:55 GMT -5
Does not rotate. I did see a treadmill motor that was mounted vertically at the edge of a work table. An aluminum disk was mounted on the shaft. The variable drive controls were still operable for the motor and voila! a variable drive disk. No reason you couldn't hook up a pulley to separate the motor from the disk and make it a wet lap. I've been looking for a broken treadmill with a working motor ever since.
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grant
noticing nice landscape pebbles
Member since March 2007
Posts: 85
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Post by grant on Jul 17, 2009 20:47:02 GMT -5
Hmm, I have on of those old drill press mounts for a hand drill, and I just realized I could mount up my Dewalt XPR 1/2" Battery powered Drill ( 3 speeds and it will sprain your wrists if you get it stuck), and use it at rockshows and such for demos and preforming arrowheads for Knapping. ;D
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NDK
Cave Dweller
Member since January 2009
Posts: 9,440
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Post by NDK on Jul 25, 2009 22:54:46 GMT -5
A good way to keep the plastic from melting would be to use a band saw to cut it. The blade moves much slower, so the friction wouldn't build up as quickly. I was too lazy to dig mine out, so I just used the jig saw. Lol... Also to make the disk more round, I just chucked it up into the drill and used a large bastard file to turn it down a bit (rough sandpaper wrapped around a narrow board would probably work too). It also smoothed the edges so I didn't have to worry about getting caught by a burr sticking off it while cabbing.
Nate
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Post by johnjsgems on Jul 25, 2009 23:16:11 GMT -5
The cutting board is likely flat enough for lapidary work. If not you could use 1/4" clear acrylic (plexi-glass). It is used as backing plates for faceting machines using ultra laps for polishing so I guess they are flat. I'm guessing a glass shop would be glad to sell scrap pieces pretty cheap.
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NDK
Cave Dweller
Member since January 2009
Posts: 9,440
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Post by NDK on Jul 26, 2009 21:14:49 GMT -5
Yup John, the cutting board works great. I have made all my (4) cabs on it. In fact, I'm thinking of getting another board to cut out disks for each grit size, as right now I only have one I switch from 100, 220, to 400, and another one with a craft foam backing for the 600 grit.
Nate
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