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Post by catmandewe on May 27, 2007 23:38:38 GMT -5
Got it running and cut some practice slabs today. There is absolutely no reason to put a pump on it. That thing throws oil by the gallons. I redid the clamp system 3 times before I got something I really liked, but I think I got it now. It got dark on me, so I didnt get any pictures of the finished saw, but I got some pictures of the slabs I brought home. Ill try to get some pictures of the saw tomorrow. I know the white ones are Bennett Hills Agates from around here, but I have no idea what the other two are, they were something I got out of the 20 cent/pound pile at a rock shop in Oregon.
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Post by deb193 on May 27, 2007 23:59:13 GMT -5
What was the biggest slab so far?
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Post by catmandewe on May 28, 2007 0:12:04 GMT -5
about 7" across 5" high. It went through it in about 2 minutes. I have never had a saw like this before, most of mine are tile saws that I use in my work and I get them out when I wanted to cut something. Any tips or info would be greatly appreciated. Like.........do you try to keep the glowing in the rock to a minimum, or let it glow away?
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adrian65
Cave Dweller
Arch to golden memories and to great friends.
Member since February 2007
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Post by adrian65 on May 28, 2007 7:20:37 GMT -5
I don't know if you're fully equiped for tumbling, but you are for sure for cutting! Great slabs! 2 minutes?? What was that, cheese? Did you see something through that plexiglass?
I don't understand what glowing means, are you talking about the sparks seen inside the agate while you cut them? If so, I know it's good not to have sparks (glows) at all. I didn't manage that but I try to reduce them as much as possible by decreasing the pressure. I've noticed you have a system with counter-weight. Try to diminish that counter-weight so the cut will slow down. Such a slab takes me for cutting at least 5...7 mins.
Be careful, overheating "kills" the blade. If the diamond particles included in the border metal are covered by melted metal, they don't cut any more. But there's a cure, it consists of cutting some thermo-resistant brick. Do that when you notice your blade is not so "aggressive" as it used to be.
Adrian
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Post by beefjello on May 28, 2007 10:21:00 GMT -5
Nice cuts from the Beast!
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Sabre52
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Me and my gal, Rosie
Member since August 2005
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Post by Sabre52 on May 28, 2007 10:44:46 GMT -5
Uh....My slab saw is slow on purpose to increase blade life ( I cut at a ten minutes per inch speed, or 6" per hour A fast slab saw is 15" per hour. You're cutting 150" per hour!). If you're cutting that fast, you are destroying your blade and if you're generating a lot of sparks, depending upon what type coolant your using and it's flash point as vapor, I'd be a bit worried about a closed system vapor explosion. Best thing is to slow the feed way down and just not to have sparks and have your blade last longer.....Mel
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Post by catmandewe on May 28, 2007 12:37:29 GMT -5
I backed the motor off until I couldnt see the sparks anymore, and it did slow the cut down considerably. I am experimenting with the old used blade, to get the feel for the saw, before I put the brand new one on. It is real easy to control the blade speed, and I have several different size weights to hang on the cable. I am using mineral oil for a coolant, there is 20 gallons in the reservoir, and the blade sits in the oil about 2-3 inches. There is enough oil on the blade to actually make a little jetstream spray where the blade enters the rock. You really cant see anything through the plexiglass, but there is a view hole right above the blade and the plexiglass lets in enough light so you can see whats goin on down there, you just have to watch out for the oil spray that comes out of the view hole sometimes.
Thanks for all the info guys, sure better to learn it here than by trial and error.
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Sabre52
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Me and my gal, Rosie
Member since August 2005
Posts: 20,487
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Post by Sabre52 on May 28, 2007 12:54:54 GMT -5
I guess I was not quite clear but it is not blade turning speed that is the issue ( though all lapidary blades do come with recommendations for optimum blade RPMs) but rather the speed at which the rock is fed into the blade. Saws with a power feed utilize a worm gear to make sure the rock is fed into the blade at a constant and correct speed to maximize blade life and prevent dishing or warping of the blade which will occur if the rock approaches the blade surface with excessive pressure. Excessive pressure at the blade/rock interface will only wear away your blade cutting surface very quickly and cause sparking and glazing of the blade, but it will also overheat the blade and cause it's surface to warp or curve so it starts to bind in the cuts and eventually become in need of repair or unusable. The blade should only be about 1/2 to 3/4 inch submerged in your coolant reservoir...Mel
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Post by catmandewe on May 29, 2007 14:50:28 GMT -5
Ok, I did some figuring and I have an almost 4/1 reduction in speed through my pulleys, the 4 hp motor runs at 3600 rpm at full throttle, which means the blade is spinning at about 900 rpm. Someone on here said earlier that I need to run a 30" blade at about 600 rpm, so assuming that is right, that means I need to go 2/3 throttle for the optimum rpm range. At 2/3 throttle with the lightest weight on the feed cable it takes 28 minutes to go through a 4" wide 6" tall rock. That puts the feed rate at about 8" per hour. That seems to put it closer into the range you are talking about Mel. Here are some pics of the new setup Here is the blade in the oil Here is the clamp setup Thanks for lookin and the feedback.
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Deleted
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Post by Deleted on May 29, 2007 18:46:27 GMT -5
Well I never thought it would work but great job! Looks like I owe you a piece of jade.
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adrian65
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Arch to golden memories and to great friends.
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Post by adrian65 on May 30, 2007 1:16:14 GMT -5
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