docharber
has rocks in the head
Member since October 2008
Posts: 693
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Post by docharber on Mar 21, 2009 20:45:45 GMT -5
I am considering a gravity feed 10" saw. How much weight dio you use for these machines? is there a way to calculate it. I assume it would vary by the kerf width, size and type of material being cut, too. I am saw shopping and will need to know if I buy a gravity feed saw used without a manual., Thanks... Mark H.
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Post by johnjsgems on Mar 21, 2009 21:23:59 GMT -5
Mark, I suppose someone here has the weight needed but from my own experience on two ten inch saws I've owned I just hand fed. With a good lapidary blade and the 3"-3.5" maximum height you can gently push a rock through pretty quickly. If you wanted to use the gravity feed I'd advise the least amount of weight that will pull it through. Your blade will love you. If you do hand cut you can quickly become accustomed to the saw bogging down from using too much pressure. Set up the gravity weight to keep it from bogging down by the sound. Some people will (by trial and error) find the weight needed for various hardness rock. Then using a plastic milk jug you can mark water levels for different rocks.
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docharber
has rocks in the head
Member since October 2008
Posts: 693
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Post by docharber on Mar 21, 2009 21:51:20 GMT -5
I have heard of the milk jug trick. I have an awful habit of destroying blades so for anything ove a half inch I think gravityy feed might be a good idea. I tend to find myself pushing harder and harder as I cut more and more stones. i have greatly reduced mny blade mortality by focusingh on just apllying enough pressure to keep the stone from chattering and dancing around. It take way longer but the blade holds up much better. I have ruined 4 blades on my trim saw and tile saw. I was almost happy to read that Bikerrandy wore out a 10" blade in a sitting recently. i guess I'm not alone. I'm bidding on a saw on eBay now, and it's a gravity feed "mercury" with a blade. I have a motor so I'm set. I am still planning to buy alarger saw, but this was so cheap I couldn't resist. Hope I get it.
Mark H.
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Post by johnjsgems on Mar 22, 2009 10:12:15 GMT -5
10" is a great size. When I got in the hobby I was told if I only had one saw get a 10". Trim or slab fist sized rocks. You already have the smaller trim saws. I am also heavy handed but learned to feed gently on my first saw because the motor was on it's last leg and would overload if I wasn't gentle. Remember you are grinding through a rock not cutting. Allow the diamond blade to do it's work. Your job is only to advance the rock as the blade grinds.
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Mudshark
fully equipped rock polisher
Diplomacy is the art of saying 'Nice doggie' until you can find a rock. Will Rogers
Member since December 2008
Posts: 1,083
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Post by Mudshark on Mar 22, 2009 13:05:24 GMT -5
Mark,I just dug up the instructions for my Covington 10 inch saw.It says for every inch of blade contact use four pounds of weight,and not to exceed 10 pounds total weight.So if you are cutting a rock 2.5 inches thick you could go up to ten pounds.I rarely used that much weight when I was using the weight feed because it would eat the blades too quickly.I finally bought the power feed system and love it.It cuts at a very slow rate and the blades last a lot longer.I think building a power feed would be easy,all you would need is a low rpm motor and a piece of threaded rod and a split nut.A motor off a refrigerator ice dispenser should work fine.I made a split nut for my bigger saw from a spring clamp with a couple of pieces of pvc in the jaws that I drilled and tapped.This could be adapted to just about every saw. Mike
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docharber
has rocks in the head
Member since October 2008
Posts: 693
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Post by docharber on Mar 22, 2009 18:38:45 GMT -5
Thanks, Mike. In spuite of being educated otherwise, I slabbed up about 15 lbs of assorted agate and jasper today and wore out my work force replacement blade. I started on a new Hot DOg and I think I nearly wore it out, too. I can tyyell by the way the saw chatters and vibrates as it qwears out. The sooner I get away from hand feeding the better for my budget,. and the invvestment in a power feed saw is lookingbette every day. I lost the auction last night on the Mercury saw after bidding up to $210- It had a decent blade and was probably a good deal. Should have bid more. Anyway, I'll keep on looking. I want a vertical cabber, too so the budget is a major consideration. I should also consider smasking my finges with a crack hammer so I won't be tempted to push so hard. I start out easy and end up in too much of a hurry.
Mark H.
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Mudshark
fully equipped rock polisher
Diplomacy is the art of saying 'Nice doggie' until you can find a rock. Will Rogers
Member since December 2008
Posts: 1,083
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Post by Mudshark on Mar 23, 2009 15:13:22 GMT -5
Mark,I dont know what it takes to win a 10 inch saw on ebay but I bid on at least a dozen saws over a six month period and lost every time.The dang things hold their value better than a Harley.I finally figured if they hold their value so well I might as well bite the bullet and buy a new one. 15 pounds is a lot for a seven inch blade so I think you did ok on that.I just bought the Lowes equivalent of the workforce saw and am real happy with it.I cant imagine cutting 15 pounds in one day.I just dont have that kind of patience.
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docharber
has rocks in the head
Member since October 2008
Posts: 693
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Post by docharber on Mar 23, 2009 21:45:11 GMT -5
I appreciate that- I feel less incompetent already! I am beginning to think a new saw is the best bet, too. The Scottish blood heats up when I even think of paying a grand or more for a little box, arbor, blade and motor. But, if I must- my daughter's braces will just have to wait.
mark H.
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