Band Saws

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PeteThePen1
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Band Saws

Post by PeteThePen1 » Sun Nov 18, 2018 5:43 pm

Hi Folks

I have the Clarke version of the ubiquitous 6" metal cutting band saw. It is a tool that I wish I had got many years soon than I did, despite its poor level of accuracy and flimsy frame build.

Since assembly I have wondered what speeds I should use for different metals or woods. The manual makes no mention of the opportunity to change speeds and I have not found any advice elsewhere. The options offered are shown below:
Saw 2.jpg
Saw 2.jpg (158.54 KiB) Viewed 458 times
I have always played safe and used the middle speed. Your observations would be welcome.

Pete

Sorry about the giant photo - will edit when I get back to the Desktop PC
Mike Rometer
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Re: Band Saws

Post by Mike Rometer » Sun Nov 18, 2018 8:12 pm

H Pete, I'd often wondered what the speeds were on mine. I've got the pulleys, just not the label with the speeds! Now I know! Ha Ha! True acuracy from a band saw is largely in the lap of the gods (unless very expensive) so I wouldn't worry too much on that score, just allow plenty. As a general rule the harder the material, the slower the speed, but the type and quality of blade has some bearing on that. I also mostly stick to the middle speed for most things.
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Lopez Mike
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Re: Band Saws

Post by Lopez Mike » Mon Nov 19, 2018 2:41 pm

Heat is your enemy. When you go too fast, the chips harden and you start actually loosing teeth on the blade. Unless you are pressed for time, I'd put the thing in the lowest gear and leave it there. Another thing is to cool the blade when ever possible. Oddly enough, water is one of the best but corrosion is an issue. Water/oil emulsions have been the standard but there are new things out there.

I'm speaking of ferrous materials here. When you are cutting stuff like aluminum and wood, the sky is the limit pretty much.

I'm lucky enough to own a 1939 Walker Turner with a back gear and continuously variable speed so I can slow down to below 20 f.p.m. when dealing with horrid things like S.S and crank the beast up to 2000+ when cutting aluminum and wood.

Buy good blades and keep the heat down. Obviously use fine enough blade pitch to keep a few teeth working at any instant.
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Re: Band Saws

Post by RGSP » Mon Nov 19, 2018 8:53 pm

Lopez Mike wrote:
Mon Nov 19, 2018 2:41 pm
Heat is your enemy. When you go too fast, the chips harden and you start actually loosing teeth on the blade. Unless you are pressed for time, I'd put the thing in the lowest gear and leave it there. Another thing is to cool the blade when ever possible. Oddly enough, water is one of the best but corrosion is an issue. Water/oil emulsions have been the standard but there are new things out there.

I'm speaking of ferrous materials here. When you are cutting stuff like aluminum and wood, the sky is the limit pretty much.

Buy good blades and keep the heat down. Obviously use fine enough blade pitch to keep a few teeth working at any instant.
100% good advice. Cast Iron needs a very low speed as well as 316 stainless, particularly cheap cast iron with inclusions. To be fair, with a coolant stream you could go up to the middle speed setting, but the removal-per-cut needs to be significant or the uncut surface will just harden. With a small, low powered saw the motor may not cope with the depth of cut needed, and the bottom speed will be better.

Free-cutting mild steels, most structural mild steels (which cut messily) and 304 stainless will be OK at the middle speed, particularly with coolant.

Harder grades of aluminium will be OK at all speeds, but the softer and more malleable ones are inclined to "flow" round the saw teeth and weld to them: coolant is again useful as a non-stick agent, but a high speed will also help.

Wood is almost always best at the highest speed possible, the only exception being when curved cuts are being made into some abrasive woods, which can scorch at high speeds. Scorching rarely goes deep, and can usually be sanded off easily, but lowering the blade speed helps as well, though only really when using a vertical bladed saw.
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