Blade tension

This may be a stupid question but how or what is the proper way to determine the correct blade tension on a bandsaw? I think my last blade broke due to it being too tight, but not certain. I want to make sure I don't do it again.

Thanks

Reply to
Meanie
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See:

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can make a DIY version. Something on my 'to make' list.

Reply to
GarageWoodworks

On the other hand, Michael Fortune, also in Fine Woodworking, suggests with a 1/2" blade, set the tension to the mark for 3/8" using your your saw's tension gauge. In other words, less tension than Lonnie Bird recommends is OK if your saw is otherwise set up correctly and you feed the work through slow enough that the blade can clear out the sawdust.

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Reply to
Jim Weisgram

Thanks for posting that! I do think he exaggerated a little at 5:15. Not sure he is going to be able to discern 1 thou gap btw the blade and guide bushing by eye.

Reply to
GarageWoodworks

Thanks for posting that! I do think he exaggerated a little at 5:15. Not sure he is going to be able to discern 1 thou gap btw the blade and guide bushing by eye. ============================================================================== Depends what he does for a living. I can.

Reply to
CW

"Meanie" wrote in news:k2gqu8$u2a$ snipped-for-privacy@dont-email.me:

There's several methods for tensioning blades, and it depends on what blade you're using as well as your saw. To summarize:

The "pluck" method: The blade is tensioned until there is a clear note heard from the blade when it has been plucked with a finger.

The flutter method: The blade is set to some initial tension then the saw is turned on. The tension is adjusted until the blade flutters then stops fluttering. You'll have to do some reading on this, as this is only a very basic description of the method. I believe Timber Wolf blades recommend this method.

The "press" method: The blade is tensioned until pressing the blade gently results in a certain amount of deflection.

Checking the gauge on the back might be effective as well, but the gauge doesn't really measure anything. It essentally shows you how much your spring is compressed, but not the pressure it's exerting on the blade. If your saw is in good condition, there's no reason this won't work properly.

Puckdropper

Reply to
Puckdropper

Pete,

Do you think it would be particularly difficult to make the tension gauge in the picasaweb site? Seems like a nice project.

I was looking for ideas for a DIY band saw blade tensioner today and came across this one:

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think I am going to try and make it. It looks like the lower part of the device pivots on a bar and the movement is measured by the dial indicator. It looks like the bar would have to be exactly in the center to be accurate.?. According to a FWW article I read, 5" of blade will stretch

0.001" for every 6,000 lbs of tension (over a 5" length of blade). For those with a FWW account here is the article:
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don't like the one detailed in the article (I prefer a dial indicator over feeler gauges).

Has anyone tried to make one of these before? Or have you made a better one??

Thanks...

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You may want to look at this version of Bird's commercial gauge.

Jim

Reply to
Jim Artherholt

What works for me is to start with the "built in" tension gauge on your saw. Test cut, tighten a bit, test cut, is it better, worse?

As blades wear they require different settings. Use your built in gauge as a starting point and tweak from there.

Reply to
Leon

On Sun, 9 Sep 2012 04:00:10 -0600, Jim Artherholt wrote (in article ):

I used this method for my Minimax and with 12" of blade exposed, I used a dial indicator that measured down to 0.00001". With this resolution I could get a clear reading of tension, then marked my saws tension scale (which was reading wayyyy low). I really doubt a standard 0.001 dial gauge set at 5" will provide much accuracy. But.....

I've come to realize that being super accurate is way overrated and once you have a blade tensioned properly as a reference, you can do it from now on using the 'pluck test' or deflection tests with perfectly acceptable results.

-Bruce

Reply to
Bruce

Agreed - that's what I do. "Twang" is good, "plunk" is bad - but if the blade hits high C it's too tight :-).

Reply to
Larry Blanchard

This isn't complicated enough for most, just pluck the blade when it is about the tune of E it is close, works for everything from 1/4" blades to

12" wide bandmill blades in a sawmill.

basilisk

Reply to
basilisk

Does that mean I need a blade tensioner AND a tuning fork? ; )

Reply to
Meanie

It just means that you have to become familiar with your band saw enough to know when it's not tracking properly and the blade tension needs some maintenance.

Reply to
Dave

There's always feeler gauges.

Reply to
Jim Weisgram

Jim Weisgram wrote in news: snipped-for-privacy@4ax.com:

I've seen suggestions (Either in Bird or Duginske's book) for using dollar bills or other pieces such pieces of paper. I can't seem to remove the "gauge" without messing up the adjustment.

I set the side blocks by setting them to touch the blade and then back off a hair. It might be farther than the gauges would have set, but it works for me.

Puckdropper

Reply to
Puckdropper

I have roller blocks on my Delta, and set them so they just barely turn when there's no pressure other than tension on the blade.

Reply to
Dave Balderstone

Michael Fortune suggests cigarette paper rather than dollar bills. That may be splitting hairs as well.

Reply to
Jim Weisgram

Jim Weisgram wrote in news: snipped-for-privacy@4ax.com:

Cigarette paper is close to 0.001" thick. Standard printing paper is ~

0.002" thick, and a dollar bill is a bit thicker. Not exactly calibration standards, but machinists used to use cigarette paper to check cutter clearance. You crank the cutter down/in until you can feel it catch between the tool and the work, and that gets your zero plenty close enough for most work.

Doug White

Doug White

Reply to
Doug White

On Tue, 11 Sep 2012 18:46:22 -0700, Jim Weisgram

Might be cheaper too. :)

Reply to
Dave

Sorry, but you have to specify if that's a messaging test or a blade tension test.

Reply to
Dave

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