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I've had a Jet JWBS 18 band saw for 20 or so years.  It's mainly used for resawing.  Moving to Florida forced me to start working with some pretty tough woods  and the bandsaw has been challenged a lot.

Thinking bigger is better, I bought a 1-1/4" x .042" bandsaw blade.  Shouldn't be a problem since Jet says the saw can handle up to 1-1/2" wide blades.  But that brand new, carbide tipped blade really struggled with 6"-9" wide zebrawood.  So out looking for answers.  In the process I realized I will never really know the answer until I buy or build a tension gauge.  So I built one.

BSTensionGauge_001.thumb.jpg.0775a30712571db2675998a7dc495196.jpg

In order to have 15,000 PSI of tension, the needle needs to move .002 on the dial.  After cranking it all the way, this was it.

BSTensionGauge_002.thumb.jpg.b92daa211ee1de59f6a45fe82ba65f2b.jpg

Which means the saw can only tension the blade to a little more than half what is needed.  Or maybe I don't know how to read a dial indicator.

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This isn't my area of expertise, but as an engineer I do math all day. 

You wrote:

In order to have 15,000 PSI of tension, the needle needs to move .002 on the dial. 

Can I check your math on that calculation?  Not saying it is right or wrong, but checking math is an easy first step. 

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Alex Snodgrass is a good resource for everything related to bandsaws.  This video is probably not what you are looking for, but he has several more that may give you what you need.

I'm guessing less TPI would help for resawing.

 

 

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Trying to measure a small elongation directly over a short distance accurately and reproducibly is challenging, especially with the indicator reading off a wooden surface.

I'd suggest moving the indicator 90 degrees to the blade and placing a known deflection force on the blade opposite the indicator contact point. Then measure the deflection of the blade using the indicator and use trig to calculate the blade tension. A few minutes with a spreadsheet should let you come up with a table of tension as a function of deflection measurements at a given deflection force.

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32 minutes ago, More Cowbell2 said:

I'm guessing less TPI would help for resawing.

That's what I thought - that blade looks awfully fine toothed for ripping.

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57 minutes ago, NaptimeAgain said:

Have you tried a carbide tipped blade? 

The blade is a Lenox Tri-Master - carbide tipped.

6 minutes ago, SloopJonB said:

That's what I thought - that blade looks awfully fine toothed for ripping.

For as long as I've been doing this, there have been people who pay little or no attention to TPI.  I agree, it makes sense larger gullets would clear more waste out, and that's where I started way back when.  When I ordered Tri-Master, I thought I ordered the 2/3 TPI, which is the widest tooth separation they offer for that blade, but it arrived with a 3/4 TPI.   My first Lenox blade was a Woodmaster CT with 1.3 TPI.  That worked pretty well for a while but it still dulled fairly quickly, for a carbide tipped blade.

The culprit may simply be tension.  It appears my saw cannot tension that beastly blade enough for a good resaw.  From what I've read, the blade for my saw should be no wider than 3/4".  Not sure if that includes the teeth or not.  But I had a 3/4" wide Laguna Resaw King (also carbide tipped) in there when this job started.  It hadn't been used all that much but after a few passes of zebrawood, it started drifting badly.  That thing ran almost $300.  I have more money in blades now than the saw originally cost me, and it was new when I bought it.

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1 hour ago, Jules said:

I've had a Jet JWBS 18 band saw for 20 or so years.  It's mainly used for resawing.  Moving to Florida forced me to start working with some pretty tough woods  and the bandsaw has been challenged a lot.

Thinking bigger is better, I bought a 1-1/4" x .042" bandsaw blade.  Shouldn't be a problem since Jet says the saw can handle up to 1-1/2" wide blades.  But that brand new, carbide tipped blade really struggled with 6"-9" wide zebrawood.  So out looking for answers.  In the process I realized I will never really know the answer until I buy or build a tension gauge.  So I built one.

BSTensionGauge_001.thumb.jpg.0775a30712571db2675998a7dc495196.jpg

In order to have 15,000 PSI of tension, the needle needs to move .002 on the dial.  After cranking it all the way, this was it.

BSTensionGauge_002.thumb.jpg.b92daa211ee1de59f6a45fe82ba65f2b.jpg

Which means the saw can only tension the blade to a little more than half what is needed.  Or maybe I don't know how to read a dial indicator.

have you called tim allen?

 

is there going to be a band saw blade tensioner thread?   asking for a friend..

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First off, the wider the blade, the more friction you have, the hotter the blade and board get, the harder the saw works..... I've found it best to use a 1/2" 3-4tpi skip tooth blade for resawing most wood. Wet White Oak it's better to have a 1" 1-2 Tpi Variable pitch blade.

 Make sure your thrust bearings are set properly, and your guide bearings/blocks are just a tissue paper off the sides of the blade. I had a Jet 14" for a very short time. I found it (as well as the Jet tablesaw) vastly under powered. Make sure that your wheels are co-planar, and that the blade is set on the tires properly. And when resawing anything over 6", drive slow.

 I've put more miles on bandsaws than most people, and I learned how to tune them up, from an old Sears 10" saw to a Delta 14" saw (With riser block) to a Rockwell 20" saw with a welder, to an Oliver 30" beauty from 1926.... They all needed tuning up. The only one I got new out of the box was the Delta 14", and that took about 2 days to set up, and tune up.

 The only one I have now is the Rockwell 20" and even after all the travel it's been through, a couple of hours of tuning, and new bearings for the guides, and I can reliably cut 3/16" veneers in 8" hard Maple.

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Oh, and BTW, Carbide blades are great for gritty, or silica laden woods, but are never as sharp as a good quality HSS blade. I get my blades from Suffolk Machine on Long Island. Try the "Timberwolf" brand.... Excellent blades.

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13 hours ago, welder said:

Isn't that a little over .013" so way over

Yep, that's how I read it too, and I use dial indicators ALL THE TIME. Generally so as to get things set up in the lathe with zero runout or as close as needed.

There's a .013" difference between the first pic and the second one.

Mind you, wood clamps, flexy machine - who knows really. I've an 18" heavy duty Grob Bros wood/metal cutting bandsaw, I think it'd struggle to run a blade that wide.

FKT

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I've never had much use for hook tooth blades unless I was slicing up thinner boards.

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