Why release the tension?

[Mark Singer]

I had a Trimaster break because it was tensioned all the time , now I un tension each day I work

[Frank Drew]

Jamie, automobile tires absolutely can develop flat spots if left too long in the same position without moving. And I'd expect to keep a band saw for decades, not a couple of years.

I didn't come up with the idea to release the tension -- Oliver, the maker of my last band saw, recommended the step when they sent back my wheels after replacing the tires.

[Bill Keehn]

I only use/have Timberwolf blades for my Steel City, so I do, but only because of this:

http://www.suffolkmachinery.com/six_rules.asp

Rob

Rob, yep thats the best reason I can think of to do it. The timberwolf blades are "special" low tension blades, so you would think if something requires detensioning those would. David Marks specifically mentioned he likes these blades, but went on to say how he ignores their recommendations and does what he feels gives him the best results, which is over-tensioning. If it shortens the life of the blade or tires, so be it. Relative to the cost of the woods he uses the parts are cheap and easy to replace.

I happen to use a 3/4" Timberwolf on my Jet 18" for resawing & cutting veneer and thats all I use it for. I took a veneer class from Marks at the local Woodcraft, so I decided to follow his example. Now if there were a Carter quick release for the 18" I'd probably use it just in case. That's what I did with my old bandsaw, a 14" Powermatic along with using Darl's idea.

[Sonny Edmonds]

I don't release mine.
Never have, probably never will.
It runs and sounds and cuts the same as when new. Maybe a bit better.
I did make it 240 volt and that made a difference.
Mine has a tension gauge. It in fact has proven to coincide with Timberwolfs tensioning advice. (Who's blades I run, mostly.)
Haven't broke any blades (Knock on wood )
And my wheels are as true as they ever were.
But hey, do what you will in your own shop.

[Paul Atkins]

Car tires may get a flat spot, but they only sit on one spot - the band saw blade sits on 1/2 of the wheel - on a 20" saw this is over 30" on each wheel - It may not be equal force all the way around, but that is 60" of contact for a 150" blade. I'm not sure you could get a flat spot. I know I might forget to tighten the blade each time I use it - so I don't loosen it. Plus it gets used every day.

[Andy Pratt]

I never did it with my bandsaw until I broke a blade, then I started it and haven't broken one since. Just one instance, so it's definitely not a controlled experiment or anything, but here are the details:

I think it was a 5/16" timberwolf blade, not positive though. I had left it tensioned, on the high side of the recommended setting, for about a month or so without using it. When I went to use it, the blade broke immediately on startup. Since then I've always released the tension (carter system) as that was the only thing I could think of that I had done differently than all the other times I had used it without breakage.

Again, this is just one instance and I'm certainly not sure it wasn't a faulty blade or that I didn't overstress it with the tension or my sawing technique, so take this for what it's worth.

Andy

[Steve Rozmiarek]

Well guys, for what it's worth, I'm going to continue my no detension "experiment", until something breaks. I will detension the big saw, but not the little one. Not expecting anything interesting to happen, but I'll let you know if it does.

[Rod Sheridan]

Well guys, for what it's worth, I'm going to continue my no detension "experiment", until something breaks. I will detension the big saw, but not the little one. Not expecting anything interesting to happen, but I'll let you know if it does.

I'm with your approach Steve.

I've never released the tension on a bandsaw at home, or at work, and have never experienced a problem.

The only rolling element bearing problem I've seen happen to stationary bearings is Brinelling, and that's only happened to stationary bearings that are subject to vibration or shock loads while not rotating.

regards, Rod.

[Steve Rozmiarek]

I'm with your approach Steve.

I've never released the tension on a bandsaw at home, or at work, and have never experienced a problem.

The only rolling element bearing problem I've seen happen to stationary bearings is Brinelling, and that's only happened to stationary bearings that are subject to vibration or shock loads while not rotating.

regards, Rod.

Rod, I'd suspect that Brinelling is wear on one spot of a roller bearing, kind of a flat spot, correct?

[george wilson]

I have had a Delta 14" bandsaw since 1964,when I bought it used. I never release tension,and am afraid to,because my wife (who dosn't mix with machinery well) uses the bandsaw to cut plastic. I just know she would start the saw up with the blade slack. Take my word for it! Anyway,no problems have ever developed for mr. I still can't say that releasing tension isn's a good idea,seems logical,but it hasn't hurt me for many decades.

[Jim Chilenski]

Steve,

I believe that the "release the tension" thought came about because of the number of failures of the tracking arm that holds the upper wheel shaft on a 14" Delta bandsaw. This is the triangular piece of alloy die casting that is hinged to the tension control housing.

What will happen over time is that excessive tension will cause the hole that the shaft passes through to become elongated, making it harder to keep the blade tracking true. Once this occurs the only solution is to replace the assembly.

This has been identified as the "weak link" in the Delta 14" design. Iturra Design markets a beefed up version of the tracking arm and tension control housing which is suppose to hold up longer.

But I suppose that over time, with enough tensioin, it can fail as well.

YMMV
Jim

[Joe Von Kaenel]

Steve,


I read "The Band saw Book" by Lonnie Bird and "The New Complete Guide to the Band Saw: Everything You Need to Know About the Most Important Saw in the Shop by Mark Duginske. Both authors recommend detensioning the blade to save wear on the tires and the bearing. I bought a Carter Quick Release™ because it was such a pain to tension and retension the blade. This item works by moving an arm down to release the tension and moving it up to retention the blade.

It sounds like a lot of Creekers don't detention theirs blades and don't have problems. This is just a method I use. Hope this helps.
Joe

[Jeffrey Makiel]

For over 20 years, I've never de-tensioned a blade when not in use. And, my bandsaw is only used intermittently in my hobby. I've grouped this practice in the same category as PVC duct blowing up my home, polyurethane glue being stronger than yellow glue, and using blade stabilizers on my tablesaw to reduce vibration.

However, I do wear a garlic clove around my neck when doing final assembly.

-Jeff

[Rod Sheridan]

Rod, I'd suspect that Brinelling is wear on one spot of a roller bearing, kind of a flat spot, correct?

Yes Steve, it's actually a depression in the outer race the same shape as the rolling element (ball or roller).

Obviously the bearings are fine with the static loads imposed upon them, it's the "hammering" effect of vibration that causes Brinelling. (Often seen on bicycle and motorcycle stearing head bearings).

Regards, Rod.

[george wilson]

I wonder if the tension release arm is just something else to make us think we need it? And,does the blade stay in contact with the wheel when it is detensioned? Does the blade fly off the wheel when you retension and start the saw? Either way,I KNOW my wife would never remember to retension the blade. She uses the bandsaw once every several months.My wife has other talents,don't get me wrong. She runs our home business(mostly her's) very well.She has incredible ability to find some obscure article in a 1940's magazine that I looked at 5 years ago (and showed her),now lost in hundreds of old magazines. We are a team. Each helps the other's weak points.