Bandsaw blade tension

[Jim Onofrio]

I've read various articles regarding removing the blade tension on the bandsaw when not in use. Can someone tell me what the real scoop is? Thanks!

Jim Onofrio

[Pete Bradley]

Boooooogus! A buddy of mine with a professional shop laughed at me when I asked, and I almost never do unless I know the saw's going to be idle for a week or more. I've even seen comments about "taking the load off the bearings" which is patently ridiculous since you'd also have to loosen the belts and any number of ball bearing applications involve constant load.

But if you want more information search the archives for "detensioner". It's a common feature on recent model hobbyist-oriented machines.

Pete

[Roger Ronas]

My opinion is that if your not going to use the saw for quite awhile then I would detension it.
But if your using day after day, I wouldn't.
Shouldn't matter to the bearings, the tires may get flat spots if not used for awhile, but I don't see that happening overnight.
JMHO though!

rCR

[Tom Veatch]

Pete and Roger both have valid points. In a "professional shop", assuming daily or near daily operation, detensioning the blade wouldn't gain you anything. In an environment where the saw sits unused for long periods of time and depending on the type of material in the tires, it's possible to get "cold flow" flattening/thinning on that half of the tire that is subjected to unrelieved pressure.

No, I don't know what material might be less or more subject to the effect nor can I say from my own experience how long it would take to show any significant deformation. My practice is when I know i'm not going to be using the bandsaw for several days or more, I'll back the tension off if I remember to do so. Don't figure it hurts anything to relieve the tension/pressure on the tire and might help.

[Charlie Plesums]

Both the blade vendors and the saw vendor recommend detensioning my 14 inch hobby-grade bandsaw. It makes sense, since I normally have a fairly narrow (1/4 inch) blade on the relatively soft crowned rubber tires.

The instructions on my commercial grade 24 inch bandsaw say to detension the blade, but I rarely do. I normally have a fairly wide 1 inch blade on the extremely hard, flat tires. I have noticed that if I leave the blade tensioned through a period of non-use (such as a few weeks for a project that doesn't use the big saw), when I go back to using it, I have some vibration in the blade that gives a rough cut. After running for a while the cut improves again. Therefore if the machine will be idle for a while, I try to remember to detension it.