Thread: Blade Tension

Give Henry Bro's a call.( It does depend on the blade.)

Check this out, might be of interest

http://www.homemetalshopclub.org/news/jun02/jun02.html

Thanks Sprog.
What a bunch of frea......

I tried ringing Henry's, but it was too late in the day on a Friday. Bugger is, I only rang them 2 days ago when I was ordering some new blades. (Couple of 1/8" 14 TPI, and a 1/2" bimetal 3 TPI blade).

If you have Taunton "New Best of" series book on shop machinery, there is an article by Mario Rodriquez on making your own tension guage, measuring the stretch with feeler gauges. Based on that, I have a 'get round to it' project to convert one of the plastic digital verniers into a tension gauge.

I was looking at the commercial ones, but all they are is a standard dial guage with a new face pasted on in a basic frame with a couple of bolts to clamp to the saw blade. There is a new one out that uses some sort of pressure sensing pad, but it will only work on some bandsaws as it goes between the frame & the spring.

Good point - hard part would be calibrating it. On that though - given a dial gauge is around $80, shouldn't a bandsaw tension gauge be about the same price?

Like the idea of a homemade variety......now where did I put my copy of Google....?

You don't need a gauge, 80% of bandsaws don't have them there is a message in that

Stu, checkout Taunton's site, I think I read an article there about measuring stretch in the blade & relating it to tension.

I've heard of using cheapo digital verniers clamped to the blade, open jaws to an arbitrary figure, clamp top & bottom jaws to blade, then tension 'til desired stretch is achieved.


Cheers.............Sean

I use a combination of a thumbnail and a calibrated ear.

Maybe a guitar tuner and a plectrum... Try B#

Wouldn't the "desired" note vary with width, length & thickness of the blade?

I'm another who plays the BS by ear. I simply back off the guides and tension until I get a nice note (any note!) instead of a dull twang/thud/rattle.

Had no problems with stretch or bow-cut veneers yet. [fingers Xed. ]

Is tension really that important? In a Fine Woodworking article by Michael Fortune (December 2004), he suggests undertensioning enough that the blade deflects about 1/4" without the fingertips going white (blade stationary of course or fingers go red!:eek::eek::eek:. I've been using this technique with no problems so far other than adding a little more tension to stop the blade slapping against the back of the frame on one blade.

I think that it depends on the saw. I bought a gauge from Louis Iturra in Florida when I first got my 24" saw and was having difficulties. I have used it twice to calibrate myself WRT tension. It turns out that the 1" Lenox blade that I installed last year is staying on the saw, and the tension stays on too, so the gauge may not see much use. Frankly, the quality of the cut and the blade tracking should be your guide to tension*

*unless, like me, you are of the 'more is better' school. A big saw can easily over-tension a 1/2" blade. Blade failure and weld rupture is an experience not soon forgotten.

Greg

Originally Posted by TTIT

Is tension really that important? In a Fine Woodworking article by Michael Fortune (December 2004), he suggests undertensioning enough that the blade deflects about 1/4" without the fingertips going white (blade stationary of course or fingers go red!:eek::eek::eek:. I've been using this technique with no problems so far other than adding a little more tension to stop the blade slapping against the back of the frame on one blade.

Surely that would depend on how much blade is exposed between the guides though...

Cam

Originally Posted by CameronPotter

Surely that would depend on how much blade is exposed between the guides though...

Cam

Cam- He's referring to a 14" saw so I suppose he means with the guides in the uppermost position. When I got my saw (16" Hafco), I was told you had to wind up the tension until all the spring was fully compressed then another couple of turns for good measure. I found this was twisting everything and I couldn't 'tune' the drift out of it or keep anything constant. Since slackening off a bit, drift adjustments have been much easier to make and hold.