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View Full Version : Proper tension on a bandsaw blade



Gene Hintze
02-18-2013, 4:46 PM
I am a turner and usually hang out on that forum but I have a bandsaw question and this seemed the appropriate place for it. I purchased an older (1990) Jet 14" bandsaw that needs a good going over before it will be functional. It runs but a significant tuneup is in order. The question I have is how to properly set the tension for the blade. There are no markings on the tensioning mechanism to use as a guide. Any suggestions would be appreciated.

Alan Schwabacher
02-18-2013, 5:04 PM
If you want to tension to a known value, Phil Thien's approach is probably the most effective: http://www.jpthien.com/tg.htm
He uses the sound of a plucked blade to determine tension, given a few parameters. It's cheaper and probably more accurate than other methods.

My experience is that tension is not too important. Add tension until the saw works well without fully compressing the spring. If you get your saw working and make a pencil mark, you'll be able to repeat what worked, which is more helpful than knowing what the tension is.

If you have trouble with the saw, you may want to measure to be able to rule out tension as the problem. My guess is that most saws that have trouble cutting well have other problems than just tension.

Gus Dundon
02-18-2013, 5:29 PM
If you want to tension to a known value, Phil Thien's approach is probably the most effective: http://www.jpthien.com/tg.htm
He uses the sound of a plucked blade to determine tension, given a few parameters. It's cheaper and probably more accurate than other methods.

My experience is that tension is not too important. Add tension until the saw works well without fully compressing the spring. If you get your saw working and make a pencil mark, you'll be able to repeat what worked, which is more helpful than knowing what the tension is.

If you have trouble with the saw, you may want to measure to be able to rule out tension as the problem. My guess is that most saws that have trouble cutting well have other problems than just tension.

Wow. That's a very helpful method. I am always doing a manual routine in putting right tension on my blade. Plucked it like a guitar and listen to its tone or use a simometer.

Nick Lazz
02-18-2013, 10:13 PM
I agree with Alan...but I am not an expert. I tension my blades even more simply..until the vibration is out and it 'feels' like the blade is cutting as best it can. I usually tension it and push on the side of it so it has less than 1/8" deflection.

P.S. many bandsaw blades that you buy will have a recommended technique on how to best tension their blades. I use both the Woodslicer and Timberwolf and both have instructions with their blades.

Curt Harms
02-19-2013, 7:01 AM
I use the Timberwolf recommended technique on non-Timberwolf blades as well. I use a little bit of a twist, however. My Rikon 10-325 has a window in the top door to make the blade tension gauge visible. The tension gauge is of limited use IMO, it seems to indicate wheel position rather than blade tension. However, I can look in the top left corner of that window when the saw is running and see the band. If it's too loose, it 'vibrates'. I tighten til it stops then maybe half a turn more. That seems to work pretty well for carbon steel blades. I imagine bimetal or carbide tipped would be another matter.

John Bailey
02-19-2013, 7:41 AM
My Oliver 192-D is a bandsaw in Eb. I use my guitar tuner, pluck the band and when the tuner shows I'm planing an Eb, I know the tension is good. I've done this with both 1/4" and 3/8" blades and works for both. Other blades and bandsaws may be different, of course.

John

Chris Padilla
02-19-2013, 1:10 PM
I go for 1/4" or less of deflection pushing on the blade at the table. Seems to work well for me but honestly, it probably doesn't matter a whole lot. What is more important is coplanar wheels and properly set-guides to give a smooth running blade that cuts straight without any (silly) drift adjustments. :) Also, a big duh, but a good sharp blade. If you find issues with your saw, the easiest first step is to change blades to see if the problem persists. There are plenty of lemon blades out there that will have a perfectly tuned saw cutting lousy.

Myk Rian
02-19-2013, 1:16 PM
The flutter method has never failed for me.

Curt Harms
02-20-2013, 8:56 AM
I go for 1/4" or less of deflection pushing on the blade at the table. Seems to work well for me but honestly, it probably doesn't matter a whole lot. What is more important is coplanar wheels and properly set-guides to give a smooth running blade that cuts straight without any (silly) drift adjustments. :) Also, a big duh, but a good sharp blade. If you find issues with your saw, the easiest first step is to change blades to see if the problem persists. There are plenty of lemon blades out there that will have a perfectly tuned saw cutting lousy.

True that.

Gene Hintze
02-20-2013, 12:11 PM
Thanks for all the input. I believe my question has been answered.