Bandsaw blade tension

Bruce Moffitt

Member
Messages
34
Location
Ottawa, Ontario, Canada
I recently purchased a grizzly G0555X and added the riser kit. This is my first bandsaw and I'm not sure if I have the tension set properly.

I tried to follow the instructions in the manual.

"Release the tension one quarter of a turn at a time. Do this very slowly. When you see the bandsaw blade start to flutter, stop decreasing the tension. Now, slowly increase the tension until the blade stops fluttering, then tighten the tension one more quarter of a turn."
I must be doing something wrong (old eye's) because I can't see the blade fluttering.
Help!!!!!!!:dunno:
 
Bruce I hope you don't mind but, without answering your question, may I add an additional question to it?

Assured your answer is yes; Is it best to relieve tension on a bandsaw blade between uses?
 
frank your questions answer is: yes,,, it saves the tire from taking a set and inducing early failure..which is what maintains your accuracy of cut to some extent
 
fluttering

bruce mine arent as old as yours but i can have troubles too at times,, there was a article in wood magazine a while back that described this adjusting thing very well.. i go by the feel of the tension and a cut against it i belive there sis another way of checking by using the guides all the way up and testing the deflection of the blade by hand and adjusting from there,, but older hands may have lost the strength as well so look for the wood mag azine ad
 
Frank - Yes.
Bruce - Are your guides completely backed off while you attempt to find the flutter spot? When I reach the flutter spot on my saw, if the guides were in place they would prevent the flutter. When I hit the flutter spot, there is no problem seeing it. It is quite unnerving and kinda dangerous looking ;-)

Here are the complete instructions from Suffolk specific to their Timberwolf blades but I do the same thing for any non-specialty (carbide, bi-metal) blade:

FOR TURN SCREW AND SPRING TENSIONING MACHINES
  1. Remove guides--you CANNOT run this test if the band saw blade is restricted in any lateral movement.
  2. Make sure tire surfaces are in good condition--they cannot be hard, flattened out, cracked or brittle. On mills with loose fitting V-belts, replace them with the next size down so they are tight fitting. This will eliminate over 80% of the vibration in your mill and the blade.
  3. Mount the blade on the machine and apply the tension to the band that the manufacturer recommends for other steels.
  4. Close all covers for safety purposes.
  5. Start the machine, engage the clutch into the high speed cutting mode. NOTE: You will not be cutting any wood.
  6. Stand at the head of the machine, with your hand on the turn screw tensioner and your eyes on the band saw blade. Very slowly start detensioning by half turns at a time, keeping your eyes on the band saw blade. The object is to bring the tension of the blade down to a point that the blade starts to flutter. TAKE YOUR TIME.
  7. When you see the band start to flutter, you have hit ground "ZERO". Now start ADDING quarter turns of tension, SLOWLY, until the band stops fluttering and is running stable again. At this point ADD one-eight to one-quarter turn of tension.
  8. You have now tensioned our blade correctly. Shut off the machine and put your guides back in place. You are now ready to start sawing.
  9. ALWAYS DETENSION YOUR BAND SAW BLADES. Since you do not know exactly where the proper tension is, it will be easier to remember if you take off 8, 9, or 10 full turns of tension until the band is completely relaxed. The next time you use our bands, add the same amount of turns of tension that were taken off. At this point, you will only have to run the flutter test one time.
HTH,

Glenn
 
I have the G0555 (not 'X' model) and have never conquered the 'flutter' business either. I just keep tightening until it feels tight enough to me. Seems to work. I release tension. (when I remember to :rolleyes: )
 
Just to stir the pot....

The bandsaw blade manufacturers know how much tension is required to keep their blade cutting properly. They give that figure in terms of pounds of strain. Knowing what the strain number is, you can calculate how much "stretch" you need to have in your blade when it is properly tensioned. There is a constant, known as "Young's modulus of elasticity" (IIRC) which gives the factor that needs to be applied when calculating the stretch (I can't find it right now or I'd post it) for any material, such as steel. This is how I calculated the tension that I needed to apply to my sawmill bands (bandsaw on steroids - same basic idea). Once I have calculated how much stretch I needed I clamped a dial vernier to the blade and tensioned it until it stretched the correct amount. I recorded where I was for tension and simply go back to the point every time I tighten up the saw bands to use them.

Here's a couple of links :

http://www.taunton.com/finewoodworking/pages/w00013.asp

http://www.sawmillcreek.org/showthread.php?t=22144

http://www.forestryforum.com/board/index.php/topic,10765.0.html

http://www.forestryforum.com/board/index.php/topic,7923.0.html

cheers eh?

John
 
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