Bandsaw Blade Tension

JPG · Post by **JPG** » Tue Mar 10, 2009 11:27 am

dusty wrote:When faced with this task, Bill, what is the measure for "proper tilt" of the upper wheel?

I'm guessing 'as far as it will go'.

Thanks Bill!:) Suspected that but thought it too far fetched.

Do the urethane tires have the same(or worse) 'cold flow' problem?

billmayo · Post by **billmayo** » Tue Mar 10, 2009 11:39 am

dusty wrote:When faced with this task, Bill, what is the measure for "proper tilt" of the upper wheel?

Lay a straightedge on the upper wheel. There should be a 1/8" space between the straight-edge and the top edge of the lower wheel. If there is less than the above space, repeat the twisting procedure. If there is more than a 1/8" space, flex the wheel in the opposite direction until the proper space is obtained. If this happens again it can be adjusted again but this is a sign that the arm has become weak. Plan to replace the upper arm soon.

beeg · Post by **beeg** » Tue Mar 10, 2009 11:42 am

It also could be that your top wheel is sloping with the top protruding outward further than the bottom. If the top wheel is aligned correctly, a straight edge layed on the outside edge of the upper wheel should also be about 1/4" outside of the lower wheel. You can fix this by grasping the the top and bottom of the upper wheel and bending it back to this position. If it does not stay in this orientation, you need to buy a new upper wheel arm and axle part (517640). Surprisingly this isn't too expensive. If the arm has been bent quite a few times it gets weak.

FYI, some of my blades do wander about 1/16" away from the upper bearing. I think my saw is properly adjusted.

By the way, what part of the World do you call home? You could enter a general description of the area in your personal profile and it will show each time you post.
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JPG · Post by **JPG** » Tue Mar 10, 2009 11:45 am

billmayo wrote:Lay a straightedge on the upper wheel. There should be a 1/8" space between the straight-edge and the top edge of the lower wheel. If there is less than the above space, repeat the twisting procedure. If there is more than a 1/8" space, flex the wheel in the opposite direction until the proper space is obtained. If this happens again it can be adjusted again but this is a sign that the arm has become weak. Plan to replace the upper arm soon.

Are we 'forming(bending)' it? Seem like constant tension on the arm is another reason to relieve tension! Good Morning Bill!

billmayo · Post by **billmayo** » Tue Mar 10, 2009 12:03 pm

JPG40504 wrote:Are we 'forming(bending)' it? Seem like constant tension on the arm is another reason to relieve tension! Good Morning Bill!

Bending it. Over time, with the constant tension of the blade when not being released, the angle of the axle is reduced by a slight amount. The arm actually twists very slightly and takes a set. This can be corrected by removing the blade, grasping the wheel at the top and bottom and pulling the bottom of the wheel out while pushing the top in toward the frame with LIGHT pressure. This may take several tries until you see the desired results. You can warp or break the upper wheel if you are too strong. I apply a little more pressure each time until the axle actually bends the correct amount.

Lodgepole · Post by **Lodgepole** » Tue Mar 10, 2009 12:09 pm

Thanks to all for the insight!

JPG · Post by **JPG** » Tue Mar 10, 2009 12:37 pm

billmayo wrote:Bending it. Over time, with the constant tension of the blade when not being released, the angle of the axle is reduced by a slight amount. The arm actually twists very slightly and takes a set. This can be corrected by removing the blade, grasping the wheel at the top and bottom and pulling the bottom of the wheel out while pushing the top in toward the frame with LIGHT pressure. This may take several tries until you see the desired results. You can warp or break the upper wheel if you are too strong. I apply a little more pressure each time until the axle actually bends the correct amount.

So you 'sneak upon it'. Care must be taken to not introduce bending force that would cause torsion to the axle about a vertical axis. Apply force at top and bottom of wheel ONLY! Thanks for the band saw education guys!

cityslicker2 · Post by **cityslicker2** » Tue Mar 10, 2009 3:16 pm

I have a bandsaw that was behaving badly (throwing the blade off the upper wheel) and after calling into SS customer service was advised to repair it per Bill Mayo's routine and it worked. I now am in the habit of releasing all tension on the blade after using it. I also modified my cover to allow that to be done without removing the cover - it looks much like what the new covers from SS look like and it took just an hour or so of my time. I used a small section of clear plastic packaging material to cover the window I cut in the cover to view the tension scale. It works very nicely.