Bandsaw Blade Tension

Lodgepole · Post by **Lodgepole** » Mon Mar 09, 2009 7:28 pm

I emailed Shopsmith Staff and asked them if the tension on the bandsaw blade should be released when not in use. They informed that indeed it should be.

I have looked at their new bandsaw cover, which has a hole for the Allen wrench and a window to view the tension scale. After checking the catalog, it appears that quantities may be limited.

In case they run out of this product, has anyone else modified their existing cover to include these 2 improvements?

If not, how do you handle releasing the blade tension? Do you completely remove the blade after each use?

I noticed from photos, one of our forum users uses masking tape on the side of his bandsaw with a "Tension Off" as a reminder.

Thanks in advance for any advice you might have.

charlese · Post by **charlese** » Mon Mar 09, 2009 8:29 pm

lodgepole wrote:...I noticed from photos, one of our forum users uses masking tape on the side of his bandsaw with a "Tension Off" as a reminder.

Thanks in advance for any advice you might have.

Yes, I put the tape on, it's been there for about a year now. Time to renew the tape and try to print better. Didn't realize, at the time, I would be showing photos of the tape!

I had given thought to cutting a allen key hole and a window hole. Some "Forum Folks" have. I've also given thought to ordering one of the new covers, but thought, "what would I be saving?" It is only the time to remove the three knobs! So... put on the tape.

The tape is a reminder to loosen as well as tension the blade. After a day's use, I remove the cover (gives me a chance to look at the innards and clean up if needed) and loosen the tension until the top wheel drops down enough to allow the blade to bulge out on the left. Also the tension bar is just outside the 1/8" mark. I leave the blade on until a blade change is needed.

8iowa · Post by **8iowa** » Mon Mar 09, 2009 8:40 pm

Last year when I purchased a Shopsmith from a local widow, the package included a bandsaw. The previous owner had used a hole saw to cut through the cover and then screwed a small plate of clear plastic inside to cover the hole. A simple modification, but it works.

I do not totally loosen the belt, but rather turn the 5/32" wrench about 1 1/2 turns. If you loosen it too much then you might have to take off the cover and re-set the blade on the wheels.

Gene Howe · Post by **Gene Howe** » Mon Mar 09, 2009 8:41 pm

I drilled a small hole at the back (left side as you face the saw) for the hex wrench. Then another hole (2.5") in the cover so that the tension gauge was visible. Some have glued a plexiglass window behind the hole. I didn't bother.

JPG · Post by **JPG** » Tue Mar 10, 2009 12:30 am

Anybody care to tell us all WHY this is necessary?

charlese · Post by **charlese** » Tue Mar 10, 2009 2:24 am

JPG40504 wrote:Anybody care to tell us all WHY this is necessary?

My take (probably a bit sarcastic and maybe curmudgeon like) is it's cool!

Saves one from the dastardly chore of removing three knobs and removing the cover. Also it is an inexpensive alternative of purchasing a new revised cover. And the owner gets the added satisfaction of making this modification his/her self.

The down side is you will not look inside of your saw as often and may miss something that has gone wrong, or needs lubrication.

Really, since I seldom use the same blade for more than one or two operations, the modification would save me little effort. 5/8" skip tooth for re-sawing, 1/4" for most curves and 1/8" for tighter turns.

JPG · Post by **JPG** » Tue Mar 10, 2009 3:03 am

charlese wrote:My take (probably a bit sarcastic and maybe curmudgeon like) is it's cool! Saves one from the dastardly chore of removing three knobs and removing the cover. Also it is an inexpensive alternative of purchasing a new revised cover. And the owner gets the added satisfaction of making this modification his/her self.

The down side is you will not look inside of your saw as often and may miss something that has gone wrong, or needs lubrication.

Really, since I seldom use the same blade for more than one or two operations, the modification would save me little effort. 5/8" skip tooth for re-sawing, 1/4" for most curves and 1/8" for tighter turns.

The "THIS" I was referring to was the action of 'releasing the tension', NOT the holes/windows etc. I understand why one would want an easier way to release it(or normal adjusting), but I do NOT know why it needs releasing, hence the original question.

- Aren't pronouns wonderful?!

dusty · Post by **dusty** » Tue Mar 10, 2009 6:54 am

JPG40504 wrote:Anybody care to tell us all WHY this is necessary?

Sorta like brushing your teeth - it isn't necessary, just well advised that you do!

billmayo · Post by **billmayo** » Tue Mar 10, 2009 7:06 am

JPG40504 wrote:The "THIS" I was referring to was the action of 'releasing the tension', NOT the holes/windows etc. I understand why one would want an easier way to release it(or normal adjusting), but I do NOT know why it needs releasing, hence the original question. - Aren't pronouns wonderful?!

I see many bandsaws that the tension has not been released for long periods of time. The bandsaw blade will imprint itself into the tire so you have 2/3 of the tire with this imprint and 1/3 being smooth. This creates vibration, flexing of the blade as it goes around the tire and the upper arm/axle and blade tensioning assembly to be moving all the time. This causes stress in the upper arm/axle which allow the upper wheel to tilt out at the top over time. Then the bandsaw blade comes off the upper wheel when power is applied. I normally have to replace the bandsaw tires and straighten the upper wheel, arm and axle for the proper tilt.

dusty · Post by **dusty** » Tue Mar 10, 2009 10:35 am

billmayo wrote:I see many bandsaws that the tension has not been released for long periods of time. The bandsaw blade will imprint itself into the tire so you have 2/3 of the tire with this imprint and 1/3 being smooth. This creates vibration, flexing of the blade as it goes around the tire and the upper arm/axle and blade tensioning assembly to be moving all the time. This causes stress in the upper arm/axle which allow the upper wheel to tilt out at the top over time. Then the bandsaw blade comes off the upper wheel when power is applied. I normally have to replace the bandsaw tires and straighten the upper wheel, arm and axle for the proper tilt.

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