Blade tension on bandsaw

[Wilson joinery]

Hi everyone, could anyone shed some light on how tight a blade should be on a bandsaw? I’ve got a little inca euro 260 which is tremendous but I’m struggling to work out if I’ve got the blade at the right tension. It cuts well but if I put a small amount of sideways pressure onto the blade it deflects by a few mm. Or if it’s cutting ok should I not worry about the tension too much? Cheers Pete

 

[Spectric]

First the tension gauges on many bandsaws are not accurate, the supplied blades are no good and also the manufacturers may say this machine can run this size blade but unless it can be tensioned correctly it will not perform, my BS400 is supposed to take a 1 inch blade but I find 3/4 is really it's limit.

The actual tension is hard to describe and there are a few methods including the flutter method, I would take a look at Mr Snodgrasses video on bandsaws as it may shed some light.

 

[deema]

The only way is to use a blade tension meter, bought or the home made flavour. You also need to check the tension spring isn’t compressed by more than 25% of its natural length. To do so, destroys them and you will need another.
Flutter methods, vibration detectors on your phone don’t work. Sideways and I have tried a few.
@Spectric is right, most saws cannot tension up the maximum specified width, and that’s just HSS blades!

 

[Sideways]

Your Inca is a sweet little saw, cast alloy frame. Very good motor for the size of saw.
If it is working for you, don't worry about it.
If you are interested in the technicalities there are useful things to learn from this thread
https://www.ukworkshop.co.uk/threads/scm-minimax-s45-bandsaw-teardown-overhaul.135069/and a one about blade guides posted by "deema" a few months ago.

My advice is :
High blade tension plus accurate tracking are the keys to good bandsaw performance.
Blade guides are irrelevant to a well setup bandsaw used within it's limits.
A good blade is important. Tuffsaws premium are a sound choice. Don't waste time on M42 blades on a small saw. Better a quality, sharp, carbon blade and the correct teeth per inch is very important. Tell us what you want to cut...
You have a small saw. It will not have the strength to tighten a wide blade properly. Better a narrow blade properly tight than a wide one that is inadequately tensioned. Guessing, not more than 1/2" 12mm on your saw.

 

[Chris Hawkins]

Comments above are spot on. I use the deflection method. It's funny when I first got my Sabre 350 I used to fret about all sorts of things and now I can’t see why. Now I just use it - 95% for resawing and it seems to tolerate quite a broad range of tensions without effecting the cut. I used to use 5/8 blades, but have now switched to 1/2inch And can’t see myself using anything else in future - cheaper, easier to tension.

 

[luckyman.com.da]

Hi everyone, could anyone shed some light on how tight a blade should be on a bandsaw? I’ve got a little inca euro 260 which is tremendous but I’m struggling to work out if I’ve got the blade at the right tension. It cuts well but if I put a small amount of sideways pressure onto the blade it deflects by a few mm. Or if it’s cutting ok should I not worry about the tension too much? Cheers Pete

Hi Pete,
The general rule of bandsaw blade fitting is keeping it central to the wheel - tension it until the blade cant slip - balance the to & fro - side preasure should not be used incase the blade snaps. If the blade is still running out or forcing you to put side preasure on - check the set & sharpeness, emphasis on equal tooth set.
Good luck

 

[Wilson joinery]

Thanks for all of the really useful info everyone, great knowledge as always!

 

[Jameshow]

The max tension is just before it snaps with a bang and you jump across the workshop and hug the table saw!!

 

[baldkev]

The max tension is just before it snaps with a bang and you jump across the workshop and hug the table saw!!

Hopefully with the tablesaw blade stationary

 

[Ttrees]

The max tension is just before it snaps with a bang and you jump across the workshop and hug the table saw!!

I've never had a blade snap, but have I read of many accounts of this.
Seems little information regarding folks actually describing their blade snapping in detail, but from what little I can gather, it seems like the snapped blade will try and exit the machine, in a linear fashion,
i.e in-line with the wheels and exit between the guides.

I wonder if I'm correct about thinking this is the likelyhood, should the blade not catch on the tires and gouge or cut them off.

This photo might suggest so

I wonder if these photos of a Canadian Luthier's Grant Goltz setup would be for the same reason,
or if it was just because of the huge billets.
A video exists somewhere I might try find.

Worth noting most of the Italian machines have fences which can be used either side.

 

[pulleyt]

I have had a couple of bandsaw blades snap. The noise made me jump each time, but the drive to the blade was immediately removed as the blade was no longer tensioned around the drive wheel and the blade just hung in place in the guides. I wasn't quite ready to hug the table saw

EDIT: I have a Kity bandsaw where the blade teeth are not touching the wheels and therefore unlike to catch the wheel rubber. Bandsaw where the blade is centred on the wheel may behave differently.

 

[John Brown]

Hi Pete,
The general rule of bandsaw blade fitting is keeping it central to the wheel - tension it until the blade cant slip - balance the to & fro - side preasure should not be used incase the blade snaps. If the blade is still running out or forcing you to put side preasure on - check the set & sharpeness, emphasis on equal tooth set.
Good luck

On the Inca, the blade is not centred, as the wheels have no crown. The teeth are supposed to just hang over the edge of the tyre.

 

[baldkev]

Ive had one go bang, like pulleyt, mine immediately lost drive and ground to a halt