Thread: Snapping Blades

Check to see how close the guide blocks are to the blade. You may need to bring them up to touch the blade to stop twist. You may be trying to feed the wood to quickly and putting pressure on the blade before it has time to clear of sawdust. You may also have too fine a blade for the thickness of the wood. Some woods cut more easily than others so you will have to make allowances for various wood species.

A recent Fine Woodworking mag (Power Tool Basics 2007) suggests the following setup for bandsaws...

A half-inch, 3 tpi blade, with less than the recommended tension (a deflection of 1/4 inch to the side without your fingertip going white!)

Make sure that the blade weld area is nice and smooth so it's not going to catch (sandpaper it if its not smooth).

The blade guide blocks should be aligned so that the front of the block is just behind the gullet of the saw blade, and they should clear the side of the blade by only about 0.001 of an inch to each side (regular photocopier paper is about 0.003 of an inch thick, so you need tighter clearance than that! The article mentions that cigarette paper is about 0.001 thick, but so is the carbonless paper that many invoice books use so have a dig in your wallet for a suitable one!)

The bearing behind the blade should only be about 1/32 of an inch away from the back of the blade.

See if that helps!

BTW - don't throw away the snapped blades!

Send them to Henry Bros - he is happy to reweld them - can't remember how much he charges, but it is much cheaper than a new blade. Have a few, and when you get low, send off the broken ones.

Regular guides aren't appropriate for a 1/8-in blade, because not enough contact area. Such blades are sometimes packaged with substitute guide blocks of high-strength plastic; DIY hardwood blocks are also used: let the blade do the final shaping.

Joe

1/8th blade, sure your not putting to much tension on it?

Stuart. i have a special place in my shop for snapped BS blades. i wil be taking the to Henry Bros as soon as i have a decent stockpile (which wont be long the way im going...)

i think my problem is tension. i did some cutting last night and i backed off the tension a little and the blade lasted longer than previously. i also adjusted the bearing guides to make contact with the blade (to provide more support).

the other thing i just realised is that i dont need a 1/8 inch blade to make most of the cuts i have been making!!! and since switching blades is pretty simple to do i will be selecting the right blade for the job from now on...

Hi gabacus,
I see, you are playing and learning. BTW I now back off the tension when finished so I don't distort the tyres and load bearing and wheels up too much...specialy now with cooler weather.

Cheers,
conwood

When I was at Henry Bros, a customer came in who'd just bought a 10" bandsaw.

The advice he got was to return it, scrap it, or give it away, on account of it was going to be snapping blades so fast it would be cheaper to buy a bigger saw that didn't snap blades.

Apparently the small wheel diameter requires blades thin and flexible enough to curve around the small radius, and the tight flexing of thin blade means more frequent snapping.

The larger saws have larger radius wheels, which means less flexing of the blade, which means the blades can be thicker and thus stronger.

Cheers,
Andrew

Originally Posted by arose62

When I was at Henry Bros, a customer came in who'd just bought a 10" bandsaw.

The advice he got was to return it, scrap it, or give it away, on account of it was going to be snapping blades so fast it would be cheaper to buy a bigger saw that didn't snap blades.

Apparently the small wheel diameter requires blades thin and flexible enough to curve around the small radius, and the tight flexing of thin blade means more frequent snapping.

The larger saws have larger radius wheels, which means less flexing of the blade, which means the blades can be thicker and thus stronger.

Cheers,
Andrew

hey andrew,

when i spoke to the guys at Henry Bros about buying some blades i got the same impression. they didnt outright say it but they did say that due to the small wheels i would need blades made out of special material so they dont snap so often.

unfortunately, a 10" is all i can afford at the moment. i will be upgrading first chance i get but for now i will have to make do. i must say it is a frustrating situation because other than the snapping blades the BS has been doing a great job. i have had so much fun with it, and at the end of the day thats what its all about.

cheers