Thread: bandsaw cutting funny

Stop cutting up clowns and all should return to normal!!! But seriously, is the tension correct for the blade. Sounds to me that it may be a little loose.. I'm sure others will wade in shortly.
Cheers

Tension is right as far as i can tell - 100 year old machine so it doesnt have a tension meter or anything fancy like that

Has the blade developed a twist in part of its length while cutting curves?

the blade does twist slightly when cutting curves, but when the wobble starts it continues even after the curve is finished

Tooth set on each side of the blade may have deteriorated unequally, from cutting curves in a favored direction. Resonance could make it worse. Ideally, this can be reduced by alternating direction of curved cuts, and using the same speed of feed in each case.

You should be able to sense tooth set variations by GENTLY gripping the blade with finger and thumb, and SLOWLY moving the blade upwards, WITH THE POWER OFF. If you find such variations, professional sharpening and setting may be able to correct it.

A new blade should also be considered. Eventually, you'll need one anyway.

Cheers,
Joe

Hmm, I'm wondering whether the problem is a bit more serious. ie bearings/bushings for the drive wheels may be on the fritz. It fits the symptoms.

I'm wondering if part of the blade has developed a permanent twist. That, or as Joe says, uneven wear, are the first things to check. It could be the bearings, but check the simplest things first.

Thanks for all the repiles.

Just to clear something up, it's not specific to the blade (they have all done it) but our other bandsaw doesnt have the same problem.

both machines are the same vintage (about 100 years old) and have had the old wooden bearings changed to sealed ball bearings many years ago.

The one difference is that the wobbling saw has new Carba-Tec Industrial ceramic blade guides (which, btw, are absolute crap and are probably the WORST way to spend $100) and the non-wobbling saw has the original guide which covers a much larger section of the blade.

The one thing that still baffles be is the fact that the ripples are evenly spaced at about 6mm apart REGARDLESS OF FEED RATE

Post photo sounds? Like you have a badly set tooth or teeth or problems with temper or tooth shape ,tension .

Hi Elanjacobs,
A most likely silly Question, but I take it you are not using the height adjustment, right to the top & it really should be just above the thickness if the wood.
I also thick there is trouble with the Blade.
You haven't told us the size of the Saw or the Blade width & TPI. These could be important as well, but it does sound like the Blade is not quite tight enough.
Regards,
issatree.

I do set the height to about 5mm from the timber.

The blade is 1/2" 4TPI, case hardened, skip tooth.

Not sure of the exact size of the wheels but i think they're around the 30" mark.

As mentioned before, we have 2 identical bandsaws both running the same blades. One of them is fine and the other has the same wobble problem with breand new blades as with used blades.

The worst bit is that sometimes it cuts fine and sometimes it wobbles both with new and old blades