Bandsaw blade fishtailing

I was ripping some 1 1/4" thick hardwood (from a pallet--oak and elm, I think) on the bandsaw and noticed the blade doing something odd. Instead of cutting straight like it usually does, the blade still maintained a straight-ish line but seemed to fishtail through that section. The blade would wobble back and forth through that section. Increasing the feed rate seemed to help a little, but it would go away on its own.
The guides were a little high, about 1 1/2" above the wood (I had cut taller pieces just before that and didn't want to adjust the guide, make sure the blocks were set etc) but I wouldn't think that would be tall enough to make a difference.
I'm using a 1/2" woodslicer blade.
Why would the blade start to fishtail in some piece of wood? Is it a sign of too little tension, the blade dulling, or just something inherent in the wood?
Puckdropper
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Hard to tell by that description. the wobble sounds like multiple possibilities. Are the guides close the the blade, or too far out. Is the bearing in the back in contact with the blade? It shouldn't be until you cut. And your guides should be right behind the gullets. if the bearing in the back is pushing on the blade before contact it will make the blade wander, and if the guides are too far back the same.
Check the lower guides too for the same ... The wood slicer and timberwolf blades are not high tension blades. They require bringing the blade to a little past flutter. I go a little further than called for but still lower tension than olsons...
1.5 " is not too high above, so I am discounting that.
Sorry, the reason can be many... but those are good starting points. And the basics.
On 11/2/2011 10:05 PM, Puckdropper wrote:

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tiredofspam <nospam.nospam.com> wrote in

The bearing behind the blade does not move until the wood contacts the blade. Guides (both upper and lower) are close to the blade, but do not touch it.
Puckdropper
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"Puckdropper" <puckdropper(at)yahoo(dot)com> wrote in message

This isn't much help if you don't have one but when my band saw starts taking a new path when cutting too thick or dense stock I move to the table saw for ripping.
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The first thing I'd suspect would be the set of the blade teeth. You are cutting through growth rings as you go, and some parts (winter wood vs. summer wood) are softer and some are harder. If the set edges of the teeth have lost sharpness, the harder parts of the growth rings may push the blade slightly one way until the blade moves far enough to sort-of snap back, cutting into that hard part. The blade could still feel sharp on the top surface of the teeth and still do this. If I have this problem, I change to a brand new blade to see it it makes a difference.
Pete Stanaitis ---------------
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