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

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:
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

tiredofspam nospam.nospam.com wrote in
:

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.


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

"Puckdropper" puckdropper(at)yahoo(dot)com wrote in message
b.com...
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

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.

On 03 Nov 2011 02:05:47 GMT, Puckdropper
puckdropper(at)yahoo(dot)com wrote:

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?

Too little tension or too -hard- a feed rate are the usual culprits.
That's some hard wood, so give it time to cut. Also, you might have
too many teeth per inch when ripping and could be clogging teeth.

If your guides are set correctly, it should help.

--
Knowledge speaks, but wisdom listens.
-- Jimi Hendrix

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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