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TROUBLESHOOTING
ARTICULATING THE HOOK AND SET OF TIMBER WOLF® BAND MILL BLADES
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BLADE RIDES UP IN THE CUT IN THE FIRST SIX
INCHES AND STAYS THERE - it cuts straight until the end and then drops down.
This is called "push-off." You have too much hook angle. Decrease
the hook angle by 2 degrees. See
“HOOK ARTICULATION”
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BLADE RIDES UP IN THE CUT - plus when you
pull the board off you have a bow in the board. This is caused by too much
hook angle and not enough set. Reduce the hook angle by 2 degrees and
increase the set by .003” per side.
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BLADE DROPS DOWN IN THE CUT AND STAYS THERE -
This could be caused by a dull blade but usually means you have too little
hook angle. Increase the hook angle by 2 degrees.
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BLADE DROPS DOWN IN THE CUT - plus when you
pull the board off, you have a bow in the board. This is caused by too
little hook angle and not enough set. Increase the hook angle by 2 degrees
and increase the set by .003” per side.
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EXCESSIVE LOOSE SAWDUST ON THE BOARD AND LOG
- This is caused by too much set, and if you look closely, you will probably
see some tooth marks. Down-set about .003” per side.
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EXCESSIVE PACKED SAWDUST ON THE BOARD AND LOG
- This is caused by too little set. Up-set about .003” per side. You could
also be highly overset causing the body of the blade to bounce in the cut.
This is always accompanied by deep tooth marks. If so, down-set by .006”
per side.
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PACKED SAWDUST IN FROZEN LOGS – Down-set to
.017” per side but no lower than .015” This will pinch down on the blade
and force the sawdust out of the cut before it freezes. Also use 8-degree
hook angle in frozen logs. Blades should only be run about half as long when
cutting frozen logs.
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BLADE CUTS IN A WAVY MOTION – The blade is
EXTREMELY under-set. For a small wave, up-set the blade .004” per side.
For a heavy wave, up-set .006”. Running a blade that is under-set is the
MOST damaging thing you can do to the steel.
See
“APPROPRIATE SET”
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BLADES ARE CRACKING FROM THE BACK OF THE
BLADE - this is caused by bad guide bearings and/or bad guide alignment. The
most common cause is the back guide bearing(s) or flange(s) is set too far
back or set too close to the blade. Never run the blade without some
clearance at the back edge, but never exceed more than .125” clearance to
the bearing or flange.
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NEW BLADES THAT HAVE NEVER BEEN SHARPENED ARE
CRACKING IN THE GULLET - This is usually caused by a blade being run to
extreme dullness or by running a heavily under-set blade. Excessive S.F.P.M,
excessive tension and/or a bad wheel bearing can also cause this.
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EXCESSIVE PITCH BUILT UP ON THE BODY OF THE
BLADE - even when you are using our lubrication advice. The set is too low,
leaving no air space. The blade body is rubbing on the wood producing
excessive heat and pitch build up. Up-set the blade .004” per side.
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PITCH BUILT UP IN THE GULLET OF THE BLADE -
but no pitch built up on the body. This is usually caused by improper
sharpening, too much hook angle or just a dull blade.
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AFTER A FEW SHARPENINGS THE BLADES CRACK IN
THE GULLET – Low Hook Angles! Any blade that is sharpened to less than 8
degrees will break. Buy a protractor!!!! You can’t sharpen properly
without it. Also, if you sharpen the gullet so that it is squared off you
will produce excessive heat and stress at the bottom of the gullet, which
ruins the temper of the steel. Lastly, if you run your blades too long they
will break. Even if a blade is set and sharpened perfectly it should only be
run for a maximum of 3 hours.
THE
CAUSE: improper set and/or inaccurate set are the cause of most blade
problems. Also, improperly dressing the stone and/or not dressing the stone
often enough are the cause of many blade problems. Dress your grinding stone
lightly after every pass. When your blades are set and sharpened properly you
should produce straight boards at a good feed rate and see 85% of the sawdust
ejected from the cut.
IMPORTANT
NOTE: If you had to gauge the importance of setting the teeth versus
sharpening them, remember this; a blade that does not have the sharpest edge
will still cut straight if the teeth are set accurately, whereas a blade that is
super sharp but has inaccurate set will not cut at all.
HOW LONG SHOULD YOU RUN A BAND MILL BLADE?
When
a TimberWolf blade is new or has been properly sharpened there is about 5 pounds
of pressure per square inch applied to the face of each tooth. Friction, impact
and heat will dull the teeth during use. As the edge and tip of the tooth erode,
the pressure on the face of each tooth increases dramatically. If this pressure
exceeds 15 pounds per square inch, the gullets of the teeth will start to
stretch and will be literally ripped apart over time. If the blade is run to
this same point of dullness each time, the steel will fail and you will lose 50
to 75% of the life of the blade. That equates to 2 or 3 sharpenings as opposed
to 8 or 10 sharpenings over the life of the blade.
So how long
should you run a blade?
Always change your blade while it is still
relatively sharp.
Run the blade for 2 to 3 hours max!
Also, if your
blades are set or sharpened improperly you might start with 15 pounds of
pressure. These blades are being ripped apart from the moment they are put on
the mill.
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IF YOU HAVE ANY QUESTIONS OR NEED TECHNICAL ASSISTANCE
DO NOT HESITATE TO CALL
1-800-234-7297
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TEST: CAN YOU SOLVE THIS?
You are going to cut 16" to 26" green
knotty pine. You know when you hit the knots, the blade goes crazy. How would
you articulate the blade for this job?
ANSWER:
Take the model #100 SS, which is pre-set
at .028 to .029 thousandths per side. Push your set out to .035 thousandths,
set your gullet procedure sharpener to 8 degrees. Kiss sharpen the band twice.
What you now have is our Timber Wolf again set at .031 to .032 thousandths.
You have produced a perpendicular or square tooth tip and you have increased
you penetration factor to take on the very hard knots, by reducing the hook
angle. Upon using this articulated band, you will find your feed rate
increased. You will have no aggressive behavior and best of all, those darn
knots don't seem to be there any more.
THE SAW DOCTOR
RULE 1--Use appropriate set for pre-determined
over all chip expansion.
RULE 2--Articulate the hook angle for the toughest part of the cut.
THE SAWYER
You must sooner or later REALIZE you cannot take
any mill, throw any band saw blade on it and expect everything to go smoothly.
EXAMPLE: The portable band mill owner must SEGREGATE his logs at 18" and
also continue to SEGREGATE the soft wood from hard wood. Then ARTICULATE the
band saw blade for what you will be cutting.
We can GUARANTEE this, with your mill, and our
bands. Some bands will be as they come and some will be articulated, segregate
the logs and start cutting. Also use our lubrication example. You will produce
23% to 36% more lumber and profit a day. We have already proved it and better
than that, we have helped sawyers over and over, exceed this.
RECOMMENDED APPROPRIATE SETS AND HOOK ANGLES
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1 1/4" x 3/4"
Bands Only
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Soft Wood
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Soft Wood
Very
Knotty
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Medium
Hard
Wood
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Hard
Wood
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Very
Hard or
Frozen*
Wood,
Old Barn
Beams
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Recommended Hook
Angle
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10°
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8°
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10°
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10°
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8°
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Thickness of Cut
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Set Per Side
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Set Per Side
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0" through 6"
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.021 use model 86SS
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.019 use model 80SS
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7" through 12"
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.024 use model 90SS
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.021 use model 86SS
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13" through 22"
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.029 use model 100SS
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.024 use model 90SS
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23" through 30"
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.034 up set 100SS
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.029 use model 100SS
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31" and higher
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.038 up set 100SS
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.034 up set 100SS
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1 1/4" and
1 1/2" x 7/8"
Bands Only
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Soft Wood
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Soft Wood
Very
Knotty
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Medium
Hard
Wood
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Hard
Wood
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Very
Hard or
Frozen*
Wood,
Old Barn
Beams
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Recommended Hook
Angle
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10°
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8°
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10°
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10°
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8°
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Thickness of Cut
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Set Per Side
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Set Per Side
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0" through 6"
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.019 use model 80SS
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.017 down set 80SS
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7" through 12"
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.021 use model 86SS
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.019 use model 80SS
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13" through 22"
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.024 use model 90SS
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.021 use model 86SS
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23" through 30"
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.027 up set model 90SS
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.024 use model 90SS
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31" and higher
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.031 up set model 90SS
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.027 up set model 90SS
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1 ˝" & 2" x 1"
Bands Only
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Soft Wood
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Soft Wood
Very
Knotty
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Medium
Hard
Wood
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Hard
Wood
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Very
Hard or
Frozen*
Wood,
Old Barn
Beams
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Recommended Hook
Angle
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10°
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8°
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10°
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10°
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8°
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Thickness of Cut
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Set Per Side
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Set Per Side
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6" through 12"
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.019 use model 80SS
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.017 down set 80SS
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13" through 22"
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.021 use model 86SS
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.019 use model 80SS
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23" through 30"
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.024 use model 90SS
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.021 use model 86SS
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31" and higher
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.027 up set 90SS
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.024 use model 90SS
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*Note: Some species, when frozen, will
require set as low as .015
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