Band Saw Tune-Up & Resawing Secrets
9/26/2005
Provided by American Furniture Design
Co.
The band saw is a versatile tool that many woodworkers find to be as
indispensable as the table saw. It is essential for cutting curves, roughing out
turning blanks and re-sawing veneers. The saw gets its name from its narrow
steel blade and they range in size from 1/8” to over 1 1/2” in many larger saws.
In this article, we will cover how to tune it up so that it runs trouble free
and how to re-saw material. For a woodworker, few things are more satisfying
than re-sawing thin sheets of veneer out of a large piece of wood or slicing a
great board in half to create two book matched pieces. But to do this the saw
must be tuned correctly or the re-saw process will be a disaster. Here are four
simple adjustments that will keep your saw cutting true. It’s a good idea to
check these adjustments each time you use the saw. You’ll need to check them
whenever you change the blade.
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Tension the blade.
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Track the blade.
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Square the blade.
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Adjust the guides.
Tensioning the Blade.
When you install the band saw blade, the first thing to do is put tension on
it to hold it on the wheels. Many saws have a gauge that tells how much tension
to put on the blade based on its width. In addition, we suggest that you tighten
the blade and then pluck it like a guitar string. The blade should produce a
clear tone, rather than a dull thud. Next check the blade for deflection. Raise
the guide all the way up and then push sideways on the blade. It should not
deflect more that 1/4” to 3/8”. The narrow blades will deflect more than wide
ones. Some folks recommend that you over tension the blade to correct the saws
cutting problems. While it is true that the blades and the saws can stand more
tension that the gauges suggest, it is not a good idea to put too much tension
on the blades. It can cause the saw’s bearings to fail prematurely. If the saw
sits for a long time without use, it can cause flat spots on the tires, which
will cause vibration and erratic cuts.
Tracking the Blade.
When your saw is tracking correctly, the blade runs on the middle of the
wheels. Adjust the tracking by tilting the top wheel in relation to the bottom
wheels. A knob behind the upper wheel housing controls this adjustment. Spin the
saw by hand and adjust the tracking control until the blade is running in the
middle of the wheel. Lock the control in this position. Replace the cover and
plug in the saw. Check the tracking by bumping the switch on and off. The blade
should maintain its position. Repeat this several times before running the saw
at full speed.
Square the Blade & Table.
This adjustment is often the forgotten one and can cause nothing but
problems. It is a very simple adjustment. Loosen the knobs that lock the table
in place. Hold a small square on the table with its blade against the saw blade.
Square the table to the blade and lock it in place. Under the table, there is
usually a stop that you set to automatically square the table after you’ve had
it tilted.
Setting the Guides.
Most band saws have two similar sets of guides, one set above the table and
the other below. There are two different types of these, one has a rear guide
bearing and then two guide blocks. The second has the rear bearing and also two
side bearings. The back bearing resists the force that you apply as you push the
board past the blade, while the guide blocks or bearings prevent the blade from
twisting out of position. Both sets can be adjusted the same way..
Move the guard up about halfway between the table and the top of the case.
Depending on how accurately the guard moves up and down you may have to set the
guides to allow it to move. Set the rear bearings first, both top and the
bottom. Move them forward until they almost touch the blade. Leave about 1/32”
gap between the blade and the bearing. We have found that a dollar bill works
just fine. Then set the guide blocks or the side bearings using the dollar bill.
When all are in place lock them. Your saw should now be ready to run! If you
have problems with the way it is cutting after this tune-up, the saw may require
more involved adjustment. There may be a problem with the alignment of the
wheels with one another, balancing the wheels and adjusting the drive train.
This is time for the owner’s manual to assist with these problems.
QUICK TIPS!
Clean tires!
One-way to prolong the life of the band saw tires is to keep them clean. To
install a continuous cleaning system use an old toothbrush. Cut the handle short
and heat it to bend to the right shape at 90 degrees. Drill holes through the
shortened handle to bolt the brush in place inside your saw on the bottom wheel
of the saw.
Fine-tune the Blade!
Round the rear edges of your band saw blades with a medium-grit oils stone.
You’ll find that relieving these edges will allow you to cut tighter curves and
will make backing out of cuts much easier. Hold the stone flat on the saw table
and gently touch it to the back of the blade as it is running.
Resawing Secrets
Almost all problems that occur with resawing after you have tuned up your saw
is due to the wrong blade being used. A dull blade is nothing but trouble! You
should use the widest blade that your saw can handle. Select a blade with three
or four teeth per inch and a 5 to 10 degree hook. The hook tooth design is an
aggressive blade that has deeper gullets for better sawdust removal and it also
reduces the feed pressure that you have to make. You will find that most 3/4”
blades are .025 in thickness which is too heavy for a 14” bandsaw, so use a 1/2”
blade.
If you are very fortunate, your band saw will track perfectly and resawing
will be a great experience, but if are like 99% of us it will not. The fence is
the first thing that needs modification. The fence needs to be as high as the
piece being sawn. If the fence is too low, when feeding the board through the
saw the bottom of the board will tend to move away from the fence. The face of
the fence MUST be 90-degrees to the table. Even if the fence is out of square by
only a 1/2-degree, the finished boards resawn from a wide board will have a
taper.
You may have to adjust the fence for lead or drift. Setting the fence at the
right drift angle is critical to resawing. Start by cutting on a piece of scrap.
Stop about half the length of the board and trace the angle of the board onto
the bandsaw table with a pencil line. Clamp the board to the table and set up
the fence along the joined edge of the board. Now the fence is parallel to the
cut, and the blade will have no drift. Be sure to join both edges and one face.
Run the joined face against the fence.
When you re-saw keep both hands on the piece. Put our right hand on the end
grain, pushing the board through the saw. Keep the left hand low and spread your
fingers to press the piece against the fence across a wide area. Slow constant
feed pressure is the key to success. If you stop sawing for a moment, the blade
will bite a bit deeper.