C. Cutting off a cantilevered overhanging piece
of material from the bottom in a vertical
direction. The falling cut-off piece can pinch
the blade.
D. Cutting off long narrow strips (as in
ripping). The cut off strip can sag or twist
closing the kerf and pinching the blade.
E. Snagging the lower guard on a surface
below the material being cut can
momentarily reduce operator control.
The saw can lift partially out of the cut
increasing the chance of blade twist.
Improper Depth of Cut Setting on the Saw
Using the saw with an excessive depth of cut
setting increases loading on the unit and sus-
ceptibility to twisting of the blade in the kerf.
It also increases the surface area of the blade
available for pinching under conditions of kerf
close down.
Blade Twisting
(Misalignment in Cut)
A. Pushing harder to cut through a knot, a nail
or a hard grain area can cause the blade to
twist.
B. Trying to turn the saw in the cut (trying to
get back on the marked line) can cause
blade twist.
C. Extended reach or operating saw with poor
control (operator off balance), can result in
twisting the blade.
D. Changing hand grip or body position while
cutting can result in blade twist.
E. Backing unit up to clear blade can lead to
twist if not done carefully.
Materials that Require Extra Attention
A. Wet timber.
B. Green timber (material freshly cut or not kiln
dried).
C. Pressure treated timber (material treated
with preservatives or anti-rot chemicals).
Use of Dull or Dirty Blades
Dull blades cause increased loading of the
saw. To compensate, an operator will usually
push harder which further loads the unit and
promotes the twisting of the blade in the kerf.
Worn blades may also have insufficient body
clearance which increases the chance of
binding and increased loading.
To minimise the splintering:
Do not force the saw.
Cut from the opposite side if possible.
Clamp a thin piece of scrap over the top of the
material to be cut. Cut through both the scrap
and the original work piece.
Do not overload the saw. Allow the saw to run
at close to full speed during operation. Do not
force the saw into the work piece. The tool will
cut better when the saw is running at close to
full speed.
In the event where the saw has been used in a
heavy application, or if the saw appears to be
hot, run the saw for two minutes unloaded to
allow the motor to cool. Always ensure the air
intake vents are clear.
Kick Back
When the blade is pinched or bound tightly
by the kerf closing down, the blade stalls
and the motor reaction drives the unit rapidly
backwards towards the operator.
If the blade becomes twisted or misaligned
in the cut, the teeth at the back edge of the
blade can dig into the top surface of the wood
causing the blade to climb out of the kerf and
jump backwards towards the operator.
Using dull blades or improperly supported
work will increase the tendency for kickback.
Wet timber, green timber or pressure treated
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