C.Cutting off a cantilevered overhanging piece of material from the bottom in a vertical direction. The falling
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
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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