DeWalt DCS577 - Kickback Causes and Prevention; Workpiece Support Issues; Depth Setting and Blade Issues; Material and Operational Factors

17
ENGLISH
bound tightly by the kerf closing down, the blade stalls and the
motor reaction drives the unit rapidly back toward 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 back
toward theoperator.
Kickback is more likely to occur when any of the following
conditionsexist.
1. IMPROPER WORKPIECE SUPPORT
a. Sagging or improper lifting of the cut off piece can cause
pinching of the blade and lead to kickback (Fig.Q).
b. Cutting through material supported at the outer ends
only can cause kickback. As the material weakens it sags,
closing down the kerf and pinching theblade.
c. Cutting off a cantilevered or overhanging piece of
material from the bottom up in a vertical direction
can cause kickback. The falling cut off piece can pinch
theblade.
d. Cutting off long narrow strips (as in ripping) can cause
kickback. 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 momentarily reduces operator control.
The saw can lift partially out of the cut increasing the
chance of bladetwist.
2. IMPROPER DEPTH OF CUT SETTING ON SAW
a. To make the most efficient cut, the blade should protrude
only far enough to expose half of a tooth as shown in
FigureE. This allows the foot plate to support the blade
and minimises twisting and pinching in the material. See
the section titled Cutting DepthAdjustment.
3. 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. Over-reaching or operating the saw with poor body
control (out of balance), can result in twisting theblade.
d. Changing hand grip or body position while cutting can
result in bladetwist.
e. Backing up the saw to clear blade can lead totwist.
4. MATERIALS THAT REQUIRE EXTRA ATTENTION
a. Wet lumber
b. Green lumber (material freshly cut or not kiln dried)
c. Pressure treated lumber (material treated with
preservatives or anti-rot chemicals)
5. USE OF DULL OR DIRTY BLADES
a. Dull blades cause increased loading of the saw. To
compensate, an operator will usually push harder which
further loads the unit and promotes twisting of the blade
in the kerf. Worn blades may also have insufficient body
clearance which increases the chance of binding and
increasedloading.
6. LIFTING THE SAW WHEN MAKING BEVEL CUT
a. Bevel cuts require special operator attention to proper
cutting techniques - especially guidance of the saw. Both
blade angle to the foot plate and greater blade surface
in the material increase the chance for binding and
misalignment (twist) tooccur.
7. RESTARTING A CUT WITH THE BLADE TEETH JAMMED
AGAINST THE MATERIAL
a. The saw should be brought up to full operating speed
before starting a cut or restarting a cut after the unit has
been stopped with the blade in the kerf. Failure to do so
can cause stalling andkickback.
Any other conditions which could result in pinching, binding,
twisting, or misalignment of the blade could cause kickback.
Refer to the sections on adjustments and operation for
procedures and techniques that will minimize the occurrence
ofkickback.
Workpiece Support (Fig. O–Q)

WARNING: It is important to support the work properly
and to hold the saw firmly to prevent loss of control which
could cause personal injury. FigureO illustrates proper
hand support of the saw. Maintain a firm grip with both
hands on the saw and position your body and arm to
allow you to resist kickback if itoccurs.
FigureO shows proper sawing position. Note that hands are
kept away from cutting area. To avoid kickback, DO support
board or panel NEAR the cut (Fig.P). DON’T support board or
panel away from the cut (Fig.Q).
Place the work with its “good” side—the one on which
appearance is most important—down. The saw cuts upward,
so any splintering will be on the work face that is up when you
cutit.
Cutting (Fig. O)

WARNING: Never attempt to use this tool by resting it
upside down on a work surface and bringing the material
to the tool. Always securely clamp the workpiece and
bring the tool to the workpiece, securely holding the tool
with two hands as shown in FigureO.
Place the wider portion of the saw foot plate on that part of
the work piece which is solidly supported, not on the section
that will fall off when the cut is made. As examples, FigureO
illustrates the RIGHT way to cut off the end of a board. Always
clamp work. Don’t try to hold short pieces by hand! Remember
to support cantilevered and overhanging material. Use caution
when sawing material frombelow.
Be sure saw is up to full speed before blade contacts material
to be cut. Starting saw with blade against material to be cut
or pushed forward into kerf can result in kickback. Push the
saw forward at a speed which allows the blade to cut without
laboring. Hardness and toughness can vary even in the same
piece of material, and knotty or damp sections can put a heavy
load on the saw. When this happens, push the saw more slowly,
but hard enough to keep working without much decrease
in speed. Forcing the saw can cause rough cuts, inaccuracy,
kickback, and over-heating of the motor. Should your cut begin