DeWalt DCS391 Guide D'utilisation page 19

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. ALWAYS
TURN OFF TOOL AND REMOVE BATTERY BEFORE MAKING ANY
ADJUSTMENTS!
FIG. 10
Figure 10 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. 11). DON'T support board or panel away from the
cut (Fig. 12).
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.
FIG. 11 DO support board or panel NEAR the cut.
SUPPORT
FIG. 12
DON'T support board or panel AWAY from the cut.
Cutting (Fig. 10)
Place the wider portion of the saw shoe on that part of the workpiece
which is solidly supported, not on the section that will fall off when the
cut is made. As an example, Figure 10 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 to go off the line, don't try to force it back on.
Release the trigger switch and allow blade to come to a complete stop.
Then you can withdraw the saw, sight anew, and start a new cut slightly
inside the wrong one. Withdraw the saw if you must shift the cut. Forcing
a correction inside the cut can stall the saw and lead to kickback.
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