Makita 5603R Instruction Manual page 6

9. Causes and Operator Prevention of Kickback:
– kickback is a sudden reaction to a pinched, bound
or misaligned saw blade, causing an uncontrolled
saw to lift up and out of the workpiece toward the
operator;
– when the blade is pinched or 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 the result of saw misuse and/or incorrect
operating procedures or conditions and can be
avoided by taking proper precautions as given
below.
• Maintain a firm grip with both hands on the
saw and position your arms to resist kickback
forces. Position your body to either side of the
blade, but not in line with the blade. Kickback
could cause the saw to jump backwards, but kick-
back forces can be controlled by the operator, if
proper precautions are taken.
• When blade is binding, or when interrupting a
cut for any reason, release the trigger and hold
the saw motionless in the material until the
blade comes to a complete stop. Never attempt
to remove the saw from the work or pull the saw
backward while the blade is in motion or kick-
back may occur. Investigate and take corrective
actions to eliminate the cause of blade binding.
• When restarting a saw in the workpiece, centre
the saw blade in the kerf and check that saw
teeth are not engaged into the material. If saw
blade is binding, it may walk up or kickback from
the workpiece as the saw is restarted.
• Support large panels to minimise the risk of
blade pinching and kickback. Large panels tend
to sag under their own weight. Supports must be
placed under the panel on both sides, near the line
of cut and near the edge of the panel.
To minimize the risk of blade pinching and kickback.
When cutting operation requires the resting of the
saw on the workpiece, the saw should be rested on
the larger portion and the smaller piece cut off. (Fig.
2 & 3)
• Do not use dull or damaged blades. Unsharp-
ened or improperly set blades produce narrow kerf
causing excessive friction, blade binding and kick-
back. Keep blade sharp and clean. Gum and wood
pitch hardened on blades slows saw and
increases potential for kickback. Keep blade clean
by first removing it from tool, then cleaning it with
gum and pitch remover, hot water or kerosene.
Never use gasoline.
• Blade depth and bevel adjusting locking levers
must be tight and secure before making cut. If
blade adjustment shifts while cutting, it may cause
binding and kickback.
• Use extra caution when making a "plunge cut"
into existing walls or other blind areas. The
protruding blade may cut objects that can cause
kickback. For plunge cuts, retract lower guard
using retracting handle.
6
• ALWAYS hold the tool firmly with both hands.
NEVER place your hand or fingers behind the
saw. If kickback occurs, the saw could easily jump
backwards over your hand, leading to serious per-
sonal injury. (Fig. 4)
• Never force the saw. Forcing the saw can
cause uneven cuts, loss of accuracy, and pos-
sible kickback. Push the saw forward at a speed
so that the blade cuts without slowing.
10. Check lower guard for proper closing before
each use. Do not operate the saw if lower guard
does not move freely and close instantly. Never
clamp or tie the lower guard into the open posi-
tion. If saw is accidentally dropped, lower guard may
be bent. Raise the lower guard with the retracting
handle and make sure it moves freely and does not
touch the blade or any other part, in all angles and
depths of cut. To check lower guard, open lower
guard by hand, then release and watch guard clo-
sure. Also check to see that retracting handle does
not touch tool housing. Leaving blade exposed is
VERY DANGEROUS and can lead to serious per-
sonal injury.
11. Check the operation of the lower guard spring. If
the guard and the spring are not operating prop-
erly, they must be serviced before use. Lower
guard may operate sluggishly due to damaged
parts, gummy deposits, or a build-up of debris.
12. Lower guard should be retracted manually only
for special cuts such as "plunge cuts" and
"compound cuts." Raise lower guard by retract-
ing handle and as soon as blade enters the
material, the lower guard must be released. For
all other sawing, the lower guard should operate
automatically.
13. Always observe that the lower guard is covering
the blade before placing saw down on bench or
floor. An unprotected, coasting blade will cause the
saw to walk backwards, cutting whatever is in its
path. Be aware of the time it takes for the blade to
stop after switch is released. Before setting the tool
down after completing a cut, be sure that the lower
guard has closed and the blade has come to a com-
plete stop.
14. Use the appropriate riving knife for the blade
being used. For the riving knife to work, it must be
thicker than the body of the blade but thinner than
the tooth set of the blade.
15. Adjust the riving knife as described in this
instruction manual. Incorrect spacing, positioning
and alignment can make the riving knife ineffective
in preventing kickback.
16. Always use the riving knife except when plunge
cutting. Riving knife must be replaced after plunge
cutting. Riving knife causes interference during
plunge cutting and can create kickback.
17. For the riving knife to work, it must be engaged
in the workpiece. The riving knife is ineffective in
preventing kickback during short cuts.
18. Do not operate the saw if riving knife is bent.
Even a light interference can slow the closing rate of
a guard.
19. Use extra caution when cutting damp wood,
pressure treated lumber, or wood containing
knots. Adjust speed of cut to maintain smooth
advancement of tool without decrease in blade
speed.