DeWalt DW378 Guide D'utilisation page 2

11x20,DW378 7/21/04 12:51 PM Page 2
Changing Blades
CAUTION: Turn off and unplug the tool before making any adjustments or
removing/installing attachments or accessories.
TO INSTALL THE BLADE
1. Place inner clamp washer (G) on saw spindle with the large flat surface facing out toward
the blade (Fig. 1).
2. Retract the lower blade guard (H) and place blade on saw spindle against the inner clamp
washer, making sure that the blade will rotate in the proper direction (the direction of the rota-
tion arrow on the saw blade and the teeth must point in the same direction as the direction
of rotation arrow on the saw). Do not assume that the printing on the blade will always be fac-
ing you when properly installed. When retracting the lower blade guard to install the blade,
check the condition and operation of the lower blade guard to assure that it is working prop-
erly. Make sure it moves freely and does not touch the blade or any other part, in all angles
and depths of cut.
3. Place outer clamp washer (I) on saw spindle with the large flat surface against the blade and
the wording on the outer clamp washer facing you.
4. Thread blade clamping screw (F) into saw spindle by hand (screw has left-hand threads and
must be turned counterclockwise to tighten).
5. Depress the blade lock (J) while turning the saw spindle with the blade wrench until the
blade lock engages and the blade stops rotating (Fig. 3).
6. Tighten the blade clamping screw firmly with the blade wrench.
NOTE: Never engage the blade lock while saw is running, or engage in an effort to stop the tool.
Never turn the saw on while the blade lock is engaged. Serious damage to your saw will result.
TO REPLACE THE BLADE
1. To loosen the blade clamping screw (F), depress the blade lock (J) and turn the saw spin-
dle with the blade wrench until the blade lock engages and the blade stops rotating. With
the blade lock engaged, turn the blade clamping screw clockwise with the blade wrench
(screw has left-hand threads and must be turned clockwise to loosen).
2. Remove the blade clamping screw (F) and outer clamp washer (I) only. Remove old blade.
3. Clean any sawdust that may have accumulated in the guard or clamp washer area and check
the condition and operation of the lower blade guard as previously outlined. Do not lubricate
this area.
4. Select the proper blade for the application (see Blades). Always use blades that are the cor-
rect size (diameter) with the proper size and shape center hole for mounting on the saw
spindle. Always assure that the maximum recommended speed (rpm) on the saw blade
meets or exceeds the speed (rpm) of the saw.
5. Follow steps 2 through 6 under To Install the Blade, making sure that the blade will rotate
in the proper direction.
LOWER BLADE GUARD
WARNING: The lower blade guard is a safety feature which reduces the risk of serious
personal injury. Never use the saw if the lower guard is missing, damaged, misassembled
or not working properly. Do not rely on the lower blade guard to protect you under all cir-
cumstances. Your safety depends on following all warnings and precautions as well as
proper operation of the saw. Check lower guard for proper closing before each use as
outlined in Additional Safety Rules for Circular Saws. If the lower blade guard is missing
or not working properly, have the saw serviced before using. To assure product safety
and reliability, repair, maintenance and adjustment should be performed by an autho-
rized service center or other qualified service organization, always using identical
replacement parts.
Cutting Depth Adjustment
CAUTION: Turn off and unplug the tool before making any adjustments or
removing/installing attachments or accessories.
Hold the saw firmly. Raise the depth adjustment lever (C) to loosen and move shoe to obtain
the desired depth of cut, as shown. Make sure the depth adjustment lever has been retightened
(lowered) before operating saw (Fig. 4).
Your saw is equipped with a carbide tipped saw blade for long life and efficient cutting.
Setting the saw at the proper cutting depth keeps blade friction to a minimum, removes saw-
dust from between the blade teeth, results in cooler, faster sawing and reduces the chance of
kickback. Align the appropriate mark on the depth adjustment strap with triangle on the upper
blade guard. Your depth is set.
For the most efficient cutting action using a carbide tipped saw blade, set the Depth Adjustment
so that about one half of a tooth projects below the surface of the wood to be cut (Figure 5).
A method of checking for the correct cutting depth is shown in Figure 6. Lay a piece of the mate-
rial you plan to cut along the side of the blade, as shown in the figure, and observe how much
tooth projects beyond the material.
Bevel Angle Adjustment
CAUTION: Turn off and unplug the tool before making any adjustments or
removing/installing attachments or accessories.
The full range of the bevel adjustment is from 0 TO 50 DEGREES. The quadrant is graduated
in increments of 5 degrees.
On the front of the saw is a bevel angle adjustment mechanism (Fig. 8) consisting of a calibrated
quadrant (L) and a lever (M). To set the saw for a bevel cut, raise to loosen the Bevel Adjustment
lever and tilt shoe to the desired angle by aligning the pointer (N) with the desired angle mark.
Retighten lever firmly by lowering it.
KERF INDICATOR
The front of the saw shoe has a kerf indicator (Figure 10) for vertical and bevel cutting. This indi-
cator enables you to guide the saw along cutting lines penciled on the material being cut. The
indicator lines up with the left (outer) side of the saw blade, which makes the slot or "kerf" cut
by the moving blade fall to the right of the indicator. The ribs on the front of the shoe are at 1/2"
(13mm) spacing.
OPERATION
Switch (Fig. 1)
Pull the trigger switch (B) to turn the motor ON. Releasing the trigger turns the motor OFF. This
tool has no provision to lock the switch in the ON position, and should never be locked ON in
any way.
Workpiece Support
Figure 11 and 13 show proper sawing position. Figure 12 and 14 show an unsafe condition.
Hands should be kept away from cutting area, and power cord is positioned clear of the cutting
area so that it will not get caught or hung up on the work.
To avoid kickback, DO support board or panel NEAR the cut, (Fig. 11, 13). DON'T support board
or panel away from the cut (Fig. 12, 14). When operating the saw, keep the cord away from the
cutting area and prevent it from becoming hung up on the work piece.
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 14 illustrates typical hand support of
the saw.
ALWAYS DISCONNECT SAW BEFORE MAKING ANY ADJUSTMENTS! 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 saw it.
Cutting
Support the work so that the waste will be on your left. Place the wider portion of the saw shoe
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 13 illustrates the RIGHT way to cut off the end of a board,
and Figure 14 the WRONG way. Always clamp work. Don't try to hold short pieces by hand!
Remember to support cantilevered and overhanging material. Use caution when sawing mate-
rial 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
it working without much decrease in speed.
Sawhook
Your saw has a convenient saw hook to allow you to hang the saw on a joist or rafter. The
sawhook folds flat against the tool handle when not in use.
To use the sawhook, push down on the hook and rotate it outwards from the handle. It will latch
into position. (Fig.15)
To return the sawhook to its stored position, push down on the hook and rotate it back towards
the handle. It will latch into position.
Kickback
When the saw blade becomes pinched or twisted in the cut, kickback can occur. The saw is
thrust rapidly back 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 backward. When 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 causing pinching of the blade. (Figure 12)
B. Cutting through material supported at the outer ends only (see Figure 12). As the mater-
ial 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 verti-
cal direction. The falling cut off piece can pinch the blade.(Figure 14)
D. Cutting off long narrow strips (as in ripping). The cut off strip can sag or twist closing the
kerf and pinching the blade.
FIG. 1
A
B
D
E
C
F
H
FIG. 2 FIG. 3
J
J
LOOSEN
(clockwise)
DESSERRER
(vers la droite)
AFLOJAR
(dirección de las
manillas del reloj)
FIG. 5
FIG. 4
C
FIG. 7 FIG. 8
K
FIG. 10
FIG. 9
FIG. 11 FIG. 12
FIG. 13 FIG. 14
E. Snagging the lower guard on a surface below the material being cut momentarily reduc-
ing 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
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. See 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. Extended reach or operating 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 unit up to clear blade can lead to twist if not done carefully.
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
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 CUTS
Bevel cuts require special operator attention to proper cutting techniques - especially guid-
ance of the saw. Both blade angle to the shoe 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
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 Set-Up" and "Operation"
for procedures and techniques that will minimize the occurrence of kickback.
MAINTENANCE
Lubrication
Your saw has a sealed gear housing filled to the proper level with a high-performance gear lubri-
cant. Adding excessive amounts of lubricant, or adding improper lubricant can cause leakage or
premature gear failure.
I
G
F
H
TIGHTEN
(counterclockwise)
SERRER
(vers la gauche)
AJUSTAR
(dirección contraria
a las manillas
del reloj)
FIG. 6
N L M
1/2"
45˚
0˚
13 mm
FIG. 15