Cutting Crown Molding; Maintenance - DeWalt DCS781 Original Instructions Manual

English
Example: To make a 4‑sided box with 26 ° exterior angles (Angle A, Fig. S), use the upper right
arc. Find 26 ° on the arc scale. Follow the horizontal intersecting line to either side to get mitre
angle setting on saw (42 °). Likewise, follow the vertical intersecting line to the top or bottom
to get the bevel angle setting on the saw (18 °). Always try cuts on a few scrap pieces of wood
to verify the settings on the saw.
8 siDED BOX
SET THIS BEVEL ANGLE ON SAW
Cutting Base Molding (Fig. T)
ALWAYS MAKE A DRY RUN WITHOUT POWER BEFORE MAKING ANY CUTS.
Straight 90 ° cuts:
Position the wood against the fence and hold it in place as shown in Figure T. Turn on the saw,
allow the blade to reach full speed and lower the arm smoothly through the cut.
Cutting Base Molding up to 165 mm Vertically Against the Fence
(Fig. L, T)
nOTE: Use the slide lock lever, shown in Figure L1 when cutting base molding measuring
from 76 mm to 165 mm high vertically against the fence.
Position material as shown in Figure T.
All cuts should be made with the back of the molding against the fence and with the bottom
of the molding against the table.
inside corner
1. Mitre left 45°
Left side
2. Save left side of cut
1. Mitre right 45°
Right side
2. Save right side of cut
Material up to 165 mm can be cut as described above.

Cutting Crown Molding

Your mitre saw is better suited to the task of cutting crown molding than any tool made. In
order to fit properly, crown molding must be compound mitreed with extreme accuracy.
The two flat surfaces on a given piece of crown molding are at angles that, when added
together, equal exactly 90 °. Most, but not all, crown molding has a top rear angle (the section
that fits flat against the ceiling) of 52 ° and a bottom rear angle (the part that fits flat against
the wall) of 38 °.
Your mitre saw has special pre‑set mitre latch points at 31.6 ° left and right for cutting crown
molding at the proper angle and bevel stop pawls at 33.9 ° left and right. There is also a mark
on the bevel scale at 33.9 °.
The chart below gives the proper settings for cutting crown molding. (The numbers for
the mitre and bevel settings are very precise and are not easy to accurately set on your
saw.) Since most rooms do not have angles of precisely 90º, you will have to fine tune your
settings anyway.
PRETEsTing WiTh sCRAP MATERiAl is EXTREMElY iMPORTAnT!
Instructions for Cutting Crown Molding Laying Flat and Using the
Compound Features (Fig. A, U)
1. Molding laying with broad back surface down flat on saw table
2. Top of molding against fence 12 .
3. The settings below are for all standard (U.S.) crown molding with 52 ° and 38 ° angles.
inside corner
1. Bevel left 33.9°
Left side 2. Mitre table set at right 31.62°
3. Save left end of cut
1. Bevel right 33.9°
Right side 2. Mitre table set at left 31.62°
3. Save right end of cut
16
sQUARE BOX
6 siDED BOX
Outside corner
1. Mitre right 45°
2. Save left side of cut
1. Mitre left 45°
2. Save right side of cut
18 .
Outside corner
1. Bevel right 33.9°
2. Mitre table set at left 31.62°
3. Save left end of cut
1. Bevel left 33.9°
2. Mitre table set at right 31.62°
3. Save right end of cut
When setting bevel and mitre angles for all compound mitres, remember that:
The angles presented for crown moldings are very precise and difficult to set exactly. Since
they can easily shift slightly and very few rooms have exactly square corners, all settings should
be tested on scrap molding.
PRETEsTing WiTh sCRAP MATERiAl is EXTREMElY iMPORTAnT!
Alternative Method for Cutting Crown Molding (Fig. V)
Place the molding on the table at an angle between the sliding fence
table , as shown in Figure V. Use of the crown molding fence accessory (DW7084) is highly
18
recommended because of its degree of accuracy and convenience. The crown molding fence
accessory is available for purchase from your local dealer.
The advantage to cutting crown molding using this method is that no bevel cut is required.
Minute changes in the mitre angle can be made without affecting the bevel angle. This way,
when corners other than 90 ° are encountered, the saw can be quickly and easily adjusted for
them. Use the crown molding fence accessory to maintain the angle at which the molding will
be on the wall.
Instructions for Cutting Crown Molding Angled Between the Fence and
Base of the Saw for All Cuts
1. Angle the molding so the bottom of the molding (part which goes against the wall when
installed) is against the fence and the top of the molding is resting on the base of the saw,
as shown in Figure V..
2. The angled "flats" on the back of the molding must rest squarely on the fence and base of
the saw.
inside corner
1. Mitre right 45°
Left side
2. Save right side of cut
1. Mitre left 45°
Right side
2. Save left side of cut
Special Cuts
NEVER MAKE ANY CUT UNLESS THE MATERIAL IS SECURED ON THE TABLE AND AGAINST
THE FENCE.
Aluminum Cutting (Fig. A, W)
ALWAYS USE THE APPROPRIATE SAW BLADE MADE ESPECIALLY FOR CUTTING ALUMINUM.
These are available at your local D WALT retailer or D
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due to their size, shape or surface finish, may require the use of a clamp or fixture to prevent
movement during the cut. Position the material so that you will be cutting the thinnest cross
section, as shown in Figure W. Figure W also illustrates the wrong way to cut these extrusions.
Use a stick wax cutting lubricant when cutting aluminum. Apply the stick wax directly to the
saw blade 39 before cutting. Never apply stick wax to a moving blade.
The wax, available at most hardware stores, provides proper lubrication and keeps chips from
adhering to the blade.
Be sure to properly secure workpiece.
Refer to saw Blades under Optional Accessories for correct saw blade.
Bowed Material (Fig. X, Y)
When cutting bowed material always position it as shown in Figure X and never like that
shown in Figure Y. Positioning the material incorrectly will cause it to pinch the blade near the
completion of the cut.
Cutting Plastic Pipe or Other Round Material
Plastic pipe can be easily cut with your saw. It should be cut just like wood and ClAMPED
OR hElD FiRMlY TO ThE FEnCE TO KEEP iT FROM ROlling. This is extremely important
when making angle cuts.
Cutting Large Material (Fig. Z)
Occasionally you will encounter a piece of wood a little too large to fit beneath the lower
guard. If this occurs, simply place your right thumb on the upper side of the guard and roll the
guard up just enough to clear the workpiece, as shown in Figure Z. Avoid doing this as much
as possible, but if need be, the saw will operate properly and make the bigger cut. NEVER TIE,
TAPE, OR OTHERWISE HOLD THE GUARD OPEN WHEN OPERATING THIS SAW.

MAINTENANCE

Your D WALT power tool has been designed to operate over a long period of time with a
e
minimum of maintenance. Continuous satisfactory operation depends upon proper tool care
and regular cleaning.

WARNING: To reduce the risk of serious personal injury, turn machine off and
disconnect battery pack before making any adjustments or removing/installing
attachments or accessories. An accidental start‑up can cause injury.

WARNING: If the saw blade is worn replace it with a new sharp blade.
DO NOT use lubricants or cleaners (particularly spray or aerosol) in the vicinity of the plastic
guard. The polycarbonate material used in the guard is subject to attack by certain chemicals.
1. All bearings are sealed. They are lubricated for life and need no further maintenance.
2. Periodically clean all dust and wood chips from around AND UNDER the base and the
rotary table. Even though slots are provided to allow debris to pass through, some dust
will accumulate.
12 and the saw
Outside corner
1. Mitre left 45°
2. Save right side of cut
1. Mitre right 45°
2. Save left side of cut
WALT service center. Certain workpieces,
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