Dewalt DCS781B Instruction Manual

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ENGLISH

Cutting Crown Molding

Your miter 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 mitered 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 miter saw has special pre‑set miter 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 miter 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

18

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 Outside corner

Left side

1. Bevel left 33.9°

2. Miter table set at right 31.62°

3. Save left end of cut

1. Bevel right 33.9°

2. Miter table set at left 31.62°

3. Save left end of cut

Right side

1. Bevel right 33.9°

2. Miter table set at left 31.62°

3. Save right end of cut

1. Bevel left 33.9°

2. Miter table set at right 31.62°

3. Save right end of cut

When setting bevel and miter angles for all compound miters, 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

12

and the saw

table

18

, as shown in FigureV. Use of the crown molding fence accessory (DW7084) is highly

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 miter 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 Outside corner

Left side

1. Miter right 45°

2. Save right side of cut

1. Miter left 45°

2. Save right side of cut

Right side

1. Miter left 45°

2. Save left side of cut

1. Miter right 45°

2. Save left side of cut

Inside corner Outside corner

Left side

1. Miter left 45°

2. Save left side of cut

1. Miter right 45°

2. Save left side of cut

Right side

1. Miter right 45°

2. Save right side of cut

1. Miter left 45°

2. Save right side of cut

Material up to 6.5" (165 mm) can be cut as describedabove.

Cutting Compound Miters (Fig. S)

A compound miter is a cut made using a miter angle and a bevel angle at the same time.

This is the type of cut used to make frames or boxes with slanting sides like the one shown in

FigureR.

NOTE: If the cutting angle varies from cut to cut, check that the bevel lock knob and the miter

lock handle are securely locked. These must be locked after making any changes in bevel

ormiter.

The chart at the end of this manual (Table 1) will assist you in selecting the proper bevel and

miter settings for common compound miter cuts. To use the chart, select the desired angleA

(Fig.S) of your project and locate that angle on the appropriate arc in the chart. From that

point follow the chart straight down to find the correct bevel angle and straight across to find

the correct miterangle.

Set your saw to the prescribed angles and make a few trial cuts. Practice fitting the cut pieces

together until you develop a feel for this procedure and feel comfortable withit.

Example: To make a 4‑sided box with 26º 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 miter

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.

Cutting Trim Molding and Other Frames (Fig. R)

Sketch 2in FigureR shows a joint made by setting the miter arm at 45º to miter the two

boards to form a 90º corner. To make this type of joint, set the bevel adjustment to zero and

the miter arm to 45º. Once again, position the wood with the broad flat side on the table and

the narrow edge against thefence.

The two sketches in FigureR are for four‑sided objectsonly.

As the number of sides changes, so do the miter and bevel angles. The chart below gives the

proper angles for a variety ofshapes.

– EXAMPLES –

NUMBER OF SIDES MITER OR BEVEL ANGLE

4 45°

5 36°

6 30°

7 25.7°

8 22.5°

9 20°

10 18°

The chart assumes that all sides are of equal length. For a shape that is not shown in the chart,

use the following formula: 180º divided by the number of sides equals the miter (if the material

is cut vertically) or bevel angle (if the material is cut layingflat).

Cutting Picture Frames, Shadow Boxes and Other Four-Sided

Projects (Fig. R)

To best understand how to make the items listed here, we suggest that you try a few simple

projects using scrap wood until you develop a “feel” for yoursaw.

Your saw is the perfect tool for mitering corners like the one shown in FigureR. Sketch1shows

a joint made by using the bevel adjustment to bevel the edges of the two boards at 45º each

to produce a 90º corner. For this joint the miter arm was locked in the zero position and the

bevel adjustment was locked at 45º. The wood was positioned with the broad flat side against

the table and the narrow edge against the fence. The cut could also be made by mitering right

and left with the broad surface against thefence.

Support for Long Pieces



WARNING: To reduce the risk of serious personal injury, turn tool off, and remove

the battery pack before transporting, making any adjustments, cleaning,

repairing, or removing/installing attachments or accessories. An accidental

start‑up can causeinjury.

ALWAYS SUPPORT LONGPIECES.

Never use another person as a substitute for a table extension; as additional support for a

workpiece that is longer or wider than the basic miter saw table or to help feed, support or pull

theworkpiece.

Support long workpieces using any convenient means such as sawhorses or similar devices to

keep the ends fromdropping.

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 6.5" (165 mm) Vertically Against

the Fence (Fig. L, T)

NOTE: Use the slide lock transport lever

61

, shown in Figure L1, when cutting base molding

measuring from 3” to 6.5” (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.

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Dewalt DCS781B 60V MAX Brushless 12in. Double Bevel Sliding Miter Saw

Instruction Manual - Page 16