Cutting Trim Molding And Other Frames; Cutting Compound Miters; Cutting Base Molding; Cutting Crown Molding - DeWalt DW717-XE Instruction Manual

The two sketches in Figure 15 are for four side objects only.
As the number of sides changes, so do the mitre and bevel angles. The
chart below gives the proper angles for a variety of shapes.
(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 mitre (if the material is cut vertically) or bevel
angle (if the material is cut laying flat).
- EXAMPLES -
NO. SIDES ANGLE MITER OR BEVEL
4
5
6
7
8
9
10
CUTTING COMPOUND MITRES
A compound mitre is a cut made using a mitre 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 16.
NOTE: If the cutting angle varies from cut to cut, check that the bevel
clamp knob and the mitre lock knob are securely tightened. These knobs
must be tightened after making any changes in bevel or mitre.
Table 1: Compound Mitre Cut will assist you in selecting the proper bevel
and mitre settings for common compound mitre cuts. To use the chart,
select the desired angle "A" (Figure 16) 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 mitre 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,
Figure 16), 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 settings on saw.

CUTTING BASE MOLDING

ALWAYS MAKE A DRY RUN WITHOUT POWER BEFORE MAKING ANY
CUTS.
Straight 90º cuts:
Position the wood against the fence and hold it in place as shown in
Figure 11. Turn on the saw, allow the blade to reach full speed and
lower the arm smoothly through the cut.
CUTTING BASE MOLDING UP TO 121 mm (4.75") HIGH
VERTICALLY AGAINST THE FENCE
Position material as shown in Figure 11.
All cuts made with the back of the molding against the fence and bottom
of the molding against the base.
INSIDE CORNER:
Left side
1. Mitre left 45°
2. Save left side of cut
FIG. 14
45°
36°
30°
FIG. 16
25.7°
22.5°
20°
18°
Right side
1. Mitre Right 45°
2. Save right side of cut
OUTSIDE CORNER:
Left side
1. Mitre right at 45°
2. Save left side of cut
Right side
1. Mitre left at 45°
2. Save right side of cut
Material up to 159 mm (6.5") can be cut as described above.

CUTTING CROWN MOLDING

Your mitre saw is better suited to the task of cutting crown molding than
any other type 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 90º. Most, but not all, crown
molding has a top rear angle (the section that fits flat against the ceiling)
of 52º and a bottom rear angle (the part that fits flat against the wall) of
38º.
Your mitre saw has special pre-set mitre latch points at 31.62º left and
right for cutting crown molding at the proper angle and bevel stop pawls
at 33.85º left and right. There is also a mark on the Bevel scale at 33.85º.
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.
INSTRUCTIONS FOR CUTTING CROWN MOLDING
LAYING FLAT AND USING THE COMPOUND FEATURES
1. Molding laying with broad back surface down flat on saw table
(Figure 17).
2. The settings below are for All Standard (U.S.) crown molding with
52° and 38° angles.
FIG. 15
A
B
ANGLE "A"
PRETESTING WITH SCRAP MATERIAL
IS EXTREMELY IMPORTANT!
9 9
BEVEL SETTING TYPE OF CUT
LEFT SIDE, INSIDE CORNER:
1. Top of molding against fence
33.85° Left
2. Mitre table set right 31.62°
3. Save left end of cut
RIGHT SIDE, INSIDE CORNER:
1. Top of molding against fence.
33.85° Right
2. Mitre table set at left 31.62°
3. Save right end of cut
LEFT SIDE, OUTSIDE CORNER:
1. Top of molding against fence.
33.85° Right
2. Mitre table set at left 31.62°
3. Save left end of cut
RIGHT SIDE, OUTSIDE CORNER:
1. Top of molding against fence
33.85° Left
2. Mitre table set 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
Place the molding on the table at an angle between the fence and the saw
table, as shown in Figure 18. 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 mitre angle can be made
without affecting the bevel angle. This way, when corners other than 90º
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 18.
2. The angled "flats" on the back of the molding must rest squarely on
the fence and base of the saw.
INSIDE CORNER:
Left side
1. Mitre right at 45°
2. Save the right side of cut
Right side
1. Mitre left at 45°
2. Save left side of cut
OUTSIDE CORNER:
Left side
1. Mitre left at 45°
2. Save right side of cut