Cutting Compound Miters; Cutting Base Moldings; Cutting Crown Molding - DeWalt DW717 Instruction Manual

CUTTING COMPOUND MITERS
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 16.
NOTE: If the cutting angle varies from cut to cut, check
that the bevel clamp knob and the miter lock knob are
securely tightened. These knobs must be tightened after
making any changes in bevel or miter.
The chart shown on Page 16 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"
(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 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 26 ° exterior angles
(Angle A, Figure 15), 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
settings or] saw.
CUTTING BASE MOLDING
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 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 4.75" (121 mm) 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. Miter left 45 °
2. Save left side of cut
Right side
1. Miter Right 45 °
2. Save right side of cut
OUTSIDE CORNER:
Left side
1. Miter right at 45 °
FIG. 17
FENCE
TABLE
CROWN MOLDING FLAT ON TABLE
AND AGAINST FENCE
FIG. 18
BOTTOM SIDE
OF MOLDING DW 7084 CROWN
MOLDING FENCE
TOP SIDE
OF MOLDING
TABLE
F E NC E \
_L____
CROWN MOLDING BETWEEN FENCE AND TABLE
2. Save left side of cut
Right side
1. Miter left at 45 °
2. Save right side of cut
Material up to 6.5" (159 mm) can be cut as described
above.
CUTTING CROWN MOLDING
Your miter 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 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
31.62 ° left and right for cutting crown molding at the proper
12
FIG. 19
BLADE
RIGHT
FENCE
FIG. 20
FENCE
angle and bevel stop pawls at 33.85 ° left and right. There
is also a mark on the Bevel scale at 33.85 °.
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 90 °, 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
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.