Ryobi MS181 - Manual (Page 29)

Page 29
CUTTING CROWN MOLDING
Your compound miter saw does an excellent job of
cutting crown molding. In general, compound miter
saws do a better job of cutting crown molding than
any other tool made.
In order to fit properly, crown molding must be com-
pound mitered with extreme accuracy.
The two contact surfaces on a piece of crown molding
that fit flat against the ceiling and the wall of a room
are at angles that, when added together, equal
exactly 90°. Most crown molding has a top rear angle
(the section that fits flat against the ceiling) of 52° and
a bottom rear angle (the section that fits flat against
the wall) of 38°.
LAYING MOLDING FLAT ON THE
MITER TABLE
See Figure 39.
To use this method for accurately cutting crown
molding for a 90° inside or outside corner, lay the
molding with its broad back surface flat on the miter
table and against the fence.
When setting the bevel and miter angles for com-
pound miters, remember that the settings are interde-
pendent; changing one angle changes the other angle
as well.
Keep in mind that the angles for crown moldings are
very precise and difficult to set. Since it is very easy
for these angles to shift, all settings should first be
tested on scrap molding. Also, most walls do not have
angles of exactly 90°, therefore, you will need to fine
tune your settings.
OPERATION
CEILING
W
A
L
L
OUTSIDE
CORNER
INSIDE
CORNER
CROWN MOLDING FLAT ON MITER TABLE
38 °
52 °
FENCE
MITER TABLE
TOP EDGE AGAINST FENCE =
LEFT SIDE, INSIDE CORNER
RIGHT SIDE, OUTSIDE CORNER BOTTOM EDGE AGAINST FENCE =
RIGHT SIDE, INSIDE CORNER
LEFT SIDE, OUTSIDE CORNER
FENCE
MITER TABLE
Fig. 39