Ryobi RMS-1830 Betriebsanleitung Seite 41

10.10 CUTTING CROWN MOULDING
Your mitre saw is ideal for cutting crown moulding. In fact, it is usually the best tool for the job.
In order to fit properly, crown moulding must be compound mitred with extreme accuracy.
Both contact surfaces of a crown moulding against the ceiling and the wall of the room are at angles that add up to exactly 90°.
Crown moulding often has a top back angle (where it is flat against the ceiling) of 52° and a bottom back angle
(where it fits flat against the wall) of 38°.
10.11 LAY THE CROWN MOULDING FLAT ON THE MITRE TABLE
See Figure 30.
To use this method for accurately cutting crown moulding for 90° inside or outside corners, lay the crown moulding's widest
internal surface flat on the mitre table and push the crown moulding against the fence.
When setting the bevel and mitre angles for compound mitres, remember that the settings are interdependent; changing
one angle changes the other angle as well.
Keep in mind that the angles for crown moulding must be very precise and are difficult to set. Since it is very easy for these
angles to drift, the settings should first be tested on an offcut. Furthermore, as walls frequently do not meet at exactly 90°,
you will need to adjust the settings accordingly.
The settings in the chart below can be used for cutting crown moulding with 52° and 38° angles. When cutting crown
moulding using this method, the bevel angle should be set to 33.85°. The mitre angle should be set to 31.62° to the right
or left, depending on the type of cut required. The moulding must be placed flat on the mitre table. The following table gives
the angles and position of the crown moulding on the mitre table.
Bevel Angle Setting
33.85°
33.85°
33.85°
33.85°
Fig. 30
CROWN MOULDING FLAT ON THE MITRE TABLE.
A. CEILING
B. WALL
C. FENCE
D. TOP EDGE AGAINST FENCE =
• LEFT SIDE, INSIDE CORNER
• RIGHT SIDE, OUTSIDE CORNER
E. MITRE TABLE
10.12 CUTTING A WARPED WORKPIECE
See Figures 31 and 32.
When cutting a warped workpiece, always make sure it is positioned on the mitre table with the convex side against
the fence as shown in Figure 31.
If the warped workpiece is positioned the wrong way as shown in Figure 32, it will pinch the blade near the completion
of the cut.
WARNING: To avoid kickback and serious personal injury, never put the concave edge of a bowed or warped
workpiece against the fence.
Fig. 31
RIGHT
Fig. 32
WRONG
Type of Cut
Left side, inside corner
1. Position top of crown moulding against fence.
2. Mitre table set right 31.62°.
3. Keep left end after cutting.
Right side, inside corner
1. Position bottom of crown moulding against fence.
2. Mitre table set left 31.62°.
3. Keep left end after cutting.
Left side, outside corner
1. Position bottom of crown moulding against fence.
2. Mitre table set left 31.62°.
3. Keep right end after cutting.
Right side, outside corner
1. Position top of crown moulding against fence.
2. Mitre table set right 31.62°.
3. Keep right end after cutting.
F. INSIDE CORNER
G. FENCE
H. OUTSIDE CORNER
I. BOTTOM EDGE AGAINST FENCE =
• RIGHT SIDE, INSIDE CORNER
• LEFT SIDE, OUTSIDE CORNER
J. MITRE TABLE
41
GB