RIDGID R4221 Operator's Manual page 37

OPERATION
CUTTING WARPED MATERIAL
See Figures 50 - 51.
When cutting warped material, always make sure it is
positioned on the miter table with the convex side against
the fence as shown in figure 50.
If the warped material is positioned the wrong way as shown
in figure 51, it will pinch the blade near the completion of
the cut.
WARNING:
To avoid kickback and serious personal injury, never
position the concave edge of bowed or warped
material against the fence.
37 - English
RIGHT
WRONG
Fig. 50
Fig. 51