Craftsman 315.175101 Operator's Manual page 15

DIRECTION (INTERNAL)
Whenever you are routing a groove, your travel
should be in a direction that places whatever guide
you are using at the right-hand side. In short, when
the guide is positioned as shown in the first part of
Figure 12, tool travel should be left to right and
counterclockwise around curves. When the guide is
positioned as shown in the second part of Figure 12,
tool travel should be right to left and clockwise around
curves. If there is a choice, the first setup is generally
the easiest to use. In either case, the sideways thrust
you use is against the guide.
GUIDE OUTSIDE
ROTATION
ROTATION
GUIDE INSIDE
ROTATION
GUIDE
ROTATION
FEED
OPERATION
THRUST
FEED
GUIDE
THRUST
Fig. 12
DETERMINING DEPTH OF CUT
As previously mentioned, the depth of cut is important
because it affects the rate of feed that, in turn, affects
the quality of the cut (and, also, the possibility of
damage to your router motor and bit). A deep cut
requires a slower feed than a shallow one, and a too
deep cut will cause you to slow the feed so much that
the bit is no longer cutting, it is scraping, instead.
Making a deep cut is never advisable. The smaller
bits — especially those only 1/16 inch (1.6 mm) in
diameter — are easily broken off when subjected to
too much side thrust. A large enough bit may not be
broken, but if the cut is too deep a rough cut will result
— and it may be very difficult to guide and control the
bit as desired. For these reasons, we recommend that
you do not exceed 1/8 in. depth of cut in a single
pass, regardless of the bit size or the softness or
condition of the workpiece. See Figure 13.
To make deeper cuts it is therefore necessary to
make as many successive passes as required,
lowering the bit 1/8 in. for each new pass. In order to
save time, do all the cutting necessary at one depth
setting, before lowering the bit for the next pass. This
will also assure a uniform depth when the final pass is
completed. See Figure 14.
DEPTH
OF CUT
1ST.
2ND.
PASS
PASS
15
WIDTH
OF CUT
Fig. 13
2ND. PASS
1ST. PASS
Fig. 14