Depth Of Cut; Direction Of Feed And Thrust - Craftsman 315.268350 Operator's Manual

DEPTH OF CUT
As previously mentioned, the depth of cut is important
because it affects the rate of feed which, in tum, affects
the quality of a cut (and, also, the possibility of damage to
your 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, in-
stead.
DEPTH
OF CUT _'- WIDTH OF CUT
Making a deep cut is never advisable. The smaller bits --
especially those only 1116 inch in diameter -- are easily
broken off when subjected to too much side thrust. A large
enough bit may not be broken off, 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 several passes be made to reach deeper
cuts. See Figure 16.
To make deeper cuts it is therefore necessary to make as
many successive passes as required, Iowedng the bit for
each new pass. In order to save time, do all the cutting
necessary at one depth setting, before Iowedng the bit for
the next pass. This will also assure a uniform depth when
the final pass is completed. See Figure 17.
DIRECTION OF FEED AND THRUST
See Figure 18.
The router motor and bit revolve in a clockwise direction.
This gives the tool a slight tendency to twist (in your
hands) in a counterclockwise direction, especially when
the motor revs up (as at starting).
Because of the extremely high speed of bit rotation dudng
a "proper feeding" operation, there is very little kickback to
contend with under normal conditions. However, should
the bit strike a knot, hard grain, foreign object, etc. that
would affect the normal progress of the cutting action,
there will be a slight kickback -- sufficient to spoil the
trueness of your cut if you are not prepared. Such a
kickback is always in the direction opposite to the direction
of bit rotation.
To guard against such a kickback, plan your set-up and
direction of feed so that you will always be thrusting the
tool -- to hold it against whatever you are using to guide
the cut- in the same direction that the leading edge of
the bit is moving. In short, the thrust should be in a direc-
tion that keeps the sharp edges of the bit continuously
biting straight into new (uncut) wood.
Fig.16
2ND. iASs_IS i PASS
2ND. PASS
Fig. 17
ROUTER FEED
D
ROUTER FEED ROTATION
DIRECTION Fig. 18
GUIDE OUTSIDE
ROTATION _
THRUST_ )
FEED GUIDE
GUIDE INSIDE
ROUTING
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 19, tool travel should be
left to right and counterclockwise around curves. When the
guide is positioned as shown in the second part of Figure
19 tool travel should be dght to left and clockwise around
curves. If there is a choice, the first set-up is generally the
ROTATION __
/
FEED
THRUST
Fig. 19
easiest to use. In either case, the sideways thrust you use
is against the guide.
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