Sears 315.17473 - Manual (Page 9)

OPERATION
DEPTH OF CUT
As previously mentioned, the depth of cut is important be­
cause it affects the rate of feed which, in turn, affects the
quality of a 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 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 you do not exceed 1/8 inch depth of cut in a single pass,
regardless of the bit size or the softness or condition of the
workpiece. See Figure 10.
To make deeper cuts it is therefore necessary to make as
many successive passes as required, lowering the bit 1/8
inch 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 11.
DIRECTION OF FEED AND THRUST
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 during 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 direction that keeps the
sharp edges of the bit continuously biting straight into new
(uncut) wood.
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 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 set-up is generally the easiest to
use. In either case, the sideways thrust you use is against the
guide.
DEPTH
'l OF CUT WIDTH OF CUT
Fig.10
2ND. PASS
1ST. PASS
2ND. PASS
1ST. PASS
Fig. 11
GUIDE OUTSIDE
GUIDES
FEED
ROTATION
THRUST
FEED
GUIDE INSIDE Fig. 12
ROUTING WITH GUIDE BUSHINGS
When using the Template Guide Bushings Item No. 9-25082
with your router, you must visually center the bit with the
bushing before beginning your cut. Your router subbase may
be adjusted by loosening the sorews holding the subbase to
your router. Be sure clamping lever is securely locked before
centering bit in bushing. After centering bit with bushing
tighten screws firmly..
WARNING: FAILURE TO CENTER BIT WITH
BUSHING OR TO FIRMLY TIGHTEN SCREWS
AFTER CENTERING COULD CAUSE BITTO COME
IN CONTACT WITH BUSHING RESULTING IN
SERIOUS INJURY.
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