Edging With A Pilot Bit - Craftsman 320.27669 Operator's Manual

EDGING WiTH A PILOT BIT (Figs. 19 and 19a
The arbor-type bits with pilots are excellent
for edge shaping of any workpiece edge that
is straight, or is curved at a curvature as great
or greater than the radius of the bit to be
used. The pilot prevents the bit from making
an excessively deep cut, and holding the pilot
firmly in contact with the workpiece edge
throughout prevents the cut from becoming
too shallow.
Fig. 19
Motor Housing
Pilot Fixed Base Work-
sub-base piece
TOP EDGE SHAPING
Whenever the workpiece thickness, together
with the desired depth of cut (as adjusted by
router depth setting) are such that only the
top part of the edge is to be shaped (leaving
at least a 1/16 inch. thick uncut portion at the Fig. 19a
bottom), the pilot can ride against the uncut
portion, which serves to guide it (Fig. 19).
If the workpiece is too thin or if the bit is
set so low that there will be no uncut edge
against which to ride the pilot, an extra
board must be placed under the workpiece
to act as a guide (Fig. 19a). This "guide"
board must have exactly the same contour - Guide Board
straight or curved - as the workpiece edge.
If it is positioned so that its edge is flush WHOLE EDGE SHAPING
with the workpiece edge, the bit will make a full cut (in as far as the bit radius).
On the other hand, if the guide is positioned as shown in Fig. 19a (out from the
workpiece edge), the bit will make less than a full cut - which will alter the shape
of the finished edge.
NOTE: The size (diameter) of the pilot that is used determines the maximum cut
width that can be made with the pilot against the workpiece edge (the small pilot
exposes all of the bit; the large one reduces this amount by 1/16 inch). Any of
the piloted cutter bits can be used without a pilot for edge shaping with guides.
WARNING: Always securely clamp your workpiece and keep a firm grip on
the router base with both hands at all times. Failure to do so could result in loss
of control causing possible serious personal injury.
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