Rate Of Feed; Feeding Too Quickly; Feeding Too Slowly - Craftsman 320.27683 Operator's Manual

RATE OF FEED (Figs. 25 and 25a)
The proper rate of feed depends on several factors: the hardness and moisture
content of the workpiece, the depth of cut, and the cutting diameter of the bit.
When cutting shallow grooves in soft woods such as pine, you may use a faster
rate of feed. When making deep cuts in hardwoods such as oak, you should use
a slower rate of feed.
FEEDING TOO QUICKLY (Fig. 25}
Clean and smooth cuts can only be achieved
when the cutter bit is rotating at a relatively
high speed, taking very small bites, producing
tiny, clean-cut chips.
Forcing the feed of the cutter bit forward
too quickly slows the rotational speed of the
cutter bit, and the bit takes bigger bites as it
rotates. Bigger bites cause bigger chips and
a rough finish. This forcing action can also
cause the router motor to overheat.
Fig. 25
Bit Shank
Cut
TOO FAST
Cutter
Under extreme force-feeding conditions, the
speed can become so slow and the bites
become so large that chips become partially
cut off, causing splintering and gouging of
the workpiece.
The router will make clean, smooth cuts if
allowed to run freely without the overload of
forced feeding. You can detect forced feeding
by the sound of the motor. Its usual high-pitched
whine will sound lower and stronger as it loses
speed. Holding the router against the workpiece
will also be strained and harder to do.
Fig. 25a
Bit Shank
Cut Cutter
TOO SLOW
FEEDING TOO SLOWLY (Fig. 25a)
When you feed the cutter bit too slowly, the rotating cutter bit does not cut into
new wood rapidly enough to take a bite. Instead, it scrapes away sawdust-like
particles. This scraping produces heat, which can glaze, burn, and mar the cut in
the workpiece and, in extreme cases, overheat the cutter bit.
When the cutter bit is scraping instead of cutting, the router is more difficult to
control as you feed it.
With almost no load on the motor, the cutter bit has a tendency to bounce
off the sides of the cut in the workpiece, producing a cut with a rippled finish
instead of clean straight sides.
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