Rate Of Feed; Feeding Too Rapidly - Craftsman 320.28212 Operator's Manual

RATE OF FEED (Figs. 15 and 15a)
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 RAPIDLY
(Fig. 15)
Clean and smooth finished
cuts can only be achieved
when the cutting bit is rotating
at a relatively high speed,
taking very small bites, and
producing tiny, clean-cut chips.
Forcing the feed of the cutting
bit forward too rapidly slows
the RPM of the cutting bit, and
the bit takes larger bites as it
rotates. Larger bites mean larger
chips and a rough finish. This
forcing action can also cause
the router motor to overheat.
Fig. 15
Cut
TOO FAST
Cutter
Fig. 15a
Cut
TOO SLOW
Cutter
Under extreme force-feeding conditions, the RPMs 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 it is 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 more difficult to do.
FEEDING TOO SLOWLY (Fig. 15a)
When you feed the cutting bit too slowly, the rotating cutting 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 cutting bit.
28212 Manual_Revised_07-0713 Page 28