Craftsman 320.28190 - Manual (Page 30)

RATE OF FEED (Figs. 18 and 18a)
The proper rale of feed de­
pends on several factors: the
hardness and moisture content
of the work piece, the depth of
cut, and the cutting diameter of
the bit. When you are cutting
shallow grooves in soft woods
such as pine, you may use a
faster rate of feed. When mak­
ing deep cuts in hardwoods
such as oak, you should use a
slower rate of feed.
FEEDING TOO FAST (Fig. 18)
Clean and smooth finished
cuts can only be achieved
when the cutting bit is rotating
at a relatively high speed, tak­
ing very small bites, producing
tiny, clean cut chips.
Forcing the feed of the cutting
bit forward too fast slows the
RPM of the cutting bit, and the
bit takes bigger bites as it ro­
tates. Bigger bites mean bigger
chips and a rough finish. This
forcing action can also cause
the router motor to overheat.
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 work piece.
The router will make clean, smooth cuts if allowed to run freely without the over­
load 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.
Flolding the router against the work piece wilt also be sirained and harder to do,
FEEDING TOO SLOW (Fig. 18a)
When you feed the cutting bit too slowly, the rotating cijitting bit does not cut into
new wood fast enough to take a bite. Instead, it scrapes away sawdust-like par­
ticles. This scraping produces heat, which can glaze, burn and mar the cut in the
work piece and, in extreme cases, overheat the cutting bit.
When the cutting bit is scraping instead of cutting, the ijouter is more difficult to
control as you feed it.
28190 Manual Revised 07C409 Page 30