Craftsman 315.175170 Operator's Manual page 20

PROPER RATE OF FEED
Professionalrouting depends upon careful setup and
proper rate of feed which is learned through prectica and
use. The proper rate of feed Is dependent upon:
• hardness and moisture content of the workpiece
• depth of cut
• cutting diameter of the cutter
When cutting shallow grooves in soft woods such as pins,
a faster rate of feed can be used.When making cuts in
hardwoods such as oak, a slower r,_teof feed is required.
Severa! factors will help you select the proper rate of feed.
• Choose the rate that does not slow down the motor.
• Choose the rate at which the cutter advances firmly
end surely to produce a continuous spkral of uniform
chips or a smooth edge.
• Listen to the sound of the motor. A high-pitched sound
means you are feeding too slowly.A strained, lower
pitched sound signals force feeding.
• Check the progress of each cut. Too slow feeding can
cause the router to take off in a wrong direction from
the intended line of cut. Force feeding increases the
strain of holding the too( and resultsin loss of speed.
• Notice the chips being produced as you cut. If the
router [s fed too slowly, it will scorch or burn the wood.
If fed too fast, it will take large chips out of the wood
end leave gouge marks.
Test a cut on a scrap piece of the workplece before you
begin. Always grasp and hold the router firmly with both
hands.
If you are making a small diameter, shaTlowgroove in soft,
dry wood, the proper feed rate may be determined by the
speed at which you can travel the router along the guide
line. If the cutter is a large one, the cut is deep, or the
workpiece is herd to cut, the proper feed may be a very
slow one. A crees grain cut may requirea slower pace
than an identical w(th grain cut in the same workpieca.
FEEDING TOO FAST
See Figure 20.
Clean, smooth routing and edge shaping can be done
only when the cutter Is revolving at e relatively high speed
and is taking very sm_.((bites to produce tiny, cleanly
severed chips, if you force the router to move forward too
fast, the RPM of the cutter becomes slower than normat
In relation to Its forward movement. As a result, the cutter
must take bigger bites as it revolves.Bigger bites mean
bigger chips and a rougher finish. Also, because bigger
bites require more power, the muter motor may become
overtoaded.
Under extreme force-feeding conditions, the relative
RPM of the cutter can become so slow--and the bites it
has to take so large--that chipswill be partially knocked
off (rather than fully out off). This causes splintering and
gouging of the workpieca.
The router is an extremely high-speed tool, and will make
clean, smooth cuts if allowed to run freely without the
ovedoad of a forced feed. You can always detect rome
feeding by the sound of the motor. Its high-pitched whine
wi1_ sound lower and strongeras it loses speed. Also, the
strain of holding the tool will be noticeably increased.
TOOFAS'r Fig. 20
20