Routing; Rate-Of-Feed; Force Feeding; Too Slow Feeding - Craftsman 315.17560 Owner's Manual

OPERATION
WARNING: ALWAYS WEAR SAFETY GLASSES OR
EYESHIELDS WHEN USING YOUR ROUTER. IF THE
CUTTING OPERATION IS DUSTY, ALSO WEAR A
FACE OR DUST MASK. FAILURE TO DO SO COULD
RESULT IN DUST OR CHIPS BEING THROWN IN
YOUR EYES RESULTING IN POSSIBLE SERIOUS IN-
JURY.
ROUTING
For ease of operation your router has two handles,
one on each side of the router base. When using
your router hold it firmly with both hands as shown
in Fig. 5. Remain alert and watch what you are doing.
Do not operate router when fatigued.
RATE.OF-FEED
IMPORTANT: The whole "secret" of professional
routing and edge shaping lies in selecting the proper
rate-of-feed.., and in making a careful set-up for the
cut to be made.
FORCE FEEDING
Clean, smooth routing and edge shaping can be
done only when the bit is revolving at a relatively
high speed and is taking very small bites to produce
tiny, cleanly severed chips. If the router is forced to
move forward at a fast pace, the rpm of the bit is
slower than normal in relation to its forward move-
ment -- and the bit must necessarily take bigger
bites as it revolves. "Bigger bites" mean bigger
chips, and a rougher finish. Moreover, bigger chips
require more power -- and the router motor can
become sufficiently overloaded to slow down and
further aggravate the condition. In fact, under ex-
treme force-feeding conditions the relative rpm of
the bit can become so slow -- and the bites it has to
take so large -- that chips will be partially knocked
off (rather than fully cut off), with resulting splinter-
ing and gouging of the workpiece. See Fig. 6.
Your Craftsman Router is an extremely high-speed
tool (25,000 rpm no-load speed), and will make clean,
smooth cuts if allowed to run freely without the
overload of a forced (too fast) feed. What constitutes
"force feeding" depends upon three things: Bit size,
depth-of-cut, and workpiece characteristics. The
larger the bit and/or the deeper the cut, the more
slowly the router can be moved forward. And, if the
wood is very hard, knotty, gummy or damp, the
operation must be slowed still more.
You can always detect "force feeding" by the sound
of the motor. Its high-pitched whine will sound lower
and stronger as it loses speed. Also, the strain of
holding the tool will be noticeably increased.
TOO FAST
TOO SLOW
Fig. 6
TOO SLOW FEEDING
Fig. 5
It is also possible to spoil a cut by moving the router
forward too slowly. When it is advanced into the
work too slowly a revolving bit doesn't dig into new
wood fast enough to take a bite; instead, it simply
scrapes away sawdust-like particles. Scraping pro-
duces heat, which can glaze or burn and mar the cut
m in extreme cases, can even overheat the bit so as
to destroy its hardness.
In addition, it is more difficult to control a router
when the bit is scraping instead of cutting. With
practically no load on the motor the bit will be revolv-
ing at close to top rpm, and will have a much greater
than normal tendency to bounce off the sides of the
cut (especially, if the wood has a pronounced grain
with hard and soft areas). As a result, the cut produc-
ed may have rippled, instead of straight, sides
and, unless very firmly held, the router might even
take off in a wrong direction from the intended cut
line. See Fig. 6.
You can detect "too-slow feeding" by the runaway,
too-highly pitched sound of the motor; or, by feeling
the "wiggle" of the bit in the cut.
PROPER FEEDING
The right feed is neither too fast nor too slow. It is
the rate at which the bit is being advanced firmly and
surely to produce a continuous spiral of uniform
chips -- without hogging into the wood to make
large individual chips nor, on the other hand, to
create only sawdust. If you .are making a small
diameter, shallow groove in soft, dry wood, the pro-
per feed may be about as fast as you can travel your
router along your guide line. Contrarywise, if the bit
is a large one, the cut is deep, and/or the wood is
hard to cut, the proper feed may be a very slow one.
Then, again, a cross-grain cut may require a slower
pace than an identical with grain cut in the same
workpiece.
There is no fixed rule. You will learn by experience...
by listening to the tool motor and by feeling the pro-
gress of each cut. If at all possible, always test a cut
on a scrap of the workpiece wood, beforehand.
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