Craftsman 315.175130 - Manual (Page 10)

OPERATION
FREEHAND ROUTING
See Figure 9.
When used freehand, your router becomes a flexible
and versatile tool. This flexibility makes it possible to
easily rout signs, relief sculptures, etc.
There are two basic techniques
for freehand routing:
■ Routing letters, grooves, and patterns into wood.
See Figure 9.
■ Routing out the background, leaving the letters
or pattern raised above the surface.
When freehand routing, we suggest the following:
■ Draw or layout the pattern on workpiece.
■ Choose the appropriate cutter.
Note: A core box or V-groove bit is often used for
routing letters and engraving objects. Straight bits
and ball mills are often used to make relief
carvings. Veining bits are used to carve small,
intricate details.
U Rout the pattern in two or more passes. Make the
first pass at 25% of the desired depth of cut. This
will provide better control as well as being a guide
for the next pass.
■ Do not rout deeper than 1/8 in. per pass or cut.
VV WARNING: Do not use large router bits for
freehand routing. Use of large router bits when
freehand routing could cause loss of control or
create other hazardous conditions that could
cause possible serious personal injury. When
. using a router table, large router bits should be
used for edging only. Do not use router bits that
are larger in diameter than the opening in router
base for any purpose.
RATE OF FEED
IMPORTANT: The whole “secret" of professional
routing and edge shaping lies in making a careful
setup for the cut to be made and in selecting the
proper rate of feed.
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 or, on the other hand, to create only
sawdust. If you are making a small diameter, shallow
groove in soft, dry wood, the proper feed may be
about as fast as you can travel your router along your
guide line. On the other hand, if the bit is a large one,
the cut is deep or the wood is hard to cut, the proper
feed may be a very slow one. 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
from practice and use. The best rate of feed is
determined by listening to the sound of the router
motor and by feeling the progress of each cut. Always
test a cut on a scrap piece of the workpiece wood,
beforehand.
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 your router is forced to move
forward too fast, the RPM of the bit becomes slower
than normal in relation to its fonward movement. As a
result, the bit must take bigger bites as it revolves.
“Bigger bites” mean bigger chips, and a rougher
finish. Bigger chips also require more power, which
could result in the router motor becoming overloaded.
Under extreme 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
splintering and gouging of the workpiece.
See Figure 10.
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