RIDGID R2901 Operator's Manual page 12

OPERATION
 Notice the chips being produced as you cut. If the router
is fed too slowly, it will scorch or burn the wood. If fed
too fast, it will take large chips out of the wood and leave
gouge marks.
Test a cut on a scrap piece of the workpiece before you
begin. Always grasp and hold the router firmly with both
hands.
If you are making a small diameter, shallow groove 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 bit is a large one, the cut is deep, or the workpiece 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.
FEEDING TOO FAST
See Figure 16, page 18.
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 you force the router to move forward too fast, the RPM of
the bit becomes slower than normal in relation to its forward
movement. As a result, the bit must take bigger bites as it
revolves. Bigger bites mean bigger chips and a rougher
finish. Also, because bigger bites require more power, the
router motor may become 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). This causes splintering and gouging of
the workpiece.
The router is an extremely high-speed tool, and will make
clean, smooth cuts if allowed to run freely without the over-
load of a forced feed. 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 hold-
ing the tool will be noticeably increased.
FEEDING TOO SLOWLY
See Figure 17, page 18.
It is possible to spoil a cut by moving the router forward too
slowly. When you advance the router into the work too slowly,
the revolving bit does not dig into new wood fast enough
to take a bite; instead, it merely scrapes away sawdust-like
particles. Scraping produces heat, which can glaze, burn,
or mar the cut and in extreme cases, can overheat the bit,
destroying its hardness.
When the bit is scraping instead of cutting, controlling the
router is more difficult. With practically no load on the mo-
tor, the bit revolves at close to top RPM, and has 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 produced may have
rippled, instead of straight, sides.
Feeding too slowly can also cause the router to take off in a
wrong direction from the intended line of cut. Always grasp
and hold the router firmly with both hands when routing.
You can detect when you are feeding the router too slowly by
the runaway, high-pitched sound of the motor or by feeling
the wiggle of the bit in the cut.
DEPTH OF CUT
See Figures 18 - 19, page 18.
Depth of cut is important because it affects the rate of feed
that, in turn, affects the quality of the cut and the possibility
of damage to the tool's motor and bit.
A deep cut requires a slower feed than a shallow one. A cut
that is too deep will slow the feed so that the bit is scraping
rather than cutting. A too deep cut can cause smaller bits
to be broken off. Bits that are 1/16 in. in diameter are easily
broken off when subjected to too much side thrust. A large
enough bit is not likely to break, but attempting a cut that is
too deep may result in a rough cut, and it may be difficult to
guide and control the bit as desired. It is recommended that
you do not exceed 1/8 in. depth or width of cut in a single
pass, regardless of the bit size or the softness or condition
of the workpiece.
To make deeper cuts, make as many successive passes as
needed, lowering the bit 1/8 in. for each new pass. To save
time, perform all the cutting necessary at one depth setting
before lowering the bit for the next pass. This will insure a
uniform depth when you complete the final pass.
NOTE: Do not remove more than 1/8 in. x 1/8 in. in a single
pass. Excessive depth or width of cut can result in loss of
control and the possibility of serious personal injury.
12 - English