DeWalt DCG412 Guide D'utilisation page 21

FIG. 10A
Wheels thicker than
1/8" (3.17 mm)
threaded locking
flange
backing flange
NOTE: If the wheel spins after the threaded locking flange is
tightened, check the orientation of the threaded locking flange. If a
thin wheel is installed with the pilot on the locking flange against the
wheel, it will spin because the height of the pilot prevents the locking
flange from holding the wheel.
SURFACE GRINDING WITH GRINDING WHEELS (FIG. 11)
1. Allow the tool to reach full speed before touching the tool to the
work surface.
2. Apply minimum pressure to the work surface, allowing the tool
to operate at high speed. Grinding rate is greatest when the tool
operates at high speed.
3. Maintain a 20° to 30° angle between
the tool and work surface.
4. Continuously move the tool in a
forward and back motion to avoid
creating gouges in the work surface.
5. Remove the tool from work surface
before turning tool off. Allow the tool to
stop rotating before laying it down.
EDGE GRINDING WITH GRINDING WHEELS (FIG. 12)
CAUTION: Wheels used for edge grinding and cutting may break
or kick back if they bend or twist while the tool is being used to do
FIG. 10B
Wheels 1/8" (3.17 mm)
and thinner
threaded locking
flange
backing flange
FIG. 11
20˚–30˚
19
cut-off work. In all edge grinding/cutting operations, the open side of
the guard must be positioned away from the operator. Edge grinding/
cutting with a Type 27 wheel must be limited to shallow cutting and
notching—less than 1/2" (13 mm) in depth when the wheel is new.
Reduce the depth of cutting/notching equal to the reduction of the
wheel radius as it wears down. Refer to pages 14 and 15 for more
information. Edge grinding/cutting with a Type 1 wheel requires usage
of a Type 1 guard.
1. Allow the tool to reach full speed before touching the tool to the
work surface.
2. Apply minimum pressure to the work
surface, allowing the tool to operate
at high speed. Grinding rate is
greatest when the tool operates at
high speed.
3. Position yourself so that the open-
underside of the wheel is facing
away from you.
4. Once a cut is begun and a notch
is established in the workpiece, do
not change the angle of the cut.
Changing the angle will cause the
wheel to bend and may cause wheel
breakage. Edge grinding wheels are
not designed to withstand side pressures caused by bending.
5. Remove the tool from the work surface before turning the tool off.
Allow the tool to stop rotating before laying it down.
WARNING: Do not use edge grinding/cutting wheels for surface
grinding applications if the wheel label has forbidden such use
because these wheels are not designed for side pressures
encountered with surface grinding. Wheel breakage and serious
personal injury may result.
FIG. 12