Operation - DeWalt DW840 Instruction Manual

OPERATION

WARNING: To reduce the risk of injury, turn unit off
and disconnect it from power source before installing and
removing accessories, before adjusting or when making
repairs. An accidental start-up can cause injury.
Switching On and Off (Fig. 1)
WARNING: Before using the tool, check that the side handle is
tightened securely.
WARNING: Hold the side handle and body of the tool firmly to
maintain control of the tool at start up and during use and until the
wheel or accessory stops rotating. Make sure the wheel has come to
a complete stop be fore laying the tool down.
1. To run the tool, press the lock off button (B) and the On/Off switch
(A).
2. To stop the tool, release the On/Off switch.
WARNING: Do not switch the tool On or Off when under load.
Grinding
Using a depressed center Type 27 wheel,
hold the tool at an angle of approximately
10˚–30° to the work for grinding. Most
Type 27 wheels are not designed for
cutting operations.
Edge Cutting
WARNING: Edge grinding and cutting can be performed only with
Type 27 wheels that are designed and specified for this purpose.
Protect yourself during edge cutting by directing the open side of the
guard toward a surface.
CAUTION: Wheels used for edge grinding and cutting may break
or kick back if they bend or twist while the tool is being used. 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 10 and 11 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
2. Apply minimum pressure to the work surface, allowing the tool
3. Position yourself so that the open-underside of the wheel is facing
4. Once a cut is begun and a notch is
FIG. 3
5. Remove the tool from the work surface
Edge grinding and cutting wheels should
10˚ - 30°
contact the work surface only at the edge
of the wheel, not on the top or bottom of
the wheel. Side pressure on the wheel could
lead to breakage of the wheel.
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.
9
work surface.
to operate at high speed. Grinding rate is greatest when the tool
operates at high speed.
away from you.
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.
before turning the tool off. Allow the tool
to stop rotating before laying it down.
FIG. 4