DeWalt DW831 Instruction Manual page 11

To start the tool, squeeze the trigger switch (A). To turn the tool off,
release the switch. The tool can be locked on for continuous use by
holding the trigger switch depressed while you depress the switch
locking button next to the trigger. Hold the lock-on button (B) in as
you gently release the trigger. Release the locking button and the tool
will continue to run. To turn the tool off from a locked on condition,
squeeze and release the trigger once.
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
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
FIG. 3
and may cause wheel breakage.
5. Remove the tool from the work surface
before turning the tool off. Allow the tool
to stop rotating before laying it down.
10˚ - 30°
Edge grinding and cutting wheels should
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.
Sanding With Abrasive Discs
DW831
When using an abrasive disc and rubber
backing pad, hold the tool so that an angle
of 10° to 15° exists between the disc and
the work, as shown. Using an angle of 5˚ to
15˚ will allow you to produce a smooth
surface. If only the outer edge of the sanding
disc is pressed flat against the work, the
9
FIG. 4
FIG. 5
5˚ - 15°