DeWalt Power Tools Instruction Manual

Instruction Manual
DW831, DW840
Heavy-Duty Medium Angle Trigger Switch Grinder
English
Definitions: Safety Alert Symbols and Words
This instruction manual uses the following safety alert symbols and words to alert you to hazardous situations and your risk
of personal injury or property damage.
DANGER: Indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury.
WARNING: Indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.
CAUTION: Indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury.
(Used without word) Indicates a safety related message.
NOTICE: Indicates a practice not related to personal injury which, if not avoided, may result in property damage.
Fig. A
9
2
8
5
1
6
7
DW831
3
2 Spindle lock button
3 Unthreaded backing flange (DW831)
4 Threaded locking flange (DW831)
6 Guard
7 Guard release lever
10
4
1 Spindle
5 Side handle
DW840
11
WARNING! Read all safety warnings and all
instructions. Failure to follow the warnings and
instructions may result in electric shock, fire and/or
serious injury.
WARNING: To reduce the risk of injury, read the
instruction manual.
8 On/Off switch
9 Lock-off button
10 Backing flange (DW840)
11 Clamp nut (DW840)
1
English
GENERAL POWER TOOL SAFETY WARNINGS
WARNING! Read all safety warnings and all
instructions. Failure to follow the warnings and
instructions may result in electric shock, fire and/or
serious injury.
SAVE ALL WARNINGS AND
INSTRUCTIONS FOR FUTURE
REFERENCE
The term “power tool” in the warnings refers to your mainsoperated (corded) power tool or battery-operated (cordless)
power tool.
1) Work Area Safety
a ) Keep work area clean and well lit. Cluttered or dark
areas invite accidents.
b ) Do not operate power tools in explosive
atmospheres, such as in the presence of
flammable liquids, gases or dust. Power tools
create sparks which may ignite the dust or fumes.
c ) Keep children and bystanders away while
operating a power tool. Distractions can cause you
to lose control.
2) Electrical Safety
a ) Power tool plugs must match the outlet. Never
modify the plug in any way. Do not use any
adapter plugs with earthed (grounded) power
tools. Unmodified plugs and matching outlets will
reduce risk of electric shock.
b ) Avoid body contact with earthed or grounded
surfaces such as pipes, radiators, ranges and
refrigerators. There is an increased risk of electric
shock if your body is earthed or grounded.
c ) Do not expose power tools to rain or wet
conditions. Water entering a power tool will increase
the risk of electric shock.
d ) Do not abuse the cord. Never use the cord for
carrying, pulling or unplugging the power tool.
Keep cord away from heat, oil, sharp edges or
moving parts. Damaged or entangled cords increase
the risk of electric shock.
e ) When operating a power tool outdoors, use an
extension cord suitable for outdoor use. Use of
a cord suitable for outdoor use reduces the risk of
electric shock.
f ) If operating a power tool in a damp location
is unavoidable, use a ground fault circuit
interrupter (GFCI) protected supply. Use of a GFCI
reduces the risk of electric shock.
3) Personal Safety
a ) Stay alert, watch what you are doing and use
common sense when operating a power tool. Do
not use a power tool while you are tired or under
the influence of drugs, alcohol or medication. A
moment of inattention while operating power tools
may result in serious personal injury.
2
b ) Use personal protective equipment. Always wear
eye protection. Protective equipment such as dust
mask, non-skid safety shoes, hard hat, or hearing
protection used for appropriate conditions will reduce
personal injuries.
c ) Prevent unintentional starting. Ensure the
switch is in the off position before connecting to
power source and/or battery pack, picking up or
carrying the tool. Carrying power tools with your
finger on the switch or energizing power tools that
have the switch on invites accidents.
d ) Remove any adjusting key or wrench before
turning the power tool on. A wrench or a key left
attached to a rotating part of the power tool may
result in personal injury.
e ) Do not overreach. Keep proper footing and
balance at all times. This enables better control of
the power tool in unexpected situations.
f ) Dress properly. Do not wear loose clothing or
jewelry. Keep your hair, clothing and gloves
away from moving parts. Loose clothes, jewelry or
long hair can be caught in moving parts.
g ) If devices are provided for the connection of dust
extraction and collection facilities, ensure these
are connected and properly used. Use of dust
collection can reduce dust-related hazards.
4) Power Tool Use and Care
a ) Do not force the power tool. Use the correct
power tool for your application. The correct power
tool will do the job better and safer at the rate for
which it was designed.
b ) Do not use the power tool if the switch does not
turn it on and off. Any power tool that cannot be
controlled with the switch is dangerous and must
be repaired.
c ) Disconnect the plug from the power source and/
or the battery pack from the power tool before
making any adjustments, changing accessories,
or storing power tools. Such preventive safety
measures reduce the risk of starting the power
tool accidentally.
d ) Store idle power tools out of the reach of children
and do not allow persons unfamiliar with the
power tool or these instructions to operate the
power tool. Power tools are dangerous in the hands
of untrained users.
e ) Maintain power tools. Check for misalignment or
binding of moving parts, breakage of parts and
any other condition that may affect the power
tool’s operation. If damaged, have the power
tool repaired before use. Many accidents are
caused by poorly maintained power tools.
f ) Keep cutting tools sharp and clean. Properly
maintained cutting tools with sharp cutting edges are
less likely to bind and are easier to control.
g ) Use the power tool, accessories and tool bits, etc.
in accordance with these instructions, taking
English
into account the working conditions and the
work to be performed. Use of the power tool for
operations different from those intended could result
in a hazardous situation.
5) Service
a ) Have your power tool serviced by a qualified
repair person using only identical replacement
parts. This will ensure that the safety of the power
tool is maintained.
SAFETY INSTRUCTIONS FOR ALL
OPERATIONS
Safety Warnings Common for Grinding,
Sanding, Wire Brushing, Polishing or
Abrasive, Cutting-Off Operations
a ) This power tool is intended to function as a
grinder, sander, wire brush, polisher or cut-off
tool. Read all safety warnings, instructions,
illustrations and specifications provided with
this power tool. Failure to follow all instructions
listed below may result in electric shock, fire and/or
serious injury.
b ) Do not use accessories which are not specifically
designed and recommended by the tool
manufacturer. Just because the accessory can
be attached to your power tool, it does not assure
safe operation.
c ) The rated speed of the accessory must be at least
equal to the maximum speed marked on the
power tool. Accessories running faster than their
rated speed can break and fly apart.
d ) The outside diameter and the thickness of your
accessory must be within the capacity rating of
your power tool. Incorrectly sized accessories cannot
be adequately guarded or controlled.
e ) Threaded mounting of accessories must match
the grinder spindle thread. For accessories
mounted by flanges, the arbor hole of the
accessory must fit the locating diameter of the
flange. Accessories that do not match the mounting
hardware of the power tool will run out of balance,
vibrate excessively and may cause loss of control.
f ) Do not use a damaged accessory. Before each
use inspect the accessory such as abrasive
wheels for chips and cracks, backing pad for
cracks, tear or excess wear, wire brush for loose
or cracked wires. If power tool or accessory
is dropped, inspect for damage or install an
undamaged accessory. After inspecting and
installing an accessory, position yourself and
bystanders away from the plane of the rotating
accessory and run the power tool at maximum
no-load speed for one minute. Damaged
accessories will normally break apart during this
test time.
g ) Wear personal protective equipment. Depending
on application, use face shield, safety goggles or
safety glasses. As appropriate, wear dust mask,
hearing protectors, gloves and workshop apron
capable of stopping small abrasive or workpiece
fragments. The eye protection must be capable
of stopping flying debris generated by various
operations. The dust mask or respirator must
be capable of filtrating particles generated by
your operation. Prolonged exposure to high intensity
noise may cause hearing loss.
h ) Keep bystanders a safe distance away from work
area. Anyone entering the work area must wear
personal protective equipment. Fragments of
workpiece or of a broken accessory may fly away and
cause injury beyond immediate area of operation.
i ) Hold the power tool by insulated gripping
surfaces only, when performing an operation
where the cutting accessory may contact hidden
wiring or its own cord. Cutting accessory contacting
a “live” wire may make exposed metal parts of the
power tool “live” and could give the operator an
electric shock.
j ) Position the cord clear of the spinning accessory.
If you lose control, the cord may be cut or snagged
and your hand or arm may be pulled into the
spinning accessory.
k ) Never lay the power tool down until the
accessory has come to a complete stop. The
spinning accessory may grab the surface and pull the
power tool out of your control.
l ) Do not run the power tool while carrying it at
your side. Accidental contact with the spinning
accessory could snag your clothing, pulling the
accessory into your body.
m ) Regularly clean the power tool’s air vents. The
motor’s fan will draw the dust inside the housing and
excessive accumulation of powdered metal may cause
electrical hazards.
n ) Do not operate the power tool near flammable
materials. Sparks could ignite these materials.
o ) Do not use accessories that require liquid
coolants. Using water or other liquid coolants may
result in electrocution or shock.
p ) Do not use Type 11 (flaring cup) wheels on this
tool. Using inappropriate accessories can result
in injury.
q ) Always use side handle. Tighten the handle
securely. The side handle should always be used to
maintain control of the tool at all times.
r ) When starting the tool with a new or
replacement wheel, or a new or replacement
wire brush installed, hold the tool in a well
protected area and let it run for one minute. If
the wheel has an undetected crack or flaw, it
should burst in less than one minute. If the wire
brush has loose wires, they will be detected.
3
English
Never start the tool with a person in line with the
wheel. This includes the operator.
s ) Use of accessories not specified in this manual
is not recommended and may be hazardous.
Use of power boosters that would cause the tool
to be driven at speeds greater than its rated speed
constitutes misuse.
t ) Use clamps or another practical way to secure
and support the workpiece to a stable platform.
Holding the work by hand or against your body leaves
it unstable and may lead to loss of control.
u ) Avoid bouncing the wheel or giving it rough
treatment. If this occurs, stop the tool and inspect the
wheel for cracks or flaws.
v ) Always handle and store wheels in a careful manner.
w ) Do not operate this tool for long periods of time.
Vibration caused by the operating action of this
tool may cause permanent injury to fingers,
hands, and arms. Use gloves to provide extra
cushion, take frequent rest periods, and limit daily
time of use.
Causes and Operator Prevention
of Kickback
Kickback is a sudden reaction to a pinched or snagged
rotating wheel, backing pad, brush or any other accessory.
Pinching or snagging causes rapid stalling of the rotating
accessory which in turn causes the uncontrolled power tool to
be forced in the direction opposite of the accessory’s rotation
at the point of the binding.
For example, if an abrasive wheel is snagged or pinched by
the workpiece, the edge of the wheel that is entering into the
pinch point can dig into the surface of the material causing
the wheel to climb out or kick out. The wheel may either jump
toward or away from the operator, depending on direction
of the wheel’s movement at the point of pinching. Abrasive
wheels may also break under these conditions.
Kickback is the result of tool misuse and/or incorrect operating
procedures or conditions and can be avoided by taking proper
precautions as given below:
a ) Maintain a firm grip on the power tool and
position your body and arm to allow you to resist
kickback forces. Always use auxiliary handle, if
provided, for maximum control over kickback or
torque reaction during start up. The operator can
control torque reaction or kickback forces, if proper
precautions are taken.
b ) Never place your hand near the rotating
accessory. Accessory may kickback over your hand.
c ) Do not position your body in the area where
power tool will move if kickback occurs. Kickback
will propel the tool in direction opposite to the wheel’s
movement at the point of snagging.
d ) Use special care when working corners, sharp
edges etc. Avoid bouncing and snagging the
accessory. Corners, sharp edges or bouncing have
4
a tendency to snag the rotating accessory and cause
loss of control or kickback.
e ) Do not attach a saw chain woodcarving blade
or toothed saw blade. Such blades create frequent
kickback and loss of control.
Safety Warnings Specific for Grinding
Operations
a ) Use only wheel types that are recommended for
your power tool and the specific guard designed
for the selected wheel. Wheels for which the power
tool was not designed cannot be adequately guarded
and are unsafe.
b ) The grinding surface of center depressed
wheels must be mounted below the plane of
the guard lip. An improperly mounted wheel that
projects through the plane of the guard lip cannot be
adequately protected.
c ) The guard must be securely attached to the
power tool and positioned for maximum safety,
so the least amount of wheel is exposed towards
the operator. The guard helps to protect the operator
from broken wheel fragments, accidental contact with
wheel and sparks that could ignite clothing.
d ) Wheels must be used only for recommended
applications. For example: do not grind with the
side of cut-off wheel. Abrasive cut-off wheels are
intended for peripheral grinding, side forces applied to
these wheels may cause them to shatter.
e ) Always use undamaged wheel flanges that
are of correct size and shape for your selected
wheel. Proper wheel flanges support the wheel
thus reducing the possibility of wheel breakage.
Flanges for cut-off wheels may be different from
grinding wheel flanges.
f ) Do not use worn down wheels from larger power
tools. Wheel intended for larger power tool is not
suitable for the higher speed of a smaller tool and
may burst.
Safety Warnings Specific for Sanding
Operations
a ) Do not use excessively oversized sanding disc
paper. Follow manufacturers recommendations,
when selecting sanding paper. Larger sanding
paper extending beyond the sanding pad presents a
laceration hazard and may cause snagging, tearing of
the disc or kickback.
Safety Warnings Specific for Polishing
Operations
a ) Do not allow any loose portion of the polishing
bonnet or its attachment strings to spin freely.
Tuck away or trim any loose attachment strings.
Loose and spinning attachment strings can entangle
your fingers or snag on the workpiece.
English
Safety Warnings Specific for Wire
Brushing Operations
a ) Be aware that wire bristles are thrown by the
brush even during ordinary operation. Do not
overstress the wires by applying excessive load
to the brush. The wire bristles can easily penetrate
light clothing and/or skin.
b ) If the use of a guard is recommended for wire
brushing, do not allow any interference of the
wire wheel or brush with the guard. Wire wheel
or brush may expand in diameter due to work and
centrifugal forces.
c ) Safety goggles or safety glasses with side shields
and a full face shield compliant with ANSI Z87.1
MUST be worn by the operator and others that
are within 50' (15.2 m) of the use of this product.
Additional Safety Information
WARNING: ALWAYS use safety glasses. Everyday
eyeglasses are NOT safety glasses. Also use face or
dust mask if cutting operation is dusty. ALWAYS WEAR
CERTIFIED SAFETY EQUIPMENT:
• ANSI Z87.1 eye protection (CAN/CSA Z94.3),
• ANSI S12.6 (S3.19) hearing protection,
• NIOSH/OSHA/MSHA respiratory protection.
WARNING: Some dust created by power sanding,
sawing, grinding, drilling, and other construction
activities contains chemicals known to the State
of California to cause cancer, birth defects or
other reproductive harm. Some examples of these
chemicals are:
• lead from lead-based paints,
• crystalline silica from bricks and cement and other
masonry products, and
• arsenic and chromium from chemicallytreated lumber.
Your risk from these exposures varies, depending on how
often you do this type of work. To reduce your exposure to
these chemicals: work in a well ventilated area, and work with
approved safety equipment, such as those dust masks that are
specially designed to filter out microscopic particles.
• Avoid prolonged contact with dust from power
sanding, sawing, grinding, drilling, and other
construction activities. Wear protective clothing and
wash exposed areas with soap and water. Allowing
dust to get into your mouth, eyes, or lay on the skin may
promote absorption of harmful chemicals.
WARNING: Use of this tool can generate and/
or disperse dust, which may cause serious and
permanent respiratory or other injury. Always use
NIOSH/OSHA approved respiratory protection
appropriate for the dust exposure. Direct particles
away from face and body.
WARNING: Always wear proper personal hearing
protection that conforms to ANSI S12.6 (S3.19)
during use. Under some conditions and duration
of use, noise from this product may contribute to
hearing loss.
CAUTION: When not in use, place tool on its side
on a stable surface where it will not cause a
tripping or falling hazard.
Air vents often cover moving parts and should be
avoided. Loose clothes, jewelry or long hair can be
caught in moving parts.
An extension cord must have adequate wire size
(AWG or American Wire Gauge) for safety. The smaller
the gauge number of the wire, the greater the capacity
of the cable, that is, 16 gauge has more capacity than 18
gauge. An undersized cord will cause a drop in line voltage
resulting in loss of power and overheating. When using
more than one extension to make up the total length,
be sure each individual extension contains at least the
minimum wire size. The following table shows the correct
size to use depending on cord length and nameplate
ampere rating. If in doubt, use the next heavier gauge. The
lower the gauge number, the heavier the cord.
•
•
Minimum Gauge for Cord Sets
Total Length of Cord in Feet
(meters)
120 V
25 (7.6) 50 (15.2) 100 (30.5) 150 (45.7)
240 V
50 (15.2) 100 (30.5) 200 (61.0) 300 (91.4)
Ampere Rating
More
Not
American Wire Gauge
Than More
Than
0
6
18
16
16
14
6
10
18
16
14
12
10
12
16
16
14
12
12
16
14
12
Not Recommended
The label on your tool may include the following symbols. The
symbols and their definitions are as follows:
V.......................... volts
or AC/DC..... alternating or
direct current
Hz........................ hertz
....................... Class II
min...................... minutes
Construction
or DC....... direct current
(double insulated)
....................... Class I Construction
no........................ no load speed
(grounded)
n.......................... rated speed
…/min............... per minute
....................... earthing terminal
BPM..................... beats per minute
...................... safety alert symbol
IPM...................... impacts per minute
...................... visible radiation
RPM..................... revolutions per
...................... wear respiratory
minute
protection
sfpm.................... surface feet per
...................... wear eye
minute
protection
SPM..................... strokes per minute
...................... wear hearing
A.......................... amperes
protection
W......................... watts
...................... read all
or AC............ alternating current
documentation
Volts
SAVE THESE INSTRUCTIONS FOR
FUTURE USE
5
English
Motor
Fitting and Removing the Guard
Be sure your power supply agrees with the nameplate
marking. Voltage decrease of more than 10% will cause loss
of power and overheating. DeWALT tools are factory tested;
if this tool does not operate, check power supply.
DW831 (Fig. B, C)
COMPONENTS (FIG. A)
WARNING: Never modify the power tool or any part
of it. Damage or personal injury could result.
Refer to Figure A at the beginning of this manual for a
complete list of components.
Intended Use
Your heavy-duty small angle grinder has been designed
for professional grinding, sanding, wire brush, and cut-off
applications at various work sites (i.e., construction sites).
DO NOT use under wet conditions or in presence of
flammable liquids or gases.
Your heavy-duty small angle grinders is a professional
power tool. DO NOT let children come into contact with the
tool. Supervision is required when inexperienced operators
use this tool.
ASSEMBLY AND ADJUSTMENTS
WARNING: To reduce the risk of serious personal
injury, turn unit off and disconnect it from
power source before making any adjustments or
removing/installing attachments or accessories.
An accidental start-up can cause injury.
Attaching Side Handle (Fig. A)
WARNING: Before using the tool, check that the
handle is tightened securely.
Screw the side handle 5 tightly into one of the holes on
either side of the gear case. The side handle should always
be used to maintain control of the tool at all times.
Guards
CAUTION: Guards must be used with all grinding
wheels, cutting wheels, sanding flap discs,
wire brushes, and wire wheels. The tool may
be used without a guard only when sanding with
conventional sanding discs. Refer to Figure A to see
guards provided with the unit. Some applications may
require purchasing the correct guard from your local
dealer or authorized service center.
NOTE: Edge grinding and cutting can be performed with
Type 27 wheels designed and specified for this purpose;
6.35 mm thick wheels are designed for surface grinding
while thinner Type 27 wheels need to be examined for
the manufacturer's label to see if they can be used for
surface grinding or only edge grinding/cutting. A Type 1
guard must be used for any wheel where surface grinding
is forbidden. Cutting can also be performed by using a
Type 41 wheel and a Type 1 guard.
NOTE: See the Accessories Chart to select the proper guard
/ accessory combination.
6
CAUTION: Unplug the tool before mounting or
removing the guard. Guards must be used with all
grinding wheels and sanding flap discs, wire brushes
and wire wheels. The tool may be used without the
guard only when sand­ing with conventional sanding
discs. Before reconnecting the tool, depress and
release the rear part of the switch to ensure that the
tool is off.
Fitting Guard
CAUTION: Do not operate grinder with a loose guard
or the guard latch in the open position.
1. Open the guard latch 7 and align the arrow on the
guard with the arrow on the gear case.
2. Push the guard down until the guard lugs engage and
rotate freely in the groove on the gear case.
3. With the guard latch open, rotate the guard into the
working position providing maximum protection to the
user (Fig. C).
4. Close the guard latch to secure guard on gear case
(Fig. C).
NOTE: The guard is pre-adjusted to the diameter of the
spindle hub at the factory. If the guard needs further
adjustment after a period of use, perform the following ad­just­
ment. With the guard latch in the closed position tighten or
loos­en the adjustment screw 12 .
Removing Guard
1. Open the guard latch 7 and align the arrow on the
guard with the arrow on the gear case.
2. Pull the guard up until the guard lugs engage and rotate
freely in the groove on the gear case.
3. With the guard latch open, rotate the guard until the
arrows are aligned. (Fig. C).
4. Remove the guard.
CAUTION: Do not tighten adjusting screw with guard
latch in open position. Undetectable damage to the
guard or the mounting hub may result.
Fig. B
Fig. C
12
7
DW840 (Fig. D)
CAUTION: Unplug the tool before mounting or
removing the guard. Guards must be used with all
grinding wheels and sanding flap discs, wire brushes
and wire wheels. Before reconnecting the tool, depress
and release the rear part of the switch to ensure that
the tool is off.
English
Fitting Guard
CAUTION: Do not operate grinder with a loose guard
or the guard latch in the open position.
1. Place the angle grinder on a table, spindle up.
2. Press the guard down.
3. Position the guard between your body and the
work piece.
4. Tighten the screw holding the cinch collar firmly around
the neck of the spindle.
Fig. D
due to wheel breakage and wheel contact. See the
Accessories Chart for more information.
1. Place the tool on a table, guard up.
2. Install the unthreaded backing flange 3 (DW831), 10
(DW840) on spindle 1 with the raised center (pilot)
facing the wheel.
3. Place wheel 13 against the backing flange,
centering the wheel on the raised center (pilot) of the
backing flange.
4. While depressing the spindle lock button and with the
hex depressions facing away from the wheel, thread
the threaded locking flange 4 (DW831), 11 (DW840)
on spindle so that the lugs engage the two slots in
the spindle.
NOTE: If the wheel you are installing is more than 1/8"
(3.17 mm) thick, place the threaded locking flange on
the spindle so that the raised section (pilot) fits into the
center of the wheel. If the wheel you are installing is
1/8" (3.17 mm) thick or less, place the threaded locking
flange on the spindle so that the raised section (pilot) is
not against the wheel.
Fig. E
Removing Guard
1. Loosen the screw holding the cinch collar around the
neck of the spindle.
2. Lift up on the guard.
CAUTION: Do not tighten adjusting screw with guard
latch in open position. Undetectable damage to the
guard or the mounting hub may result.
CAUTION: Edge grinding can be performed with
Type 27 wheels designed and specified for this
purpose; 1/4" (6.35 mm) thick wheels are designed for
surface grinding while thinner Type 27 wheels need
to be examined for the manufacturer's label to see
if they can be used for surface grinding or only edge
grinding/cutting. Wheels where surface grinding is not
permitted cannot be used with this grinder.
Flanges and Wheels
CAUTION: Turn unit off and unplug the tool before
making any adjustments or removing or installing
attachments or accessories.
Over 1/8" (3.17 mm)
wheels
1/8" Or less (3.17 mm)
wheels
Locking flange
Locking flange
Backing Flange
Backing Flange
5. While depressing the spindle lock button, tighten the
threaded locking flange 4 (DW831), 11 (DW840):
a. Tighten the threaded locking flange using a
wrench 14 .
b. Tighten a keyless locking flange by hand. (Only use a
keyless locking flange if it is in perfect condition.)
6. To remove the wheel, depress the spindle lock button
and loosen the threaded locking flange.
Fig. F
14
14
Mounting Non-Hubbed Wheels (Fig. E, F)
WARNING: Failure to properly seat the flanges and/or
wheel could result in serious injury (or damage to the
tool or wheel).
CAUTION: Included flanges must be used with
depressed center Type 27/42 grinding wheels and
Type 1/41 cutting wheels. See the Accessories Chart
for more information.
WARNING: A closed, two-sided cutting wheel guard
is required when using abrasive cutting wheels or
diamond coated cutting wheels.
WARNING: Use of a damaged flange or guard or fail­
ure to use proper flange and guard can re­sult in injury
4
11
13
13
3
10
1
1
DW831
DW840
7
English
Mounting and Removing Hubbed
Wheels (Fig. A)
hub on the clamp nut into the center of san­ding disc
and backing pad.
4. Tighten the clamp nut by hand. Then depress the
spindle lock button while turning the sanding disc until
the sanding disc and clamp nut are snug.
5. To remove the wheel, grasp and turn the backing
pad and sanding pad while depressing the spindle
lock button.
Fig. G
Hubbed wheels install directly on the spindle. Thread of
accessory must match thread of spindle.
1. Remove backing flange by pulling away from tool.
2. Thread the wheel on the spindle 1 by hand.
3. Depress the spindle lock button 2 and use a wrench to
tighten the hub of the wheel.
4. Reverse the above procedure to remove the wheel.
NOTICE: Failure to properly seat the wheel before
turning the tool on may result in damage to the tool
or the wheel.
15
16
Mounting Wire Cup Brushes and
Wire Wheels (Fig. A)
WARNING: Failure to properly seat the brush/wheel
could result in serious injury (or damage to the tool
or wheel).
CAUTION: To reduce the risk of personal injury,
wear work gloves when handling wire brushes
and wheels. They can become sharp.
CAUTION: To reduce the risk of damage to the
tool, wheel or brush must not touch guard when
mounted or while in use. Undetectable damage
could occur to the accessory, causing wires to
fragment from accessory wheel or cup.
Wire cup brushes or wire wheels install directly on the
threaded spindle without the use of flanges. Use only wire
brushes or wheels provided with a threaded hub. These
accessories are available at extra cost from your local dealer
or authorised service center.
1. Place the tool on a table, guard up.
2. Thread the wheel on the spindle by hand.
3. Depress spindle lock button 2 and use a wrench on the
hub of the wire wheel or brush to tighten the wheel.
4. To remove the wheel, reverse the above procedure.
NOTICE: To reduce the risk of damage to the tool,
properly seat the wheel hub before turning the tool on.
Mounting Sanding Backing Pads (Fig. G)
DW831
NOTE: Use of a guard with sanding discs that use backing
pads, often called fiber resin discs, is not required. Since a
guard is not required for these accessories, the guard may or
may not fit correctly if used.
WARNING: Failure to properly seat the clamp nut
and/or pad could result in serious injury (or damage
to the tool or wheel).
WARNING: Proper guard must be reinstalled for
grinding wheel, cutting wheel, sanding flap disc,
wire brush or wire wheel applications after sanding
applications are complete.
1. Place or appropriately thread backing pad 17 on
the spindle.
2. Place the sanding disc 16 on the backing pad 17 .
3. While depressing spindle lock button 2 , thread the
sanding clamp nut 15 on spindle, piloting the raised
8
17
Prior to Operation
•
•
•
•
Install the guard and appropriate disc or wheel. Do not
use excessively worn discs or wheels.
Be sure the backing and threaded locking flange are
mounted correctly. Follow the instructions given in the
Accessory Chart.
Make sure the disc or wheel rotates in the direction of
the arrows on the accessory and the tool.
Do not use a damaged accessory. Before each use
inspect the accessory such as abrasive wheels for chips
and cracks, backing pad for cracks, tear or excess wear,
wire brush for loose or cracked wires. If power tool or
accessory is dropped, inspect for damage or install an
undamaged accessory. After inspecting and installing
an accessory, position yourself and bystanders away
from the plane of the rotating accessory and run the
power tool at maximum no-load speed for one minute.
Damaged accessories will normally break apart during
this test time.
OPERATION
WARNING: To reduce the risk of serious personal
injury, turn unit off and disconnect it from
power source before making any adjustments or
removing/installing attachments or accessories.
An accidental start-up can cause injury.
Proper Hand Position (Fig. H)
WARNING: To reduce the risk of serious personal
injury, ALWAYS use proper hand position as shown.
WARNING: To reduce the risk of serious personal
injury, ALWAYS hold securely in anticipation of a
sudden reaction.
English
Fig. I
Proper hand position requires one hand on the side
handle 5 , with the other hand on the body of the tool, as
shown in Figure H.
Fig. H
Angle
3. Maintain an appropriate angle between the tool
and work surface. Refer to the chart according to
particular function.
5
Function
Grinding
Sanding with Flap Disc
Sanding with Backing Pad
Wire Brushing
Switching On and Off (Fig. A)
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 be­fore laying the tool down.
1. To run the tool, press the lock-off button 9 and the
trigger switch 8 .
2. To stop the tool, release the trigger switch.
WARNING: Do not switch the tool On or Off when
under load.
Spindle Lock (Fig. A)
The spindle lock 2 is provided to prevent the spindle from
rotating when installing or removing wheels. Operate the
spindle lock only when the tool is turned off, unplugged
from the power supply, and has come to a complete stop.
NOTICE: To reduce the risk of damage to the tool, do
not engage the spindle lock while the tool is operating.
Damage to the tool will result and attached accessory
may spin off possibly resulting in injury.
To engage the lock, depress the spindle lock button
and rotate the spindle until you are unable to rotate the
spindle further.
Surface Grinding, Sanding and Wire
Brushing (Fig. I)
CAUTION: Always use the correct guard per the
instructions in this manual.
WARNING: Metal dust build-up. Extensive use
of flap discs in metal applications can result in the
increased potential for electric shock. To reduce
this risk, insert an RCD before use and clean the
ventilation slots daily by blowing dry compressed air
into the ventilation slots inaccordance with the below
maintenance instructions.
To perform work on the surface of a workpiece:
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. Material removal rate
is greatest when the tool operates at high speed.
Angle
20˚-30˚
5˚-10˚
5˚-15˚
5˚-10˚
4. Maintain contact between the edge of the wheel and
the work surface.
-- If grinding, sanding with flap discs or wire brushing
move the tool continuously in a forward and
back motion to avoid creating gouges in the
work surface.
-- If sanding with a backing pad, move the tool
constantly in a straight line to prevent burning and
swirling of work surface.
NOTE: Allowing the tool to rest on the work surface without
moving will damage the work piece.
5. Remove the tool from work surface before turning tool
off. Allow the tool to stop rotating before laying it down.
CAUTION: Use extra care when working over an
edge, as a sudden sharp movement of grinder may
be experienced.
Precautions To Take When Working on
a Painted Workpiece
1. Sanding or wire brushing of lead based paint is NOT
RECOMMENDED due to the difficulty of controlling
the contaminated dust. The greatest danger of lead
poisoning is to children and pregnant women.
2. Since it is difficult to identify whether or not a paint
contains lead without a chemical analysis, we
recommend the following precautions when sanding
any paint:
Personal Safety
1. No children or pregnant women should enter the work
area where the paint sanding or wire brushing is being
done until all clean up is completed.
2. A dust mask or respirator should be worn by all persons
entering the work area. The filter should be replaced
daily or whenever the wearer has difficulty breathing.
NOTE: Only those dust masks suitable for working
with lead paint dust and fumes should be used.
Ordinary painting masks do not offer this protection.
See your local hardware dealer for the proper N.I.O.S.H.
approved mask.
3. NO EATING, DRINKING or SMOKING should be done in
the work area to prevent ingesting contaminated paint
9
English
particles. Workers should wash and clean up BEFORE
eating, drinking or smoking. Articles of food, drink, or
smoking should not be left in the work area where dust
would settle on them.
Environmental Safety
1. Paint should be removed in such a manner as to
minimize the amount of dust generated.
2. Areas where paint removal is occurring should be sealed
with plastic sheeting of 4 mils thickness.
3. Sanding should be done in a manner to reduce tracking
of paint dust outside the work area.
Cleaning and Disposal
1. All surfaces in the work area should be vacuumed
and thoroughly cleaned daily for the duration of
the sanding project. Vacuum filter bags should be
changed frequently.
2. Plastic drop cloths should be gathered up and disposed
of along with any dust chips or other removal debris.
They should be placed in sealed refuse receptacles and
disposed of through regular trash pick-up procedures.
During clean up, children and pregnant women should
be kept away from the immediate work area.
3. All toys, washable furniture and utensils used by
children should be washed thoroughly before being
used again.
Edge Grinding and Cutting (Fig. J)
are not designed to withstand side pressures caused
by bending.
Fig. J
5. Remove the tool from the work surface before turning
the tool off. Allow the tool to stop rotating before laying
it down.
MAINTENANCE
Cleaning
WARNING: Do not use edge grinding/cutting wheels
for surface grinding applications because these wheels
are not designed for side pressures encountered
with surface grinding. Wheel breakage and injury
may result.
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.
NOTICE: Edge grinding/cutting with a Type 27 wheel
must be limited to shallow cutting and notching—
less than 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 the Accessories Chart for more information. Edge
grinding/cutting with a Type 41 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/cutting 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
10
WARNING: To reduce the risk of serious personal
injury, turn unit off and disconnect it from
power source before making any adjustments or
removing/installing attachments or accessories.
An accidental start-up can cause injury.
WARNING: Blow dirt and dust out of all air vents with
clean, dry air at least once a week. To minimize the risk
of eye injury, always wear ANSI Z87.1 approved eye
protection when performing this.
WARNING: Never use solvents or other harsh
chemicals for cleaning the non-metallic parts of
the tool. These chemicals may weaken the plastic
materials used in these parts. Use a cloth dampened
only with water and mild soap. Never let any liquid
get inside the tool; never immerse any part of the tool
into a liquid.
Accessories
WARNING: Since accessories, other than those
offered by DeWALT, have not been tested with this
product, use of such accessories with this tool could be
hazardous. To reduce the risk of injury, only DeWALT
recommended accessories should be used with
this product.
WARNING: To assure product SAFETY and
RELIABILITY, repairs, maintenance and adjustment
(including brush inspection and replacement) should
be performed by a DeWALT factory service center
or a DeWALT authorized service center. Always use
identical replacement parts.
English
ACCESSORIES CHART
5" (125 mm) Grinding
Wheels (DW831)
7" (180 mm) Grinding
Wheels (DW840)
Type 27 guard
Type 27 guard
unthreaded backing flange
backing flange
Wire Wheels
Type 27 guard
3" (76.2 mm)
wire cup brush
Type 27
depressed center wheel
Type 27
non-hubbed wheel
threaded locking flange
clamp nut
Type 27 guard
Type 27 guard
Type 27 guard
4" (101.6 mm)
wire wheel
Sanding Flap Discs
Type 27 guard
Type 27 guard
unthreaded backing flange
Type 27 hubbed wheel
Sanding Discs (DW831)
hubbed sanding flap disc
Type 27 hubbed wheel
non-hubbed sanding flap disc
threaded locking flange
rubber backing pad
sanding disc
sanding clamp nut
WARNING: DW840
cannot be used
with conventional
sanding discs and
backing pads due
to mismatched
rated speeds.
CAUTION: Use a Type 27 guard with wire brushes and wheels. Operators and others in the area should wear
appropriate eye, face and body protection. Strands of wire may break and fly off when wire wheels and brushes are
in use.
CAUTION: Type 1 abrasive and diamond cut-off wheels may not be used on this tool. A Type 1 cut-off wheel
guard is not available for these grinders.
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