DeWalt DW870, DW870-220 Instruction Manual

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DEWALT Industrial Tool Company, P.O. Box 158, 626 Hanover Pike, Hampstead, MD 21074 Printed in Korea (SEP97-1) Form No. 383823
DW870/DW870-220 Copyright © 1997

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INSTRUCTION MANUAL
GUIDE D'UTILISATION
MANUAL DE INSTRUCCIONES

DW870/DW870-220
14" (355 mm) Heavy Duty Chop Saw
Scie fendeuse de service intensif de 355 mm (14 po)
Cortadora de metales de 355 mm (14")

INSTRUCTIVO DE OPERACIÓN, CENTROS DE SERVICIO Y PÓLIZA
DE GARANTÍA. ADVERTENCIA: LÉASE ESTE INSTRUCTIVO ANTES
DE USAR EL PRODUCTO.

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IF YOU HAVE ANY QUESTIONS OR COMMENTS ABOUT THIS
OR ANY DEWALT TOOL, CALL US TOLL FREE AT
1-800-4-DEWALT (1-800-433-9258).

IMPORTANT SAFETY INSTRUCTIONS

FOR ALL TOOLS

IMPORTANT: Please make certain that the person who is to
use this equipment carefully reads and understands these
instructions before starting operations.

WARNING: When using electric tools, basic safety precautions
should always be followed to reduce risk of fire, electric shock,
and personal injury, including the following:

READ ALL INSTRUCTIONS

Important Safety Instructions

• KEEP GUARDS IN PLACE and in working order.

• REMOVE ADJUSTING KEYS AND WRENCHES. Form habit of

checking to see that keys and adjusting wrenches are removed
from tool before turning it on.

• KEEP WORK AREA CLEAN. Cluttered areas and benches

invite injuries.

• DON’T USE IN DANGEROUS ENVIRONMENT. Don’t use

power tools in damp or wet locations, or expose them to rain.
Keep work area well lighted.

• KEEP CHILDREN AWAY. All visitors should be kept safe

distance from work area.

• MAKE WORKSHOP KID PROOF with padlocks, master

switches, or by removing starter keys.

• DON’T FORCE TOOL. It will do the job better and safer at the

rate for which it was designed.

• USE RIGHT TOOL. Don’t force tool or attachment to do a job for

which it was not designed.

• USE PROPER EXTENSION CORD. Make sure your extension
cord is in good condition. When using an extension cord, be sure
to use one heavy enough to carry the current your product will
draw. An undersized cord will cause a drop in line voltage
resulting in loss of power and overheating. The following table
shows the correct size to use depending on cord length and
nameplate ampere rating. If in doubt, use the next heavier gage.
The smaller the gage number, the heavier the cord.

Minimum Gage for Cord Sets

Volts Total Length of Cord in Feet

120V 0-25 26-50 51-100 101-150
240V 0-50 51-100 101-200 201-300

Ampere Rating

More Not more AWG
Than 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

• WEAR PROPER APPAREL. Do not wear loose clothing, gloves,
neckties, rings, bracelets, or other jewelry which may get caught
in moving parts. Non-slip footwear is recommended. Wear
protective hair covering to contain long hair.

• ALWAYS USE SAFETY GLASSES. Also use face or dust mask
if cutting operation is dusty. Everyday eyeglasses only have
impact resistant lenses, they are not safety glasses.

• DON’T OVERREACH. Keep proper footing and balance at all
times.

• MAINTAIN TOOLS WITH CARE. Keep tools sharp and clean for
best and safest performance. Follow instructions for lubricating
and changing accessories.

• DISCONNECT TOOLS before servicing; when changing
accessories, such as blades, bits, cutters, and the like.

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• REDUCE THE RISK OF UNINTENTIONAL STARTING. Make
sure switch is in off position before plugging in.

• USE RECOMMENDED ACCESSORIES. Consult the instruction
manual for recommended accessories. The use of improper
accessories may cause risk of injury to persons.

• NEVER STAND ON TOOL. Serious injury could occur if the tool
is tipped or if the cutting tool is unintentionally contacted.

• CHECK DAMAGED PARTS. Before further use of the tool, a
guard or other part that is damaged should be carefully checked

to determine that it will operate properly and perform its intended
function–check for alignment of moving parts, binding of moving
parts, breakage of parts, mounting, and any other conditions that
may affect its operation. A guard or other part that is damaged
should be properly repaired or replaced.

• NEVER LEAVE TOOL RUNNING UNATTENDED. TURN
POWER OFF. Don’t leave tool until it comes to a complete stop.

• REPLACEMENT PARTS. When servicing, use only identical

replacement parts.

Grounding Instructions (DW870-220)

This tool should be grounded while in use to protect the operator
from electric shock. The tool is equipped with a
3-conductor cord and 3-prong grounding type plug to fit the proper
grounding type receptacle. The green (or green and yellow)
conductor in the cord is the grounding wire. Never connect the
green (or green and yellow) wire to a live terminal. If your unit is
intended for use on less than 150 V, it has a plug that looks like
that shown in sketch A. If it is for use on 150 to 250 V, it has a plug
that looks like that shown in sketch D. An adapter, sketches B and
C, is available for connecting sketch A type plugs
to 2-prong receptacles. The green-colored rigid
ear, lug, or the like, extending from the adapter
must be connected to a permanent ground, such
as a properly grounded outlet box. No adapter is

available for a plug as shown in sketch D. ADAPTER SHOWN IN
FIGURES B and C IS NOT FOR USE IN CANADA. Use only 3­wire extension cords that have 3-prong grounding-type plugs and 3­pole receptacles that accept the tool’s plug. Replace or repair
damaged cords.

Additional Safety Rules for Chop Saws

• Always wear safety goggles or other eye protection when using this
tool.

• Before using, inspect each cutting wheel for cracks or flaws. If a
crack or flaw is evident—discard the wheel! The wheel should also
be inspected whenever you think the tool may have been dropped.

• When starting the tool (with a new or replacement wheel installed)
place the tool in a well protected area. If the wheel has an
undetected crack or flaw, it should burst in less than one minute.
Never start the tool with a person in line with the wheel. This
includes the operator.

• In operation, avoid bouncing the wheel or giving it rough treatment.
If this occurs, stop the tool and inspect the wheel.

• Clean your chop saw periodically following the procedure in this
manual.

• Do not remove wheel guard.

• Always use the vise or special fixturing to clamp work.

• Use only wheels rated at 4100 rpm or higher.

• Allow cut off parts to cool before handling.

• Do not attempt to cut wood or plastic with this tool.

AB CD

GROUNDING PIN

GROUNDED

OUTLET

BOX

GROUNDING

MEANS

GROUNDING PIN

ADAPTER

220 VOLT PLUG

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• NEVER CUT MAGNESIUM WITH THIS TOOL.

• Use chop saw in a well-ventilated area.

• Turn chop saw off before removing any pieces from the base.

• DO NOT CUT ELECTRICALLY LIVE MATERIAL.

• NEVER USE A CIRCULAR SAW BLADE IN THIS CHOP SAW.

DO NOT USE TOOTHED BLADES.

• DO NOT OPERATE THIS TOOL NEAR FLAMMABLE LIQUIDS,
GASES OR DUST. Sparks from cutting or motor may ignite dust

and fumes.

SAVE THESE INSTRUCTIONS

Power Supply

Be sure your power supply agrees with the nameplate marking.
120 volts, “60 Hz” means alternating current (normal 120 volt, 60
Hz house current).

A voltage decrease of more than 10% will cause a loss of power and
overheating.

Switch

To start the tool, depress the trigger switch shown in Figure 1. To
turn the tool off, release the switch.

Features and Benefits

• AC/DC permits use with a DC power source such as a welder.

• Switch handle is human engineered for maximum convenience
when the saw is used on a bench, or on the floor.

• Lightweight, sure-grip carrying handle, and fold-down design
combine to make it easy to carry the machine from job to job.

• Rugged steel base with rubber padded feet provide durability
and vibration-free operation for stable cutting.

S

T

O

P

P

E

R

P

I

N

FIG. 1

TRIGGER SWITCH

BLADE LOCK

LEVER

FIG. 2

GEAR

SHAFT

FLANGE,

INSIDE

ABRASIVE WHEEL

ADAPTER

FLANGE, OUTSIDE

WASHER

HEX HEAD BOLT

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• Pivoting fence for convenience and accuracy in making miter
cuts. Right position graduations for 0°, 15°, 30° and 45°. Left
position graduations for 0°, 15° and 30°.

• Blade spindle lock simplifies and speeds blade changing.

• Blade/Fence wrench is conveniently stored in holder at rear of
base.

• Tough steel wheel guard protects operator from the wheel.
Spark guard in base minimizes escaping sparks and protects
surroundings.

• Heavy duty brush system extends brush life.

• High efficiency cooling fan and improved housing design assure
high airflow for cooler operation and long life.

• 8’ power supply cord with separate cord protector is convenient
and simplifies servicing.

• 100% ball and roller bearing construction for longer tool life.

Removal and Installation of Wheels

1. Be sure tool is disconnected from power supply.

2. Push in blade lock lever (Fig. 1) and rotate wheel by hand until
blade lock lever engages slot in inside flange to lock wheel.
Loosen the hex head bolt in the center of the abrasive wheel
with the wrench provided at rear of base. Bolt has right hand
thread.

3. Remove the bolt, washer, outside flange, adapter, and old
wheel (Fig. 2).

4. Install the new abrasive wheel by reversing the above steps.
Make sure adapter is on gear shaft and centered in wheel.

5. Do not overtighten bolt.

WARNING: Check the work surface that the chop saw rests on
when replacing with a new abrasive wheel. It is possible that the
wheel may contact the work surface (through the base) when the
arm is fully lowered.

DO NOT MAKE ANY ADJUSTMENTS WHILE WHEEL IS IN
MOTION. DO NOT MAKE ANY ADJUSTMENTS WHILE CHOP
SAW IS PLUGGED INTO POWER SUPPLY.

Quick Release Vise

Your saw features a quick release vise for greater convenience. To
release the vise, turn the crank handle a turn or two
counterclockwise to release the pressure on the vise jaw. With the
crank loose, lift the release lever on top of the moveable jaw, as
shown in Figure 3. Hold the lever up as you pull back on the crank
and open the jaws. When clamping an object, you need only to
push in the crank handle to the desired position. The moveable jaw
will slide freely until contact is made with the workpiece. Turn the
crank clockwise to clamp the workpiece in place.

To Adjust Vise Stop

CUTTING ANGLE

Use the wrench to loosen the two hex bolts (Fig. 3). (Do not
remove the bolts). The fence can be rotated in either direction.
Securely tighten both the bolts before use.

30

15

FIG. 3

WRENCH

FENCE

FENCE

BOLTS

VISE

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FIG. 4

30

15

1

5

0

4

5

30

FIG. 5

30

15

15

0

45

30

INDEX LINE

FIG. 6

FIG. 7

0.3"

7.62 mm

BRUSH

WEAR LINE

OPENING ADJUSTMENT

Remove both fence bolts. Move fence forward or backward to
desired location. Install both bolts. Tighten both bolts.

To Carry

Fold down unit to position where you can attach chain to pin on tool
arm (Fig. 4).

Cutting Capacity

The wide vise opening and high pivot point provide cutting capacity
for many large pieces. Use this chart to determine total maximum
size of cuts that can be made with a new wheel. Recommended
applications are: metal studs, electrical conduit up to 4" diameter,
bar stock and reinforcing bar up to 3/4" diameter.

NOTE: As cutting width increases, cutting height decreases.

CAUTION: CERTAIN LARGE , CIRCULAR OR IRREG­ULARLY SHAPED OBJECTS MAY REQUIRE ADDITIONAL
HOLDING MEANS.

CAUTION: DO NOT CUT MAGNESIUM WITH THIS TOOL.

Maximum Cutting Depth

To obtain maximum cutting depth, move the fence to the rear
position (Fig. 5).

NOTE: A new wheel, when pushed all the way down, will extend
below the base and cut into the work surface.

Degree Setting

Align the index line stamped in the base with the appropriate
degree for the desired angle of cut (Fig. 6). For very accurate cuts,
use a protractor.

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