Ingersoll-Rand ARO 8421-A4-W User manual

OPERATOR’S MANUAL
INCLUDING:ĂOPERATION,ĂINSTALLATIONĂ&ĂMAINTENANCE Released: 08-31-90
Re ised: 09-01-00
Form: ă3709-2
E2000 INGERSOLL–RAND COMPANY DPRINTED IN U.S.A.
Ingersoll–Rand Company
1725 U.S. No. 1 North DP.O. Box 8000 DSouthern Pines, NC 28388–8000
ARO Tool Products
For parts and service information, contact your local ARO distributor, or the Customer Service Dept. of the Ingersoll–Rand
Distribution Center, White House, TN at PH: (615) 672–0321, FAX: [phone].
MODELS 8421–A4–W
ROTARY SANDERS
ARO is not responsible for customer modification of tools for applications on which ARO
was not consulted.
IMPORTANT SAFETY INFORMATION ENCLOSED.
READ THIS MANUAL BEFORE OPERATING TOOL.
IT IS THE RESPONSIBILITY OF THE EMPLOYER TO PLACE THE INFORMATION
IN THIS MANUAL INTO THE HANDS OF THE OPERATOR.
FAILURE TO OBSERVE THE FOLLOWING WARNINGS COULD RESULT IN INJURY.
PLACING TOOL IN SERVICE
•Always operate, inspect and maintain this tool
in accordance with American National
Standards Institute Safety Code for Portable
Air Tools (ANSI B186.1).
•For safety, top performance, and maximum
durability of parts, operate this tool at 90 psig
(6.2 bar/620 kPa) maximum air pressure at the
inlet with 5/16” (8 mm) inside diameter air
supply hose.
•Always turn off the air supply and disconnect
the air supply hose before installing, removing
or adjusting any accessory on this tool, or
before performing any maintenance on this
tool.
•Do not use damaged, frayed or deteriorated
air hoses and fittings.
•Be sure all hoses and fittings are the correct
size and are tightly secured. See Dwg.
TPD905–1 for a typical piping arrangement.
•Always use clean, dry air at 90 (6.2 bar/
620 kPa) psig maximum air pressure. Dust,
corrosive fumes and/or excessive moisture
can ruin the motor of an air tool.
•Do not lubricate tools with flammable or
volatile liquids such as kerosene, diesel or jet
fuel.
•Do not remove any labels. Replace any
damaged label.
USING THE TOOL
•Always wear eye protection when operating or
performing maintenance on this tool.
•Always wear hearing protection when
operating this tool.
•Keep hands, loose clothing and long hair
away from rotating end of tool.
•Anticipate and be alert for sudden changes in
motion during start up and operation of any
power tool.
•Keep body stance balanced and firm. Do not
overreach when operating this tool. High
reaction torques can occur at or below the
recommended air pressure.
•Tool accessories may continue to rotate
briefly after throttle is released.
•Air powered tools can vibrate in use.
Vibration, repetitive motions or uncomfortable
positions may be harmful to your hands and
arms. Stop using any tool if discomfort,
tingling feeling or pain occurs. Seek medical
advice before resuming use.
•Use accessories recommended by ARO.
•This tool is not designed for working in
explosive atmospheres.
•This tool is not insulated against electric
shock.
The use of other than genuine ARO replacement parts may result in safety hazards, decreased tool
performance, and increased maintenance, and may invalidate all warranties.
Repairs should be made only by authorized trained personnel. Consult your nearest ARO Authorized
Servicenter.

2
WARNING LABEL IDENTIFICATION
FAILURE TO OBSERVE THE FOLLOWING WARNINGS COULD RESULT IN INJURY.
Always wear eye protection
when operating or perform-
ing maintenance on this
tool.
WARNING WARNING
Always wear hearing
protection when operating
this tool.
Always turn off the air sup-
ply and disconnect the air
supply hose before install-
ing, removing or adjusting
any accessory on this tool,
or before performing any
maintenance on this tool.
WARNING
Air powered tools can vibrate
in use. Vibration, repetitive
motions or uncomfortable po-
sitions may be harmful to your
hands and arms. Stop using
any tool if discomfort, tingling
feeling or pain occurs. Seek
medical advice before resum-
ing use.
WARNING
Do not carry the tool by
the hose.
WARNING WARNING
Do not use damaged, frayed
or deteriorated air hoses
and fittings.
WARNING
Keep body stance balanced
and firm. Do not overreach
when operating this tool.
WARNING
Operate at 90 psig (6.2 bar/
620 kPa) Maximum air pressure.
90 psig
(6.2bar/620kPa)
SANDER SPECIFIC WARNINGS
•Use only a sanding pad, buffing wheel or
polishing bonnet with these tools. Do not use
any grinding wheel, bur or metal removing
accessory other than a sanding pad with
these tools. Never use an accessory having a
maximum operating speed less than the free
speed of the Sander in which it is being used.
•These Sanders will operate at the free speed
specified on the nameplate if the air supply
line furnishes 90 psig (6.2 bar/620 kPa) air
pressure at the tool. Operation at higher air
pressure will result in excessive speed.
•Do not operate this Sander away from the
work surface.
•Check for excessive speed and vibration
before operating.
•Do not use this tool if actual free speed
exceeds the nameplate rpm.
•Never exceed the rated rpm of tool.
•Repeated prolonged operator exposure to
vibrations which may be generated in the use
of certain hand–held tools may produce
Raynaud’s phenomenon, commonly referred
to as Whitefinger disease. The phenomenon
produces numbness and burning sensations
in the hand and may cause circulation and
nerve damage as well as tissue necrosis.
Repetitive users of hand–held tool who
experience vibrations should closely monitor
duration of use and their physical condition.
•When using a pad having a shank, insert the
shank to full depth in the collet. When using a
pad on a threaded arbor, make certain the
flange nut is tightened securely. Check the
tightness of the collet nut or flange nut before
operating a Sander to make certain it will not
loosen during operation.
•Do not operate a Belt Sander with the Cover
removed.

3
LUBRICATION
Where Used ARO Part # Description
‘‘O”Rings & Lip Seals 36460 4 oz. Stringy
Lubricant
Gears and Bearings 33153 5 lb. ‘‘EP”–NLGI
#1 Grease
Always use an air line lubricator with these tools.
We recommend the following Filter–Lubricator–
Regulator Unit:
ARO Model P29231–110
EVERY 160 HOURS OF TOOL OPERATION –Flush tool with
a solution of equal parts cleaning solvent and spindle oil.
Do not mark any nonmetallic surface on this tool
with customer identification codes. Such actions
could affect tool performance.
MAIN LINES 3 TIMES
AIR TOOL INLET SIZE
TO
AIR
SYSTEM
TO
AIR
TOOL
LUBRICATOR
REGULATOR FILTER
BRANCH LINE 2 TIMES
AIR TOOL INLET SIZE
DRAIN REGULARLY COMPRESSOR
(Dwg. TPD905–1)

3
2
6
1
10
20
4
12
8
11 17
21
14
5
9
7
INSTALL RETAINING RING (21) AS SHOWN
(BOWED AWAY FROM BEARING).
19
13
1615
18
22
23
24
25
26
28
22
23
29
27
30
31
32
FACE WITH ROUNDED O.D. ON THIS SIDE
(ATP–562)
4

PART NUMBER FOR ORDERING PART NUMBER FOR ORDERING
5
1 Housing 48064. . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 Roll Pin Y178–33. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 Lever 48067. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 Muffler 48171–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5 Seat 48071. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 Tip Valve 48070. . . . . . . . . . . . . . . . . . . . . . . . . . .
7 Spring 32858. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8‘‘O”Ring Y325–14. . . . . . . . . . . . . . . . . . . . . . . . . . . .
9 Inlet Adapter 48829–1. . . . . . . . . . . . . . . . . . . . . . . .
10 Valve Stem 48065. . . . . . . . . . . . . . . . . . . . . . . . . .
11 Regulator 48068. . . . . . . . . . . . . . . . . . . . . . . . . . .
12 ‘‘O”Ring Y325–13. . . . . . . . . . . . . . . . . . . . . . . . . . . .
13 Retaining Ring Y147–62. . . . . . . . . . . . . . . . . . . . . . .
14 Bracket 48832–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15 Ball Valve 104077–1. . . . . . . . . . . . . . . . . . . . . . . . . . .
16 Adapter 6045. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17 Barbed Insert 30764. . . . . . . . . . . . . . . . . . . . . . . .
18 Elbow Y229–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19 Tube 48830–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20 Roll Pin Y178–47. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21 Retaining Ring 44533. . . . . . . . . . . . . . . . . . . . . . .
22 Bearing (2 req’d) 48169–1. . . . . . . . . . . . . . . . . . . . .
23 End Plate (2 req’d) 44529. . . . . . . . . . . . . . . . . . .
24 Cylinder 44531. . . . . . . . . . . . . . . . . . . . . . . . . . . .
25 Blade (5 req’d) 44538. . . . . . . . . . . . . . . . . . . . . . .
26 Rotor 44532–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
27 Spacer 44878. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28 Key 39442. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29 Spindle 48828–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30 Guard 48831–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31 ‘‘O”Ring Y325–36. . . . . . . . . . . . . . . . . . . . . . . . . . . .
32 Lock Ring 44536. . . . . . . . . . . . . . . . . . . . . . . . . . .
33 Sleeve (not shown) 48073. . . . . . . . . . . . . . . . . . .
DISASSEMBLY/ASSEMBLY INSTRUCTIONS
Always wear eye protection when operating or performing
maintenance on this tool.
Always turn off the air supply and disconnect the air
supply hose before installing, removing or adjusting any
accessory on this tool or before performing any mainte-
nance on this tool.
•Never apply excessive pressure by a holding device which
may cause distortion of a part.
•Apply pressure evenly to parts which have a press fit.
•Apply even pressure to the bearing race that will be press
fitted to the mating part.
•Use correct tools and fixtures when servicing this tool.
•Don’t damage ‘‘O”rings when servicing this tool.
•Use only genuine ARO replacement parts for this tool. When
ordering, specify part number, description, tool model number
and serial number.
MOTOR DISASSEMBLY
–Remove sanding pad.
–Remove inlet adapter (9), releasing bracket (14) and compo-
nents from tool.
–Remove lock ring (32) –LEFT HAND THREADS –‘‘O”ring
(31) and guard (30).
–Remove motor assembly and pin (20). NOTE: It may be nec-
essary to tap housing with a soft face hammer to loosen motor
from housing.
–Remove retaining ring (21).
–Using special brass blocks to fit around o.d. of cylinder, clamp
around cylinder and press shaft of spindle (29) thru bearing
(22) and end plate (23).
–Remove blades (25), rotor (26) and key (28).
–Remove other bearing (22) and end plate (23).
MOTOR ASSEMBLY
–Assemble bearings (22) into end plates (23), pressing on out-
er race of bearings.
–Press one end plate (23), with bearing (22), on shaft of spindle
(29).
–Install key (28) in key slot.
–Assemble rotor (26) to spindle, aligning keyway with key (28).
–Assemble five rotor blades (25) to rotor slots –straight side
out.
–Assemble cylinder (24) over rotor.
–Assemble other end plate (23), with bearing (22), to shaft of
spindle, pressing on inner race of bearing.
–Install retaining ring (21) to groove in spindle, with bow of ring
positioned as shown on parts illustration page.
–Align notches in end plates and cylinder and install roll pin (20)
to notches.
–Assemble motor to housing, aligning pin (20) with groove in
housing.
–Assemble spacer (27) to housing.
–Grease and assemble ‘‘O”ring (31) to lock ring (32).
–Assemble guard (30) over lock ring (32) and thread lock ring
into housing –LEFT HAND THREADS. Tighten securely.
–Assemble bracket (14) and components to tool, inserting tube
(19) thru hole in guard (30).
–Secure bracket with inlet adapter (9).
THROTTLE DISASSEMBLY
–Remove muffler (4).
–Remove inlet adapter (9), releasing bracket (14), ‘‘O”ring (8),
spring (7) and valve (6). NOTE: Do not remove seat (5) unless
damage is evident.
–Remove lock ring (32) –LEFT HAND THREADS –‘‘O”ring
(31) and guard (30).
–Remove retaining ring (13), releasing regulator (11) with ‘‘O”
ring (12) and valve stem (10).
–To remove lever (3), remove roll pin (2).
–Do not disassemble components from bracket (14) unless
damage is evident. To remove ball valve (15), unthread adapt-
er (16) and elbow (18) from ball valve (15). Remove screw and
plastic knob from ball valve to release valve.
–Loosen nut on elbow (18) to remove tube (19).

6
THROTTLE ASSEMBLY
–Assemble ball valve to bracket (14) and assemble plastic
knob to ball valve, securing with screw.
–Assemble adapter (16) thru side of bracket and thread into ball
valve (15).
–Assemble insert (17) to adapter (16).
–Assemble elbow (18) thru side of bracket and thread into ball
valve (15).
–Assemble tube (19) into elbow and tighten nut on elbow to se-
cure.
–Assemble inlet adapter (9) to bracket and assemble ‘‘O”ring
(8) to inlet adapter.
–Grease and assemble ‘‘O”ring (12) to regulator (11).
–Assemble valve stem (10) to housing, with hole in valve stem
in line with housing to accept valve (6).
–Assemble seat (5) to housing with rounded corners into hous-
ing first.
–Coat valve (6) with ARO 29665 spindle oil and assemble to
housing, securing valve stem (10).
–Assemble regulator (11) to housing, securing with retaining
ring (13).
–Assemble guard (30) and lock ring (32) to tool –LEFT HAND
THREADS.
–Assemble spring (7) to housing.
–Assemble bracket (14) to housing, inserting tube (19) thru
hole in guard (30) and thread inlet adapter (9) to housing, se-
curing bracket (14).
–Assemble muffler (4) to housing.

7

PN 49999–103