Dynabrade 51820 User manual

Always operate, inspect and maintain this tool in accordance with the Safety Code for portable air tools
(ANSI B186.1) and any other applicable safety codes and regulations. Please refer to Dynabrade’s
Warning/Safety Operating Instructions for more complete safety information.
Air Motor and Machine Parts
Parts Page Reorder No. PD00•21
Effective February, 2000
.4 Hp/Right-Angle/Front Exhaust
2" Disc Sander
Index Key
No. Part # Description
150110 2" Disc Pad - 1/4" - 20
250109 2" Disc Pad - 3/8" - 24
302029 1/4" -20 Spindle
02028 3/8" -24 Spindle
402035 Lock Nut
501486 Silencer
654520 Bearing
797116 Shim
897117 Shim
997118 Shim
10 02623 Gear - 12,000 RPM
02597 Gear - 15,000 RPM
02599 Gear - 20,000 RPM
11 02042 Wick - 12,000 RPM
02044 Wick - 15 & 20,000 RPM
12 02043 Wick - 12,000 RPM
02045 Wick - 15 & 20,000 RPM
13 02052 Housing – Includes:
13A01041 Gear Oil Fitting
13B02041 Gear Oil Plate
13C02033 Needle Bearing
14 02624 Pinion - 12,000 RPM
02598 Pinion - 15,000 RPM
02600 Pinion - 20,000 RPM
15 01728 Felt Silencer
16 01461 Lock Nut
17 02697 Bearing
18 54543 Shim
19 54544 Shim
20 54551 Shim
21 01478 Bearing Plate
22 50767 PIn (2)
23 01479 Spacer
24 02037 Rotor
25 01480 Blade (4/pkg.)
26 01476 Cylinder
27 02676 Bearing Plate
28 02696 Bearing
29 02679 Shield
30 01547 Collar
31 53902 Housing - 51820
53903 Housing - 51821
53904 Housing - 51822
53905 Housing - 51823
53906 Housing - 51824
53907 Housing - 51825
32 12132 Pin
33 01449 Valve Stem
34 01448 Throttle Lever
01462 Safety Lock Lever
35 01464 Seal
36 01472 Tip Valve
37 01468 Spring
38 95558 Retaining Ring
39 95730 O-Ring
40 01469 Speed RegulatorAssy.
41 01024 O-Ring
42 96065 O-Ring
43 53190 Block Plate
44 01494 Inlet Bushing
WARNING
!
Models:
51820 – 12,000 RPM, 1/4"-20
51821 – 15,000 RPM, 1/4"-20
51822 – 20,000 RPM, 1/4"-20
51823 – 12,000 RPM, 3/8"-20
51824 – 15,000 RPM, 3/8"-20
51825 – 20,000 RPM, 3/8"-20
A8
3
5
7
9
4
6
8
11
10
12
14
16 17
15 18 19 22
20 21
23
24
26
25
22 27
28
29
30
31
32
34
33
35 37
36
38
40
39
41
A8
O1
A4
W1
W1
13
13C
13B
13A
17 N•m
T
34 N•m
T
42
O1
A8
43
44
23 N•m
T
23 N•m
T
For Serial No. 0B1000 and Higher
Loctite: A4= Loctite #680
A8= Loctite #567
Torque: N•m x 8.85 = In. - lbs.
Oil: O1=Air Lube
WWicking: W1= Gear Oil
O
A
T
KEY
2
1
Left Hand Threads
Right Hand Threads

2
OneYearWarranty
Following the reasonable assumption that any inherent defect which might prevail in a product will become apparent to the user within one year from the date
of purchase, all equipment of our manufacture is warranted against defects in workmanship and materials under normal use and service. We shall repair or
replace at our factory, any equipment or part thereof which shall, within one year after delivery to the original purchaser, indicate upon our examination to
have been defective. Our obligation is contingent upon proper use of Dynabrade tools in accordance with factory recommendations, instructions and safety
practices. It shall not apply to equipment which has been subject to misuse, negligence, accident or tampering in any way so as to affect its normal
performance. Normally wearable parts such as bearings, contact wheels, rotor blades, etc., are not covered under this warranty.
Important Operating, Maintenance and Safety Instructions
Carefully read all instructions before operating or servicing any Dynabrade®Abrasive Power Tool.
Warning: Hand, wrist and arm injury may result from repetitive work motion and overexposure to vibration.
Important: All Dynabrade Rotary Vane air tools must be used with a Filter-Regulator-Lubricator to maintain all warranties.
Operating Instructions:
Warning: Eye, face, respiratory, sound and body protection must be worn while operating power tools. Failure to do so may result in serious injury or death.
Follow safety procedures posted in workplace.
1. With power source disconnected from tool, securely fasten abrasive/accessory on tool.
2. Install air fitting into inlet bushing of tool. Important: Secure inlet bushing of tool with a wrench before attempting to install the air fitting to avoid
damaging valve body housing.
3. Connect power source to tool. Be careful not to depress throttle lever in the process.
4. Check tool speed with tachometer. If tool is operating at a higher speed than the RPM marked on the tool or operating improperly, the tool should be
serviced to correct the cause before use.
Maintenance Instructions:
1. Check tool speed regularly with a tachometer. If tool is operating at a higher speed than the RPM marked on the tool, the tool should be serviced to
correct the cause before use.
2. Some silencers on air tools may clog with use. Clean and replace as required.
3. All Dynabrade Rotary Vane air motors should be lubricated. Dynabrade recommends one drop of air lube per minute for each 10 SCFM (example: if the
tool specifications state 40 SCFM, set the drip rate of your filter-lubricator at 4 drops per minute).
DynabradeAir Lube (P/N 95842: 1 pt. 473 ml.) is recommended.
4. AnAir Line Filter-Regulator-Lubricator must be used with this air tool to maintain all warranties. Dynabrade recommends the following: 11405 Air Line
Filter-Regulator-Lubricator — Provides accurate air pressure regulation, two-stage filtration of water contaminants and micro-mist lubrication of pneumatic
components. Operates up to 40 SCFM @ 100 PSIG has 3/8" NPT female ports.
5. Lubricate wick system through angle gear head gear oil fitting with 2-3 plunges every 8 hours of use for maximum gear life. Important: Use
recommended angle gear oil only for wick system.
Do not contaminate wick with any other oil or grease product (Order 95848 Gear Oil and 95541 Gun).
6. Use only genuine Dynabrade replacement parts. To reorder replacement parts, specify the Model #, Serial # and RPM of your machine.
7. AMotor Tune-Up Kit (P/N 96179) is available which includes assorted parts to help maintain motor in peek operating condition. Please refer to
Dynabrade’s Preventative Maintenance Schedule for a guide to expectant life of component parts.
8. Mineral spirits are recommended when cleaning the tool and parts. Do not clean tool or parts with any solvents or oils containing acids, esters, keytones,
chlorinated hydrocarbons or nitro carbons.
•Important: User of tool is responsible for following accepted safety codes such as those published by theAmerican National Standards Institute (ANSI).
•Operate machine for one minute before application to workpiece to determine if machine is working properly and safely before work begins.
•Always disconnect power supply before changing abrasive/accessory or making machine adjustments.
•Inspect abrasives/accessories for damage or defects prior to installation on tools.
•Please refer to Dynabrade’s Warning/Safety Operating Instructions Tag (Reorder No. 95903) for more complete safety information.
•Warning: Hand, wrist and arm injury may result from repetitive work, motion and overexposure to vibration.
Notice
All Dynabrade motors use the highest quality parts and metals available and are machined to exacting tolerances. The failure of quality pneumatic motors can most
often be traced to an unclean air supply or the lack of lubrication. Air pressure easily forces dirt or water contained in the air supply into motor bearings causing early
failure. It often scores the cylinder walls and the rotor blades resulting in limited efficiency and power. Our warranty obligation is contingent upon proper use of our
tools and cannot apply to equipment which has been subjected to misuse such as unclean air, wet air or a lack of lubrication during the use of this tool.
Safety Instructions:
Products offered by Dynabrade should not be converted or otherwise altered
from original design without expressed written consent from Dynabrade, Inc.
Model Motor Motor Sound Air Flow Rate Air Pressure Spindle Weight Length Height
Number HP (W) RPM Level CFM/SCFM (LPM) PSIG (Bars) Thread Pound (kg) Inch (mm) Inch (mm)
All Models .4 (298) 12,000-20,000 85 dB(A) 3/21 (595) 90 (6.2) 1/4"-20or3/8"-24male 1.1 (.5) 5 (134) 3-1/4 (83)
Additional Specifications: Air Inlet Thread 1/4" NPT • Hose I.D. Size 1/4" (8 mm)

Disassembly/Assembly Instructions - Right-Angle Tools
Important: Manufacturer’s warranty is void if tool is disassembled before warranty expires.
Please refer to parts breakdown for part identification.
Gear Casing Disassembly:
Important: Inlet adapter must be secured before attempting to remove air fitting to avoid damaging composite motor housing.
1. Secure motor housing in vise using 52296 Repair Collar or padded jaws, so that 02052 Right-Angle Head Housing is facing up.
2. Using an adjustable pin wrench turn 02035 Lock Nut counter-clockwise.
3. Remove spindle from 02052 Housing.
4. Using a screw driver, pick wicks (2) out from housing (Note: Wick may already be removed with the spindle.)
5. Using a 34mm crows foot wrench, remove 01461 Lock Nut by turning counter-clockwise.
6. Place 02052 Housing in an arbor press with spindle opening facing down.
7. Using a 9mm drift pin press out 02041 Gear Oil Plate and 02033 Bearing (located on the top of the 02052 Housing).
Motor Disassembly:
1. Remove tool from vise.
2. Pull motor assembly from housing assembly.
3. Disassemble motor assembly by pressing 02037 Rotor from 02696 Rear Bearing. Press 02696 Bearing out of 02676 Rear Bearing Plate.
4. Remove 01476 Cylinder and 01480 Blades.
5. Place 02037 Rotor in a vise with soft jaws and unscrew pinion using a counter-clockwise direction.
6. Slip 01478 Front Bearing Plate off of 02037 Rotor.
7. Remove 01479 Spacer from 02037 Rotor.
8. Remove 02697 Bearing from 01478 Front Bearing Plate.
9. Remove shims from 01478 Front Bearing Plate.
Valve Body Disassembly:
1. Secure motor housing in 52296 Repair Collar or padded jaws with motor opening facing down.
2. Unscrew inlet adapter turning counter-clockwise.
3. Using needle nose pliers, remove 01468 Spring, 01472 Tip Valve, and 01464 Seal.
4. Resecure housing in vise making sure throttle lever 01448 Throttle Lever and 12132 Pin are accessible.
5. Using a 2.5mm diameter drift pin and hammer, tap 12132 Pin until it falls out of the housing and remove throttle lever.
6. Remove from vise.
7. Remove 95558 Retaining Ring using retaining ring pliers.
8. Push 01469 Speed Regulator from housing.
Gear Casing Assembly:
1. Press 01041 Gear Oil Fitting into 02041 Gear Oil Plate with 01041 Gear Oil Fitting Head
recessed into 02041 Gear Oil Plate.
2. Place 2 drops of #680 Loctite®(or equivalent) at location below.
3. Place 02041 Gear Oil Plate into 02052 Housing as shown.
4. Press 02033 Needle Bearing into 02052 Housing as shown.
Motor Assembly:
Important: Make sure parts have been cleaned and thoroughly inspected for wear and
damage before assembling.
1. Place 02037 Rotor in soft jaw vise with threaded spindle facing upward.
2. Slip 01479 Spacer onto 02037 Rotor.
3. Place a .002" Shim into 01478 Front Bearing Plate as an initial spacing then slip 02697 Bearing
into 01478 Front bearing Plate. Slip assembly onto 02037 Rotor. Tighten pinion onto rotor torque 17 N•m/150 in.-lbs.
4. Check clearance between rotor and bearing plate by using a .001" feeler gauge. Clearance should be at .001" to .0015". Adjust clearance by repeating
steps 1-3 with different shim if necessary.
5. Once proper rotor gap clearance is achieved, install well lubricated 01480 Blades into 02037 Rotor (use 95842 DynabradeAIr Lube or equivalent).
6. Install 01476 Cylinder so it rests against the 01478 Bearing Plate (making sure inlet holes of cylinder are in alignment with inlet holes in 02676
Rear Bearing Plate).
7. Press 02696 Bearing into 02676 Rear Bearing Plate. Press these parts onto 02037 Rotor. Important: Fit must be snug between bearing plates and
cylinder. If too tight, rotor will not turn freely. Rotor must then be lightly tapped at press fit end so it will turn freely while still maintaining a snug fit. A
loose fit will not achieve the proper preload of motor bearings.
8. Secure housing in vise using 52296 Repair Collar or padded jaws so that motor cavity faces upward.
9. Install motor assembly in housing, make sure motor drops all the way into housing. (Note: Align the nodes in side of housing.)
10. Slip 01547 Insulator Collar over 01461 Lock Nut. (continued on next page)
3
02052 Housing 02033 Needle Bearing
02041 Gear Oil Plate
2 Drops of Loctite®
01041 Gear Oil Fitting

Disassembly/Assembly Instructions - (continued)
11. Apply Loctite®#567 to threads, and screw 01461 Lock Nut (left-hand threads), onto 02052 Housing.
12. Thread 02052 Housing and 01461 Lock NutAssembly onto motor housing assembly (right-hand threads), drawing the two assemblies together.
13. Adjust orientation of throttle lever to agree with your grip and comfort level allowing for additional rotation due to tightening to set torque.
14. Using a 34mm crow foot and a torque wrench set at (34 N•m/300 in. - lbs.), secure the gear case housing and lock nut in place.
15. Press 54520 Bearing and then gear onto spindle shaft, making sure drive hexes are aligned.
16. Place 01486 Silencer over spindle shaft at threaded end.
17. Slip bottom wick over spindle shaft, then place top wick over spindle shaft.
18. Insert spindle shaft assembly into 02052 Housing.
19. Torque 02035 Lock Nut to 23 N•m/200 in. - lbs.
20. Shim spindle assembly using shims if required.
Note: When assembling angle-head assembly onto the motor housing, make sure flats on the wicks are both facing the pinion or tool will not run.
Tool Assembly is complete. Please allow 30 minutes for adhesives to cure before operating tool.
Important: Before operating, place 2-3 drops of Dynabrade Air Lube (P/N 95842) directly into air inlet with throttle lever depressed. Operate tool for
30 seconds to determine if tool is operating properly and to allow lubricating oils to properly penetrate motor. Motor should now be tested for proper operation at
90 PSIG. If motor does not operate properly or operates at a higher RPM than marked on the tool, the tool should be serviced to correct the cause before use.
Loctite®is a registered trademark of Loctite Corp.
DYNABRADE®
DYNABRADE, INC., 8989 Sheridan Drive •Clarence, NY 14031-1490 •Phone: [phone] •Fax: [phone] •International Fax: [phone]
DYNABRADE EUROPE S.àr.l., ZoneArtisanale •L-5485 Wormeldange—Haut, Luxembourg •Telephone: [phone] •Fax: [phone]
©DYNABRADE, INC., 2000 PRINTED IN USA
Visit Our Web Site: www.Dynabrade.com Email: Customer.Service@Dynabrade
Optional Accessories
DynabradeAir Lube
•Formulated for pneumatic equipment.
•Absorbs up to 10% of its weight in water.
•Prevents rust and formation of sludge.
•Keeps pneumatic tools operating longer
with greater power and less down time.
95842: 1pt. (473 ml)
95843: 1gal. (3.8L)
96179 Motor Tune-Up Kit
•Includes assorted parts to help
maintain and repair motor.
DynabradeAngle Gear Oil
•Specifically formulated to saturate wick system in right
angle gear head.
•Easy to apply using Dynabrade P/N 95541 Oil Gun.
Apply 3 plunges every 8 hours of operation into tools
lubrication fitting.
95848: 2 oz. tube
95849: 10 oz. tube
52296 Repair Collar
•Specially designed collar for use in vise to prevent damage
to valve body of tool during disassembly/assembly
Dynaswivel®
•Swivels 360° at two locations which allows an
air hose to drop straight to the floor, no matter
how the tool is held.
94300 1/4" NPT
Apply 3 plunges
into lubrication
fitting every
8 hours of
operation.
Expect a
gear life of
500 hours
minimum,
with proper
lubrication.