MIRKA Random Orbital Sander, MR-508, MR-608, MR-508V, MR-608V Operating Instructions Manual

Random Orbital Sander

125 mm (5 in.) & 150 mm (6 in.)

Operating Instructions

Random Orbital Sander

MIRKA®

125 mm (5 in.) & 150 mm (6 in.)

2

MIRKA 12,000 RPM
125 mm (5 in.) & 150 mm (6 in.)
RANDOM ORBITAL SANDERS

The warranty terms are as follows:

- 12 months on KWH MIRKA air tools.

- 3 months on tool parts repaired by KWH MIRKA.

The warranty period commences at the date of purchase. The warranty only covers imputable material and manu­facturing defects.

Parts replacement or repair during the warranty period is free of charge if carried out by an ofcial KWH MIRKA

service center.

Freight costs are always to be paid by the purchaser.

The warranty does not include normal wear and tear, overloading or improper use. The warranty only covers the
local repair, not the tool replacement.

Compensation for downtime and loss of production are explicitly not included in the warranty.

Repair claims under warranty will only be honored if the tool is returned in its original assembled state. Any disas­sembly will void the warranty.

The warranty can only be submitted to the dealers where the tool was purchased.

Warranty

1

1) General Industry Safety & Health Regulations, Part 1910,
OSHA 2206, available from: Superintendent of Documents;

Government Printing Ofce; Washington DC 20402

2) Safety Code for Portable Air Tools, ANSI B186.1 available from:

American National Standards Institute, Inc.; 1430 Broadway;

New York, New York 10018

3) State and Local Regulations.

This sander is designed for sanding all types of materials i.e.
metals, wood, stone, plastics, etc. using abrasive designed for this
purpose. Do not use this sander for any other purpose than that
specied without consulting the manufacturer or the manufac­turer’s authorized supplier. Do not use back-up pads that have a
working speed less than 12,000 RPM free speed.

The tool is intended to be operated as a hand held tool. It is
always recommended that the tool be used when standing on a

solid oor. It can be in any position but before any such use, the
operator must be in a secure position having a rm grip and foot-

ing and be aware that the sander can develop a torque reaction.
See the section “Operating Instructions”.

Closed Loop Pipe System

Sloped in the direction of air flow

Drain Leg

Ball Valve

To Tool Station

Filter

Drain Valve

Regulator

Lubricator

Ball

Valve

Ball Valve

Air Flow

Air Dryer

Air Compressor

and Tank

Air Hose

To Coupler

at or near Tool

Please Read and Comply with

Putting the Tool into Service

Operating Instructions

Use a clean lubricated air supply that will give a measured air
pressure at the tool of 6.2 bar (90 psig) bar when the tool is run­ning with the lever fully depressed. It is recommended to use an
approved 10 mm (3/8 in.) x 8 m (25 ft) maximum length airline. It
is recommended that the tool be connected to the air supply as
shown in Figure 1.

Do not connect the tool to the airline system without incorporating
an easy to reach and operate air shut off valve. The air supply

should be lubricated. It is strongly recommended that an air lter,

regulator and lubricator (FRL) be used as shown in Figure 1 as
this will supply clean, lubricated air at the correct pressure to
the tool. Details of such equipment can be obtained from your
supplier. If such equipment is not used then the tool should be
manually lubricated

To manually lubricate the tool, disconnect the airline and put 2 to
3 drops of suitable pneumatic motor lubricating oil such as Fuji
Kosan FK-20, Mobil ALMO 525 or Shell TORCULA® 32 into the
hose end (inlet) of the machine. Reconnect tool to the air supply
and run tool slowly for a few seconds to allow air to circulate the
oil. If the tool is used frequently, lubricate it on a daily basis or
lubricate it if the tool starts to slow or lose power.
It is recommended that the air pressure at the tool is 6.2 bar (90
psig) while the tool is running. The tool can run at lower pressures
but never higher than 6.2 bar (90 psig).

1) Read all instructions before using this tool. All operators must be fully trained in its use
and aware of these safety rules. All service and repair must be carried out by trained
personnel.

2) Make sure the tool is disconnected from the air supply. Select a suitable abrasive and
secure it to the back-up pad. Be careful and center the abrasive on the back-up pad.

3) Always wear required safety equipment when using this tool.

4) When sanding always place the tool on the work then

start the tool. Always remove the tool from the work
before stopping. This will prevent gouging of the work
due to excess speed of the abrasive.

5) Always remove the air supply to the sander before t­ting, adjusting or removing the abrasive or back-up pad.

6) Always adopt a rm footing and/or position and be

aware of torque reaction developed by the sander.

7) Use only correct spare parts.

8) Always ensure that the material to be sanded is rmly
xed to prevent its movement.

9) Check hose and ttings regularly for wear. Do not carry

the tool by its hose; always be careful to prevent the
tool from being started when carrying the tool with the
air supply connected.

10) Dust can be highly combustible. Vacuum dust collection

bag should be cleaned or replaced daily. Cleaning or
replacing of bag also assures optimum performance.

11) Do not exceed maximum recommended air pressure.

Use safety equipment as recommended.

12) The tool is not electrically insulated. Do not use where

there is a possibility of coming into contact with live
electricity, gas pipes, water pipes, etc. Check the area
of operation before operation.

13) Take care to avoid entanglement with the moving parts

of the tool with clothing, ties, hair, cleaning rags, etc. If entangled, it will cause the body
to be pulled towards the work and moving parts of the machine and can be very danger­ ous.

14) Keep hands clear of the spinning pad during use.

15) If the tool appears to malfunction, remove from use immediately and arrange for service

and repair.

16) Do not allow the tool to free speed without taking precautions to protect any persons or

objects from the loss of the abrasive or pad.

Work Stations

Proper Use of Tool

2

Parts Page

40

INLET

TO

DWG SCALE 1 : 31.

INLET

TO

2. ITEMS 46 AND 49 ARE TO BE RETAINED ON THE

61

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

38

37

39

BODY OF ITEM 47 AND 50 USING ITEM 48.

42

41

45

43

FOR CENTRAL VAC

TO VACUUM SYSTEM

46

47

50

48

49

51

52

53

54

55

56

57

58

59

60

44

NOTES:

62

1 in./28 mm HOSE SEALXPA077846

INSERT FOR MIRKA VACUUM BAGXPA046459

3/4 in. VAC HOSE TO DOUBLE BAG FITTING AND AIRLINE ASSYXPA041153

GNIRAEB 8 X 62 X 011200APX2

3 XPB0017 REAR ENDPLATE 1

6 XPB0005 MACHINED ROTOR 1
7 XPA0010 VANE 5

9 XPB0016 FRONT ENDPLATE 1

12 XPA0001 LOCK RING 1
13 XPB0279 5 x 3/32 in ORBIT AirS 1RECNALAB TFAHS ™sulP DLEIH
13 XPB0280 6 x 3/32 in. ORBIT Ai 1RECNALAB TFAHS ™sulP DLEIHSr
13 XPB0277 5 x 3/16 in ORBIT Ai 1RECNALAB TFAHS ™sulP DLEIHSr
13 XPB0278 6 x 3/16 in. ORBIT Ai 1RECNALAB TFAHS ™su
14 XPA0122 FILTER 1

16 XPA0120 VALVE RETAINER 1
17 N/A N/A -
18 XPA0938 12 x 28 x 16 DOUBLE ROW AN 1LAES 1 - GNIRAEB TCATNOC RALUG

21 XPA0018 RETAINING RING 1
22 XPB0018 SPINDLE 1
23 XPA1698 THROTTLE LEVER FOR MIRKA 12,000 RPM 2.5 mm (3/32 in.) ORBIT SANDERS 1
23 XPA1699 THROTTLE LEVER FOR MIRKA 12,000 RPM 5 mm (3/16 in.) ORBIT SANDERS 1
24 XPA0031 LEVER SPRING PIN 1

26 XPA0015 VALVE SLEEVE 1

72

30 XPB0014 SPEED CONTROL 1

34 XPC0073 Ø 6 in. SCREEN ABRA 1DUORHS ™CAVrepuS SOR EVIS

36 NA (ONE BACKUP PAD SUPPLIED WITH EACH TOOL - TYPE/SIZE MODEL DEPENDENT) 1

38 XPA0068 MUFFLER INSERT 1

40 XPA0009 VALVE SEAT 1
41 XPA0007 VALVE 1
42 XPA0014 VALVE SPRING 1
43 XPA0013

ITEM

TORQUE SETTING

in.-lbs. (Nm)

12 55 - 65 (6.2 - 7.3)
39 16 - 20 (1.8 - 2.3)
43 60 - 72 (6.8 - 8.1)
45 36 - 48 (4.1 - 5.2)
58 30 - 35 (3.4 - 3.9)

Original Instructions

3

Parts List

Item P/N Description Qty.

1 MPA0040 RETAINING RING 1
2 MPA0021 BEARING 1
3 MPB0017 REAR ENDPLATE 1
4 MPA0005 CYLINDER ASSEMBLY 1
5 MPA0042 O-RING 1
6 MPB0005 ROTOR 1
7 MPA0010 VANE 5
8 MPA0041 KEY 1
9 MPB0016 FRONT ENDPLATE 1

10 MPA0019 BEARING 1

11 MPA0045 O-RING 1
12 MPA0001 LOCK RING 1
13 MPB0348 8 mm (5/16 in.) ORBIT AirSHIELD™ SHAFT BALANCER FOR 125 mm (5 in.) PADS 1

MPB0334 8 mm (5/16 in.) ORBIT AirSHIELD™ SHAFT BALANCER FOR 150 mm (6 in.) PADS 1

14 MPA0122 FILTER 1

15 MPA0121 CHECK VALVE 1
16 MPA0120 RETAINER 1
18 MPA0938 DOUBLE ROW BEARING 1
19 MPA0016 SPACER 1
20 MPA0017 WASHER 1
21 MPA0018 RETAINING RING 1
22 MPB0018 SPINDLE 1
23 MPA2123 LEVER FOR 12,000 RPM, 125 mm (5 in.) / 150 mm (6 in.) PADS 8 mm (5/16 in.) ORBIT MACHINES 1
24 MPA0031 PIN 1
25 MPA0288 65 mm (2 1/2 in.) GRIP (Optional) OPTIONAL

MPA0289 70 mm (2 3/4 in.) GRIP (Optional) OPTIONAL

MPA0290 75 mm (3 in.) GRIP (Standard)) 1
26 MPA0015 SLEEVE 1
27 MPA0244 HOUSING 1
28 MPA0008 VALVE STEM ASSEMBLY 1
29 MPA0043 O-RING 1
30 MPB0014 SPEED CONTROL 1
31 MPA0039 RETAINING RING 1
32 MPB0012 125/150 mm (5/6 in.) NON-VACUUM SHROUD 1
33 MPC0012 SuperVAC™ SHROUD for 125 mm (5 in.) Delta, TE, LP and Screen Abrasive pads 1
34 MPC0073 SuperVAC™ SHROUD for 150 mm (6 in.) Screen Abrasive and LP Pads 1
35 MPA0022 24 mm PAD WRENCH (supplied with each tool) 1
36 NA SEE LITERATURE FOR PADS (type/size determined by model) 1
37 MPA0062 INTERNAL MUFFLER (for 12,000 RPM Machines) 1
38 MPA0068 MUFFLER INSERT(for 12,000 RPM Machines) 1
39 MPA0166 MUFFLER HOUSING 1

40 MPA0009 SEAT 1
41 MPA0007 VALVE 1
42 MPA0014 VALVE SPRING 1
43 MPA0013 INLET BUSHING 1
44 MPA0044 O-RING 2
45 MPA0006 SGV RETAINER 1
46 MPA0778 28mm (1 in.) HOSE SEAL 1
47 MPA0410 28 mm (1 in.) HOSE SuperVAC™ SGV SWIVEL EXHAUST ASSEMBLY (Standard for SGV)) 1
48 MPA0856 19mm (3/4 in.) HOSE SEAL TAG OPTIONAL

MPA0931 28mm (1 in.) HOSE SEAL TAG 1
49 MPA0854 19mm (3/4 in.) HOSE SEAL OPTIONAL
50 MPA0409 19 mm (¾ in.) HOSE SuperVAC™ SGV SWIVEL EXHAUST ASSEMBLY (Optional for SGV) OPTIONAL
51 MPC0108 SuperVAC™ SGV EXHAUST ADAPTER (for use with SuperVAC™ Shroud) 1
52

MPA0300

Ø 19 mm (¾ in.) VAC HOSE TO Ø 19 mm (¾ in.) x Ø 28 mm (1 in.) HOSE ADAPTER COUPLING AND
AIRLINE ASSEMBLY INCLUDES: MPA0200 Ø 19 mm (¾ in.) x 1.5 m (5 ft.) Vacuum Hose, MPB0088 19
mm (¾ in.) Hose x 28 mm (1 in.) Hose Adapter, MPA0302 Ø 6.3 mm (¼ in.) x 1.5 m (5 ft.) Airline with Fit­tings, MPA0301 Bungee for Ø 6.3 mm (¼ in.) Airline & Ø 19 mm (¾ in.) Vacuum Hose (5)

OPTIONAL

MPA0392

Ø 28 mm (1 in.) VAC HOSE TO Ø 28 mm (1 in.) x Ø 38 mm (1 ½ in.) FRICTION FIT ADAPTER AND AIR-

LINE ASSY. (Optional) INCLUDES: MPA0034 Ø 28 mm (1 in.) x 1.8 m (6 ft.) Vacuum Hose, MPB0092 Ø 28

mm (1 in.) Hose Thread x Ø 38 mm (1 ½ in.) Friction Fit Adapter, MPA0033 Ø 6.3 mm (¼ in.) x 1.8 m (6 ft.)
Airline with Fittings, MPA0027 Bungee for Ø 6.3 mm (¼ in.) Airline & Ø 28 mm (1 in.) Vacuum Hose (5)

OPTIONAL

53

MPA0412

Ø 28 mm (1 in.) VAC HOSE TO Ø 28 mm (1 in.) DOUBLE BAG FITTING AND AIRLINE ASSY. (Standard for

SGV) INCLUDES: MPA0034 Ø 28 mm (1 in.) x 1.8 m (6 ft.) Vacuum Hose, MPB0123 Ø 28 mm (1 in.) Hose

to Double Bag Vacuum Fitting, MPA0033 Ø 6.3 mm (¼ in.) x 1.8 m (6 ft.) Airline with Fittings, MPA0027
Bungee for Ø 6.3 mm (¼ in.) Airline & Ø 28 mm (1 in.) Vacuum Hose (5)

1

MPA0411

Ø 19 mm (¾ in.) VAC HOSE TO Ø 19 mm (¾ in.) DOUBLE BAG FITTING AND AIRLINE ASSEMBLY (Op­tional for SGV) INCLUDES: MPA0200 Ø 19 mm (¾ in.) x 1.5 m (5 ft.) Vacuum Hose, MPB0133 Ø 19 mm
(¾ in.) Hose To Double Bag Vacuum Fitting, MPA0302 Ø 6.3 mm (¼ in.) x 1.5 m (5 ft.) Airline with Fittings,
MPA0301 Bungee for Ø 6.3 mm (¼ in.) Airline & Ø 19 mm (¾ in.) Vacuum Hose (5)

OPTIONAL

54 MPA0099 SuperVAC™ CV 28 mm (1 in.) SWIVEL EXHAUST ASSEMBLY (Standard for CV) 1
55 MPA0048 NUT 1
56 MPA0205 SuperVAC™ CV 19 mm (¾ in.) SWIVEL EXHAUST ASSEMBLY (Optional for CV) OPTIONAL
57 MPA0047 WASHER 1
58 MPA0769 SCREW 1
59 MPA0465 10 PACK OF VACUUM BAG INSERTS 1
60 MPA0658 VACUUM BAG 1
61 MPA2541 FRONT BEARING DUST SHIELD 1
62 MPA2542 SPINDLE BEARING DUST SHIELD 1

4

Orbit

Vacuum

Type

Pad

Size mm

(inch)

Model

Number

Product

Net

Weight

kg

(pounds)

Height

mm

(inch)

Length

mm

(inch)

*Noise

Level

dBA

Power

watts

(HP)

Air Consump-

tion LPM

(scfm)

*Vibration

Level m/s2

*Uncer-

tainty

K

m/s

2

8.0 mm

(5/16 in.)

Non-

Vacuum

125 (5) MR-508

0.76

(1.68)

82.9 (3.26)

150.37
(5.92)

74

209

(.28)

481 (17) 2.0 1.0

150 (6) MR-608

0.79

(1.74)

82.9 (3.26)

163.42
(6.45)

77

209

(.28)

481 (17) 3.3 1.7

Central

Vacuum

125 (5) MR-508V

0.82

(1.81)

82.9 (3.26)

212.08
(8.35)

77

209

(.28)

481 (17) 2.4 1.2

150 (6) MR-608V

0.87

(1.92)

82.9 (3.26)

224.8

(8.85)

75

209

(.28)

481 (17) 3.5 1.8

Self-Gen.

Vacuum

125 (5) MR-508SGV

0.84

(1.85)

82.9 (3.26)

220.66
(8.68)

91

209

(.28)

481 (17) 2.5 1.3

150 (6) MR-608SGV

0.90

(1.98)

82.9 (3.26)

233.4

(9.18)

82

209

(.28)

481 (17) 3.4 1.7

The noise test is carried out in accordance with EN ISO 15744:2008 - Hand-held non-electric power tools -- Noise measurement code

-- Engineering method (grade 2).

The vibration test is carried out in accordance with EN 28662-1 Hand-held portable power tools – Measurement of vibration at the
handle. Part 1: General and EN 8662-8, 1997 Hand-held portable power tools – Measurement of vibration at the handle. Part 8:
Polishers and rotary, orbital and random orbital sanders.

Specications subject to change without prior notice.

*The values stated in the table are from laboratory testing in conformity with stated codes and standards and are not sufcient for risk

evaluation. Values measured in a particular work place may be higher than the declared values. The actual exposure values and amount
of risk or harm experienced to an individual is unique to each situation and depends upon the surrounding environment, the way in which
the individual works, the particular material being worked, work station design as well as upon the exposure time and the physical condi­tion of the user. KWH Mirka, Ltd. cannot be held responsible for the consequences of using declared values instead of actual exposure
values for any individual risk assessment.

Further occupational health and safety information can be obtained from the following websites:
http://europe.osha.eu.int (Europe)
http://www.osha.gov (USA)

Product Conguration/Specications: 12,000 RPM Random Orbital Sander

5

Symptom Possible Cause Solution

Low Power and/or Low Free
Speed

Insufcient Air Pressure Check air line pressure at the Inlet of the Sander

while the tool is running at free speed. It must be

6.2 Bar (90 psig/620 kPa).

Clogged Mufer(s) The Mufer can be back ushed with a clean, suit-

able cleaning solution until all contaminates and

obstructions have been removed. If the Mufer can

not be properly cleaned then replace it.

Plugged Inlet Screen Clean the Inlet Screen with a clean, suitable

cleaning solution. If Screen does not come clean
replace it.

One or more Worn or Broken Vanes Install a complete set of new Vanes (all vanes must

be replaced for proper operation). Coat all vanes
with quality pneumatic tool oil..

Internal air leakage in the Motor Housing
indicated by higher than normal air con­sumption and lower than normal speed.

Check for proper Motor alignment and Lock Ring
engagement. Check for damaged O-Ring in Lock
Ring groove. Remove Motor Assembly and Re­Install the Motor Assembly.

Motor Parts Worn Overhaul Motor. Contact authorized Mirka Service

Center.

Worn or broken Spindle Bearings Replace the worn or broken Bearings.

Air leakage through the Speed
Control and/or Valve Stem.

Dirty, broken or bent Valve Spring, Valve
or Valve Seat.

Disassemble, inspect and replace wore or dam­aged parts.

Vibration/Rough Operation

Incorrect Pad Only use Pad Sizes and Weights designed for the

machine.

Addition of interface pad or other material Only use abrasive and/or interface designed for the

machine. Do not attach anything to the Sanders

Pad face that was not specically designed to be

used with the Pad and Sander.

Improper lubrication or buildup of foreign
debris.

Disassemble the Sander and clean in a suitable
cleaning solution. Assemble the Sander.

Worn or broken Rear or Front Motor
Bearing(s)

Replace the worn or broken Bearings.

For vacuum machines it is possible to
have too much vacuum while sanding on a

at surface causing the pad to stick to the

sanding surface.

For SGV machines add extra washer(s) to the pad
spindle to increase the gap between the pad and
shroud. For CV machines reduce vacuum through
the vacuum system and/or add extra washer(s)
to the pad.

Troubleshooting Guiide

Note: All Sections referred to under “Solution” are located at the end of the manual in “Service Instructions”

DOC A2122 REV 05/04/12

KWH Mirka Ltd

Finland
Tel. [phone]
www.mirka.com
[e-mail]

Mirka (UK) Ltd

United Kingdom
Tel. [phone]
[e-mail]

Mirka Schleifmittel GmbH

Germany
Tel. [phone]
[e-mail]

Mirka Abrasives Inc.

USA
Tel. [phone]
www.mirka-usa.com

Mirka Scandinavia AB

Sweden, Norway, Denmark
Tel. [phone]
[e-mail]

Mirka Abrasifs s.a.r.l.

France
Tel. [phone]
[e-mail]

Mirka Italia s.r.l.

Italy
Tel. [phone]
[e-mail]
www.mirkaitalia.com

KWH Mirka Ibérica S.A.U.

Spain
Tel. [phone]
[e-mail]

KWH Mirka Mexicana S.A. de C.V.

México
Tel. [phone]
[e-mail]
www.mirka.com.mx

Mirka Brasil Ltda.

Brasil
Tel. [phone]
[e-mail]

Mirka Asia Pacific Pte Ltd

Singapore
Tel. [phone]
[e-mail]

Mirka Trading Shanghai Co., Ltd

China
Tel. [phone]
[e-mail]

Mirka Rus LLC

Russia
Tel. [phone]
[e-mail]

Mirka Abrasives Canada Inc.

Canada
Tel. [phone]
[e-mail]

Mirka India Pvt Ltd

India
Tel: [phone]
sale

[e-mail]

www.mirka.com

Quality from start to finish