ROS 550DB - Grinder Mirka - Free user manual and instructions

USER MANUAL ROS 550DB Mirka

Close-up of a MIRKO industrial power tool with black and white components (no visible text or symbols)

Stylized illustration of a bulldog in aggressive posture (no text or symbols)

Mirka® ROS

125 mm (5") · 150 mm (6")

Item P/N Description Qty.
1 MPA0040 RETAINING RING 1
2 MPA0021 BEARING 1
3 MFB0017 REAR ENDPLATE 1
4 MPA0005 CYLINDER ASSEMBLY 1
5 MPA0042 O-RING 1
6 MFB0005 ROTOR 1
7 MPA0010 VANE 5
8 MPA0041 KEY 1
9 MFB0016 FRONT ENDPLATE 1
10 MPA0019 BEARING 1
11	MPA0045 O-RING 1
12 MPA0001 LOCK RING			1
13	MPB0277 5 mm (3/16 in.) ORBIT AIRSHIELDTM SHAFT BALANCER FOR 125 mm (5 in.) PADS		1
	MPB0278 5 mm (3/16 in.) ORBIT AIRSHIELDTM SHAFT BALANCER FOR 150 mm (6 in.) PADS		1
	MPB0279 2.5 mm (3/32 in.) ORBIT AIRSHIELDTM SHAFT BALANCER FOR 125 mm (5 in.) PADS		1
	MPB0280 2.5 mm (3/32 in.) ORBIT AIRSHIELDTM SHAFT BALANCER FOR 150 mm (6 in.) PADS		1
14 MPA0122 FILTER			1
15 MPA0121 CHECK VALVE			1
16 MPA0120 RETAINER			1
17	N/A
18 MPA0938 DOUBLE ROW BEARING			1
19 MPA0016 SPACER			1
20 MPA0017 WASHER			1
21 MPA0018 RETAINING RING 1
22 MPB0018 SPINDLE			1
23	MPA1699 LEVER FOR 12,000 rpm, 125 mm (5 in.) / 150 mm (6 in.) PADS 5 mm (3/16 in.) ORBIT MACHINES		1
	MPA1698 LEVER FOR 12,000 rpm, 125 mm (5 in.) / 150 mm (6 in.) PADS 2.5 mm (3/32 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 SuperVACTM SHROUD for 125 mm (5 in.) Delta, TE, LP and Screen Abrasive pads		1
34	MPC0073 SuperVACTM 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 DB RETAINER			1
46 MPA0778 28mm (1 in.) HOSE SEAL			1
47 MPA0410 28 mm (1 in.) HOSE SuperVACTM DB SWIVEL EXHAUST ASSEMBLY (Standard for DB))			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 19mm (3/4 in.) HOSE SuperVACTM DB SWIVEL EXHAUST ASSEMBLY (Optional for DB)			OPTIONAL
51	MPC0108 SuperVACTM DB EXHAUST ADAPTER (for use with SuperVACTM Shroud)		1
52	MPA0300 ∅ 19 mm (3/4 in.) VAC HOSE TO ∅ 19 mm (3/4 in.) x ∅ 28 mm (1 in.) HOSE ADAPTER COUPLING AND AIRLINE ASSEMBLY INCLUDES: MPA0200 ∅ 19 mm (3/4 in.) x 1.5 m (5 ft.) Vacuum Hose, MPB0088 19 mm (3/4 in.) Hose x 28 mm (1 in.) Hose Adapter, MPA0302 ∅ 6.3 mm (1/4 in.) x 1.5 m (5 ft.) Airline with Fittings, MPA0301 Bungee for ∅ 6.3 mm (1/4 in.) Airline & ∅ 19 mm (3/4 in.) Vacuum Hose (5)		OPTIONAL
	MPA0392 ∅ 28 mm (1 in.) VAC HOSE TO ∅ 28 mm (1 in.) x ∅ 38 mm (1 1/2 in.) FRICTION FIT ADAPTER AND AIRLINE ASSY. (Optional) INCLUDES: MPA0034 ∅ 28 mm (1 in.) x 1.8 m (6 ft.) Vacuum Hose, MPB0092 ∅ 28 mm (1 in.) Hose Thread x ∅ 38 mm (1 1/2 in.) Friction Fit Adapter, MPA0033 ∅ 6.3 mm (1/4 in.) x 1.8 m (6 ft.) Airline with Fittings, MPA0027 Bungee for ∅ 6.3 mm (1/4 in.) Airline & ∅ 28 mm (1 in.) Vacuum Hose (5)		OPTIONAL
53	MPA0412 ∅ 28 mm (1 in.) VAC HOSE TO ∅ 28 mm (1 in.) DOUBLE BAG FITTING AND AIRLINE ASSY. (Standard for DB) INCLUDES: MPA0034 ∅ 28 mm (1 in.) x 1.8 m (6 ft.) Vacuum Hose, MPB0123 ∅ 28 mm (1 in.) Hose to Double Bag Vacuum Fitting, MPA0033 ∅ 6.3 mm (1/4 in.) x 1.8 m (6 ft.) Airline with Fittings, MPA0027 Bungee for ∅ 6.3 mm (1/4 in.) Airline & ∅ 28 mm (1 in.) Vacuum Hose (5)		1
	MPA0411 ∅ 19 mm (3/4 in.) VAC HOSE TO ∅ 19 mm (3/4 in.) DOUBLE BAG FITTING AND AIRLINE ASSEMBLY (Optional for DB) INCLUDES: MPA0200 ∅ 19 mm (3/4 in.) x 1.5 m (5 ft.) Vacuum Hose, MPB0133 ∅ 19 mm (3/4 in.) Hose To Double Bag Vacuum Fitting, MPA0302 ∅ 6.3 mm (1/4 in.) x 1.5 m (5 ft.) Airline with Fittings, MPA0301 Bungee for ∅ 6.3 mm (1/4 in.) Airline & ∅ 19 mm (3/4 in.) Vacuum Hose (5)		OPTIONAL
54	MPA0099 SuperVACTM CV 28 mm (1 in.) SWIVEL EXHAUST ASSEMBLY (Standard for CV)		1
55 MPA0048 NUT			1
56	MPA0205 SuperVACTM CV 19 mm (3/4 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

Sander Spare Parts Kits

Exploded view diagram of a mechanical component with no visible text or symbols

A MPA0797 12,000 rpm Muffler Kit Code: 8993017311

Exploded view diagram of a mechanical assembly showing layered components (no text or labels)

B MPA0802 ROS Spindle Bearing Kit Code: 8993019711

Technical line drawing of a mechanical component with no visible text or symbols

C MPA0798 Air Inlet Kit Code: 8993018811

Technical line drawing of a mechanical assembly with no visible text or symbols

D MPA0980 Shaft Balancer Kit 150mm/5,0 Kit Code: 8993010611 MPA1670 Shaft Balancer Kit 150mm/2,5 Kit Code: 8993013711

Technical line drawing of a mechanical component with mounting holes and a central shaft (no text or symbols)

E MPA0988 CV Swivel Fitting Kit Code: 8993006611

Technical line drawing of a mechanical component with no visible text or symbols

F MPA0994 Cylinder & O-ring Kit Code: 8993009211

Two concentric circular diagrams with internal lines, no text or symbols present

G MPA0993 Lock Ring & O-ring Kit Code: 8993007911

Technical line drawing of a mechanical assembly with cylindrical components and a shaft (no text or symbols)

H MPA0932 DB Swivel Fitting Kit Code: 8993011311

| MPA0799 Endplate Bearing Kit Code: 8993019811

J MPA0800 Speed Valve Kit Code: 8993019011

Technical line drawing of a mechanical component with no visible text or symbols

K MPA0801 Rotor, Vanes & Key Kit Code: 8993017711

Technical illustration of a handheld device and a threaded bolt assembly (no text or symbols)

L MPA0983 Lever Kit 5.0 mm orbit Code: 8993010811 MPA0984 Lever Kit 2.5 mm orbit Code: 8993010911
M MPA2551 DB Retainer Kit Code: 8993018911

(1) ا Courأ-JDistribution Relations, Development, and Information of the National Association for the United States. The information is provided in a format that is not possible to be extracted from this report.

Declaration of conformity

KWH Mirka Ltd.

66850 Jeppo, Finland

declare on our sole responsibility that the products

125 mm (5 in.) and 150 mm (6 in.) 12,000 rpm Random Orbital Sanders (see "Product Configuration/Specifications" Table for particular model) to which this declaration relates are in conformity with the following standard(s) or other normative document(s): EN ISO 15744:2008. Following the provisions of 89/392/EEC as amended by 91/368/EEC & 93/44/EEC 93/68/EEC Directives and consolidating Directive 2006/42/EC

Jeppo 09.03.2016

Place and date of issue

MIRKA

Company

Stefan Sjöberg, CEO

Operator Instructions

Includes – Please Read and Comply, Proper Use of Tool, Work Stations, Putting the Tool Into Service, Operating Instructions, Product Configuration/Specifications Tables, Parts Page, Parts List, Sander Spare Parts Kits, Trouble Shooting Guide

Important

Read these instructions carefully before installing, operating, servicing or repairing this tool. Keep these instructions in a safe accessible location.

C€

Manufacturer/Supplier

KWH Mirka Ltd. 66850 Jeppo, Finland

Tel: + 358 20 760 2111

Fax: [phone]

Required Personal Safety Equipment

Safety Glasses Breathing Masks

Safety Gloves Ear Protection

Recommended Airline Size - Minimum

10 mm 3/8 in

Recommended Maximum Hose Length

8 meters 25 feet

Air Pressure

Maximum Working Pressure 6.2 bar 90 psig Recommended Minimum NA NA

Please Read and Comply with

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

Proper Use of Tool

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 specified 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.

Work Stations

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 floor. It can be used in any position but before any such use, the operator must be in a secure position and have a firm grip and footing, and be aware that the sander can develop a torque reaction. See the section "Operating Instructions".

Putting the Tool into Service

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 filter, 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 the tool to the air supply and run the 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).

Operating Instructions

1) Read all instructions before using this tool. All operators must be fully trained in its use and be aware of these safety rules. All servicing and repairs 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. Take care to center the abrasive on the back-up pad.
3) Always wear the 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 disconnect the air supply from the sander before fitting, adjusting or removing the abrasive or back-up pad.
6) Always adopt a firm 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 firmly fixed to prevent its movement.
9) Check hose and fittings 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. The vacuum dust collection bag should be cleaned or replaced daily. Cleaning or replacement of the bag also assures optimum performance.
11) Do not exceed the 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 working area before operation.
13) Take care to avoid entanglement of 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 dangerous.
14) Keep hands clear of the spinning pad during use.
15) If the tool appears to malfunction, remove from use immediately and arrange for servicing 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.

graph TD
    A["Air Dryer"] --> B["Air Compressor and Tank"]
    B --> C["To Coupler at or near Tool"]
    C --> D["Drain Valve"]
    D --> E["Ball Valve"]
    E --> F["Filter"]
    F --> G["Lubricator"]
    G --> H["Regulator"]
    H --> I["Ball Valve"]
    I --> J["Sloped in the direction of air flow"]
    J --> K["Drain Leg"]
    K --> L["To Tool Station"]
    L --> M["Air Flow"]
    M --> N["Air Horse"]

Product Configuration/Specifications: 12,000 rpm Random Orbital Sander

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 Consumption LPM (scfm)	*Vibration Level m/s2	*Uncertainty K m/s^2
2.5 mm (3/32 in.)	Non-Vacuum	125 (5) R	OS525NV 0.72	(1.59) 82.9 (3.26)	148.4 (5.84)	79.0 209 (0.28)	481	(17) 2.10 1.10
		150 (6) R	OS625NV 0.76	(1.68) 82.9 (3.26)	161.1 (6.34)	83.0 209 (0.28)	481	(17) 3.30 1.70
	Central Vacuum	125 (5) R	OS525CV 0.78	(1.72) 87.7 (3.45)	148.4 (5.84)	78.0 209 (0.28)	481	(17) 2.29 0.72
		150 (6) R	OS625CV 0.85	(1.87) 82.9 (3.26)	161.1 (6.34)	79.0 209 (0.28)	481	(17) 2.14 0.71
	Shrouded Self-Gen. Vacuum	150 (6) R	OS625DB 0.85	(1.87) 82.9 (3.26)	164.1 (6.46)	84.0 209 (0.28)	481	(17) 2.11 0.70
5.0 mm (3/16 in.)	Non-Vacuum	125 (5) R	OS550NV 0.75	(1.65) 82.9 (3.26)	149.6 (5.89)	80.0 209 (0.28)	481	(17) 2.60 1.30
		150 (6) R	OS650NV 0.79	(1.74) 82.9 (3.26)	162.3 (6.39)	79.0 209 (0.28)	481	(17) 3.70 1.90
	Central Vacuum	125 (5) R	OS550CV 0.81	(1.79) 87.7 (3.45)	149.6 (5.89)	75.5 209 (0.28)	481	(17) 2.77 0.77
		150 (6) R	OS650CV 0.85	(1.87) 82.9 (3.26)	162.3 (6.39)	78.0 209 (0.28)	481	(17) 2.48 0.74
	Shrouded Self-Gen. Vacuum	125 (5) R	OS550DB 0.83	(1.83) 87.7 (3.45)	152.6 (6.01)	83.0 209 (0.28)	481	(17) 2.11 0.70
		150 (6) R	OS650DB 0.88	(1.94) 82.9 (3.26)	165.3 (6.51)	83.0 209 (0.28)	481	(17) 2.00 0.69

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) and EN ISO 11203:2009 Acoustics-Noise emitted by machinery and equipment-Determination of emission sound pressure levels at a work station and other specified positions from the sound power level.
The vibration test is carried out in accordance with EN ISO 28927-3, Hand-held portable power tools – Test method for evaluation of vibration emission – Part 3: Polishers and rotary, orbital and random orbital sanders.

Specifications 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 sufficient 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 are unique to each situation and depend 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: https://osha.europa.eu/en (Europe) http://www.osha.gov (USA)

Troubleshooting Guide

Symptom Possible Cause Solution
Low power and/or low free speed.	Insufficient 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 Muffler(s). See the “Housing Disassembly” section for Muffler removal. The Item 37 Muffler can be back flushed with a clean, suitable cleaning solution until all contaminates and obstructions have been removed. If the Muffler can not be properly cleaned then replace it. Replace Item 38, Muffler Insert (See the “Housing Assembly” Section).
	Plugged Inlet Screen. Clean the Inlet Screen	with a clean, suitable cleaning solution. If the Screen cannot be cleaned, 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. See “Motor Disassembly” and “Motor Assembly”.
	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. See “Motor Disassembly” and “Motor Assembly”.
	Motor parts worn. Overhaul Motor. Contact authorized Mirka Service Center.
	Worn or broken Spindle Bearings Replace the worn or broken Bearings. See “Shaft Balancer and Spindle Disassembly” and “Spindle Bearings, AirSHIELDTM and Shaft Balancer Assembly”.
Air leakage through the Speed Control and/or Valve Stem.	Dirty, broken or bent Valve Spring, Valve or Valve Seat.	Disassemble, inspect and replace worn or damaged parts. See steps 2 and 3 in “Housing Disassembly” and steps 2 and 3 in “Housing Assembly”.
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 specifically 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. (See “Service Manual”.)
	Worn or broken Rear or Front Motor Bearing(s).	Replace the worn or broken Bearings. See “Motor Disassembly” and “Motor Assembly”.
	For vacuum machines it is possible to have too much vacuum while sanding on a flat surface causing the pad to stick to the sanding surface.	For DB 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.

http://www.osha.gov (USA

1) 일반 산업 안전 보건 규정(General Industry Safety & Health Regulations, part 1910, OSHA 2206, 자료 제공: Superintendent of Documents; Government Printing Office; Washington DC 20402).

2) 휴대용 에어 공구 안진 규정(Safety Code for Portable Air Tools, ANSI B186.1, 자료 제공: American National Standards Institute, Inc.; 1430 Broadway; New York, New York 10018).

3) 주/지방 법규.

올바른 공구 사용법

https://osha.europa.eu/en(유럽)

http://www.osha.gov (미국)

문제 해결 가이드

Putting the Tool into Service

graph TD
    A["Slich's oil tank"] --> B["Flue gas"]
    B --> C["Flue gas valve"]
    C --> D["Flue gas valve"]
    D --> E["Flue gas valve"]
    E --> F["Flue gas valve"]
    F --> G["Flue gas valve"]
    G --> H["Flue gas valve"]
    H --> I["Flue gas valve"]
    I --> J["Flue gas valve"]
    J --> K["Flue gas valve"]
    K --> L["Flue gas valve"]
    L --> M["Flue gas valve"]
    M --> N["Flue gas valve"]
    N --> O["Flue gas valve"]
    O --> P["Flue gas valve"]
    P --> Q["Flue gas valve"]
    Q --> R["Flue gas valve"]
    R --> S["Flue gas valve"]
    S --> T["Flue gas valve"]
    T --> U["Flue gas valve"]
    U --> V["Flue gas valve"]
    V --> W["Flue gas valve"]
    W --> X["Flue gas valve"]
    X --> Y["Flue gas valve"]
    Y --> Z["Flue gas valve"]

KWH MIRKA LTD

Finland

Brazil Mirka Brasil Ltda.

Canada Mirka Abrasives Canada Inc.

China Mirka Trading Shanghai Co., Ltd

Finland & Baltics KWH Mirka Ltd

France Mirka Abrasifs s.a.r.l.

Germany Mirka Schleifmittel GmbH

India Mirka India Pvt Ltd

Italy Mirka Italia s.r.l.

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

Russia Mirka Rus LLC

Singapore Mirka Asia Pacific Pte Ltd

Spain KWH Mirka Ibérica S.A.U.

Sweden Mirka Scandinavia AB

Turkey Mirka Turkey Zimpara Ltd Şirketi

United Kingdom Mirka (UK) Ltd

USA Mirka Abrasives, Inc

For contact information,

please visit www.mirka.com

Quality from start to finish