Clarke CBG250 User guide

250MM BENCH GRINDER

MODEL NO: CBG250

PART NO: 6500104

OPERATING & MAINTENANCE

INSTRUCTIONS

ORIGINAL INSTRUCTIONS GC 05/25

INTRODUCTION

Thank you for purchasing this CLARKE Bench Grinder.

Before attempting to use this product, please read this manual thoroughly and follow
the instructions carefully. In doing so you will ensure the safety of yourself and that of
others around you, and you can look forward to your purchase giving you long and
satisfactory service.

GUARANTEE

This product is guaranteed against faulty manufacture for a period of 12 months from
the date of purchase. Please keep your receipt which will be required as proof of
purchase.

This guarantee is invalid if the product is found to have been abused or tampered
with in any way, or not used for the purpose for which it was intended.

Faulty goods should be returned to their place of purchase, no product can be
returned to us without prior permission.

This guarantee does not effect your statutory rights.

SPECIFICATIONS

Weight 30.4kg

Product dimensions (L x W x H) 350 x 500 x 350mm (guards & tool rest fitted)

Grinding Stone Dimensions 250 dia x 25 mm thick (20mm bore)

Grinding Stone grade 36 Coarse/60 Medium (max 4450 rpm)

Rated Voltage / Frequency 230 V / 50 Hz

Rated Input Wattage 750 W

No Load Speed 2980 rpm

Ingress protection rating IP20

Duty cycle classification S1

Cable length 1.75m

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GENERAL SAFETY RULES

CAUTION: FAILURE TO FOLLOW THESE PRECAUTIONS COULD RESULT IN
PERSONAL INJURY, AND/OR DAMAGE TO PROPERTY.

WORK ENVIRONMENT

1. Keep the work area clean, tidy and well lit. Cluttered and dark areas invite
accidents

2. DO NOT operate power tools in explosive atmospheres, such as in the presence
of flammable liquids, gases or dust. Power tools create sparks which may ignite
the dust or fumes.

3. Keep children and bystanders away while operating a power tool. Distractions can
cause you to lose control.

PERSONAL SAFETY

1. Stay alert, watch what you are doing and use common sense when operating a
power tool. DO NOT use a power tool while you are tired or under the influence
of drugs, alcohol or medication. A moment of inattention while operating power
tools may result in personal injury.

2. Avoid accidental starting. Ensure the switch is in the off position before plugging
in. Plugging in power tools that have the switch on invites accidents.

3. DO NOT overreach. Keep proper footing and balance at all times. This enables
better control of the power tool in unexpected situations.

4. Dress properly. DO NOT wear loose clothing or jewellery. Keep your hair, clothing
and gloves away from moving parts. Loose clothes, jewellery or long hair can be
caught in moving parts.

5. Eye protection manufactured to the current European safety standards should be
worn when operating grinding equipment. Eye protectors must provide protection
from flying particles from the front and the side.

GENERAL USE AND CARE OF POWER TOOLS

1. ALWAYS check for any damage or condition that could affect the grinder’s
operation. Any damaged part should be properly repaired.

2. NEVER use the grinder if it is defective or operating abnormally.

3. NEVER abuse the mains cable. NEVER yank the cable to disconnect it from the
socket. Keep the cable away from sharp edges/hot surfaces.

4. NEVER carry out any alterations or modifications to this product.

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5. NEVER wipe the machine clean with solvents. Wipe plastic parts with a soft cloth,
slightly dampened with soapy water.

6. NEVER attempt any repairs yourself. If you have a problem with this product
contact your local CLARKE dealer.

7. DO NOT use the tool for any purpose than that described in this manual.

8. ALWAYS maintain the tool with care. Keep it clean for the best and safest
performance.

9. DO NOT force the power tool. Use the correct power tool for your application.
The correct power tool will do the job better and safer at the rate which it was
designed.

10. DO NOT use the power tool if the switch does not turn it on and off. Any power
tool that cannot be controlled with the switch is dangerous and must be repaired.

11. Store idle tools out of the reach of children and do not allow persons unfamiliar
with the power tool or these instructions to operate the power tool. Power tools
are dangerous in the hands of untrained users.

12. Maintain power tools. Check for misalignment or binding of moving parts,
breakage of parts and any other condition that may affect the power tools
operation. If damaged, have the power tool repaired before use. Many accidents
are caused by poorly maintained power tools.

13. Use the power tool and accessories in accordance with these instructions and in
the manner intended for the particular type of power tool, taking into account the
working conditions and the work to be performed. Use of the power tool for
operations different from intended could result in a hazardous situation.

ELECTRICAL SAFETY

1. Power tool plugs must match the outlet. NEVER modify the plug in any way. DO
NOT use adapter plugs with earthed (grounded) power tools. Correct plugs and

matching outlets will reduce the risk of electric shock.

2. DO NOT abuse the cable. NEVER use it for carrying, pulling or unplugging the
power tool. Keep the cable away from heat, oil, sharp edges or moving parts.
Damaged or entangled cables increase the risk of electric shock.

3. DO NOT expose power tools to rain or wet conditions. Water entering a power
tool will increase the risk of electric shock. If operating the power tool in a damp
location is unavoidable, use a residual current device (RCD) protected supply.

4. When operating a power tool outdoors, use an extension cable suitable for
outdoor use. Use of a cable suitable for outdoor use reduces the risk of electric
shock.

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GRINDING STONE SAFETY

1. Check the speed of the grindstone before fitting to your grinder. NEVER use a
stone with a rpm speed less than the rpm speed of your grinder. See specification
on page 2.

2. The outside diameter and thickness of your accessories must be within the
capacity rating of the power tool. The correct size accessories can be correctly
guarded and controlled.

3. NEVER use a stone that is chipped, cracked or damaged. Fragments from a
broken or damaged grinding stone can cause serious injury. Make sure that
defective stones are destroyed and not used.

4. Bonded abrasive products are breakable and shall therefore be handled with
utmost care. The use of damaged or improperly mounted or used abrasive
products is dangerous and can cause serious injuries.

5. ALWAYS refer to the label for specified usage and observe the safety
information. DO NOT use for purposes other than specified.

6. ALWAYS use the correct stone for it’s intended task. Using the incorrect stone
can cause serious injury.

7. Allow the stone and tool to do the work. NEVER force the workpiece against the
stone as this could cause kickback and/or shatter the stone causing serious injury.

8. DO NOT use separate reducing bushes or adapters to adapt large hole abrasive
wheels. DO NOT force a stone onto a machine or alter the size of the arbor hole.

9. NEVER use a damaged grinding stone. Inspect the stone before each use for
chips, cracks or excess wear. If the tool or accessory is dropped, inspect for
damage or install a new accessory. After fitting the accessory, position yourself
away from the plane of the rotating accessory and run the tool at full speed.
Damaged stones may break apart during this test.

10. Abrasive products shall be handled and transported with care. Abrasive products
shall be stored in such a manner that they are not subjected to mechanical
damage and harmful environmental influences.

BENCH GRINDER SAFETY WARNINGS

1. Hold a hand tool or blade being sharpened firmly to prevent loss of control.

2. NEVER install a abrasive flap wheel or sanding disc on this grinder.

3. ALWAYS replace a cracked grinding wheel immediately.

4. NEVER use damaged or incorrect grindstones. The stone and retaining fixtures
were specially designed for your grinder, for optimum performance and safety of
operation. Inspect the condition of the grinding stone before use and do not use if
any damage is found.

5. ALWAYS use the tool rests to steady the workpiece, the torque of the spinning
grinding wheel may pull the workpiece from your hands.

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6. ALWAYS check for damaged parts. Before further use any part that is damaged
should be carefully checked to determine if it would operate properly and perform
its intended function. Check for misalignment or binding of moving parts,
breakage of parts and any other condition that may affect the tool's operation. A
part that is damaged should be properly repaired or replaced at an authorised
service center. Following this rule will reduce the risk of electric shock, fire or
serious injury.

NOTE: Bench grinders used in industrial environments may be subject to the

requirements of The Provision and Use of Work Equipment regulations
1992 (particularly regarding the training requirement of The Abrasive
Wheels Regulations 1970), or other legislation. If in doubt seek advice.

Please keep these instructions in a safe place for future reference.

SAFETY SYMBOLS

The meanings of the markings and symbols on the product are shown below

Read this manual before
use and keep in a safe
place for future
reference

Wear ear protection
when grinding.

Wear eye protection when
using this tool.

Wear dust mask.

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ELECTRICAL CONNECTIONS

WARNING! READ THESE ELECTRICAL SAFETY INSTRUCTIONS
FULLY BEFORE CONNECTING THE MACHINE TO THE MAINS
SUPPLY.

This machine is provided with a standard 13 amp, 230 volt (50Hz), BS 1363 plug, for
connection to a standard, domestic electrical supply. Should the plug need changing,
make sure that a plug of identical specification is used.

WARNING! THE WIRES IN THE POWER CABLE OF THIS PRODUCT
ARE COLOURED IN ACCORDANCE WITH THE FOLLOWING CODE:
BLUE = NEUTRAL BROWN = LIVE YELLOW AND GREEN = EARTH

If the colours of the wires in the power cable do not agree with the markings on the
plug:

• Connect the blue wire

to the terminal marked
N.

• Connect the brown wire

to the terminal marked
L.

• Connect the yellow

and green wire to the
terminal marked E or

We strongly recommend that this machine is connected to the mains
supply through a Residual Current Device (RCD)

If you are not sure, consult a qualified electrician. DO NOT try to do any repairs.

(Green and
Yellow)

Plug must be BS1363/A approved.

Earth

Neutral

(Blue)

Ensure that the outer sheath of
the cable is firmly held by the clamp

Always fit
a 13 Amp
fuse.

Live

(Brown)

EXTENSION CABLES

Always use an approved cable extension suitable for the power rating of this machine.
The conductor size should also be at least the same size as that on the machine, or
larger and should have an earth conductor.

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OVERVIEW

The following items should be supplied with the bench grinder. If any items are
missing or damaged, please contact the CLARKE dealer where you purchased the
product.

• Two eye shield assemblies (each with keep plate, bolt & flat washer)

• Two spark guards (each with 2 x screws & flat washers

• Two tool rests (each with supporting arm, finger knob, wing nut, coach-

bolt & flat washer)

• Coarse wheel (fitted)

• Medium wheel (fitted)

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ASSEMBLY

1. Assemble the tool rests with the
locking knobs, short coach bolts and
small washers provided.

2. Install the tool-rests to the machine
by screwing the wingnuts (with large
washers) through the adjusting
brackets as shown.

• The tool rests are adjustable and

should be positioned 2.5mm
(1/8") from the grinding wheels.
Ensure that the tool rest is firmly fixed and horizontal.

• As the wheel wears down with use, it will be necessary to re-position the

toolrest brackets in order to maintain a gap between the rest and the
grinding wheel.

3. Install the spark guards to the
machine frame using the x-head
screws and small washers supplied as
shown. Adjust their position as close
to the grinding wheel as possible.

4. Install the eye shields onto the
machine using the keep plates, bolts
and washers supplied as shown.

• The angle for the eye shields can

be adjusted to suit the operator.

IMPORTANT: We recommend that
your bench grinder is secured to
your workbench before operation,
using the pre-drilled holes in the
base. DO NOT over-tighten the
mounting bolts as this could damage the base. Position the machine in
good light.

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USING YOUR BENCH GRINDER

WARNING: FRAGMENTS FROM A BROKEN/DETACHED GRINDING
WHEEL CAN CAUSE INJURY.

WARNING: ENSURE THAT THE WORKING POSITION ADOPTED DOES
NOT CAUSE OPERATOR FATIGUE WHICH MAY LEAD TO LOSS OF
CONTROL OF THE TOOL BEING GROUND.

WARNING: THE WHEEL WILL CONTINUE TO ROTATE BRIEFLY
AFTER THE OFF SWITCH HAS BEEN PRESSED.

GENERAL USE

1. To start/stop the grinder press the ON/OFF switch and start work.

2. Press the tool blade evenly onto the grinding stone and move the tool sideways
across the stone. Make sure that at least half the width of the tool cutting edge
comes into contact with the grinding stone at any time to avoid damage to the
stone.

3. Allow the stone to do the work. DO NOT apply excessive downward pressure on
the tool when grinding.

EYESHIELD ADJUSTMENT

The transparent eye shields allow the user to see the work clearly and to work
precisely. The eye shields can be adjusted up and down as required.

The brackets should be adjusted so that they are as close as possible to the grinding
wheel without impairing the wheels rotation.

IMPORTANT: Even though the eye shields are fitted, you should
nevertheless wear safety goggles when operating a bench grinder.

TOOLREST ADJUSTMENT

The appropriate adjustment of the tool rests provides the operator with a correct
working angle and a firm and efficient base for working. Adjustments can be made by
loosening the mounting screws and moving the tool rest to within 1.6mm (1/16”)
from the wheel.

Due to the wear on the grinding wheel, it will be necessary to adjust the tool rests
from time to time. Always re-tighten the mounting thumbscrews once adjustment is
complete.

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MAINTENANCE

GENERAL MAINTENANCE

Make sure that all components are tight and secure. Always have any damaged or
worn parts repaired or replaced by qualified service personnel. DO NOT attempt to
repair the grinder unless you are qualified to do so.

The drive motor and bearings are sealed units and require no regular maintenance.
Should you require assistance, contact your local CLARKE service agent.

The stone will wear down with use and may well go out of true. Use a dressing wheel
or stone grader to correct the trueness and to remove worn, glazed grains from the
stone.

The stone will have a finite life expectancy, dependent upon the nature of the work
being done. Periodically, make a note of the wheel diameter and replace your
(150mm) dia wheel if it reduces to an little as (130mm) in diameter.

INSTALLING A NEW GRINDING STONE

CAUTION: NEVER RE-START THE GRINDER WITHOUT THE GUARDS
INSTALLED.

To renew or change the grinding wheels, proceed as follows

1. Switch off and un-plug from power supply. Remove the outer covers, left or right,
by removing the three cover retaining screws.

2. Hold the grinding wheel firmly and remove the nut and flange from the shaft,
noting that the left hand wheel nut has a left hand thread.

3. Take off the used wheel and replace with the new one, ensuring:

• the paper label/blotters are in place either side of the wheel.

• that there is a good balanced rotation of the grinding wheel

• you do not over-tighten the wheel nut.

4. Re-fit covers, left or right, by using the three cover retaining screws.

5. Re-adjust the tool rest and spark arrester brackets if required.

6. Switch the machine on and allow it to rotate freely for at least one minute.

Replacement grinding stones are available from your CLARKE dealer.

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DRESSING A NEW STONE

New grinding stones are frequently not true or in time can become grooved, glazed
(built-up), out of round or otherwise mis-shapen. To correct these defects, a grinding
stone dresser is available from your CLARKE dealer.

• ET125 Traditional Grinding Wheel Dresser - Part No:1700225

• ET154 ½ Carat Diamond Tip Wheel Dresser - part No:1700329

1. If the grinding stone is new, allow it to spin for a minute with no load. Check that
it is spinning straight and true. If not, it will require dressing before use.

2. Stand to the side of the stone and hold the dresser handle firmly. Place the
dresser on the tool support so that its wheels can move freely (i.e, the exposed
part of the wheel should be facing up). Run the stone and apply the dresser to the
surface of the stone.

CLEANING & STORAGE

Clean the exterior the machine if required using a mild detergent or mild solvent.
Never immerse the machine in water. To reduce any fire hazard, keep any cooling
vents in the grinder free of debris.

If not bolted to a workbench, store the grinder in a clean, dry location, out of reach of
children.

Replacement 250mm grinding wheels are available:

• Coarse - part no 6500097

• Medium - part no 6500096

• Fine - part no 6500094

ENVIRONMENTAL PROTECTION

Do not dispose of this product with general household waste. All tools,
accessories and packaging should be sorted, taken to a recycling centre
and disposed of according to the laws governing Waste Electrical and
Electronic Equipment.

Through the purchase of this product, the customer is taking on the obligation to deal
with the WEEE in accordance with the WEEE regulations in relation to the treatment,
recycling & recovery and environmentally sound disposal of the WEEE.

In effect, this means that this product must not be disposed of with general
household waste. It must be disposed of according to the laws governing Waste
Electrical and Electronic Equipment (WEEE) at a recognised disposal facility.

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DECLARATIONS OF CONFORMITY

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COMPONENT PARTS

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COMPONENT PARTS

No Description No Description

1 Hex nut 29 Power cable

2 Left wheel cover 30 Philips screw

3 Nut 31 Cable gland

4 Retaining disc 32 Cable clamp

5 Grinding wheel 33 Cable clamp

6 Philips screw/spring washer 34 Cable gland

7 Eyeshield assembly 35 Philips screw

8 Left eye-shield support 36 Cable clamp

9 Eyeshield bracket 37 Hex bolt /spring washer

10 Flat washer 38 Nut

11 Hex bolt 39 Capacitor support

12 Spark deflector 40 Cover plate

13 Philips screw/spring & flat washer 41 Rubber foot

14 Philips screw/spring washer 42 Philips screw/washer

15 End cap 43 Flat washer

16 Wave spring 44 Right fixed worktable

17 Bearing 45 Capacitor

18 Retaining ring 46 Philips screw

19 Motor rotor 47 Switch

20 Motor stator 48 Base

21 Right eye-shield support 49 Screw/spring washer/flat washer

22 Nut 50 Tooth washer

23 Right wheel guard cover 51 Pin

24 Bolt 52 Earthing plate

25 Left fixed work rest 53 Grinding wheel

26 Flat washer 54 Right movable work table

27 Lock knob 55 Switch panel

28 Lock nut knob

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