Trelawny 735.7070 Troubleshooting guide

OPERATION & MAINTENANCE
4” ANGLE GRINDER

OPERATION
Foreword
Thank you for your purchase of the
TRELAWNY 4” Angle Grinder
This manual contains the necessary
maintenance information for you to
ensure proper operation and care for
this machine.
It is essential for you to read
through this manual thoroughly.
In the unlikely event that you
experience problems with your Angle
Grinder, please do not hesitate to
contact your local Trelawny dealer or
agent. We always welcome feedback
and comments from our valued
customers.
Safety Precautions
WEAR SAFETY BOOTS, FACE
MASK, SHATTERPROOF GLASSES,
HELMET, GLOVES and any other
personal protective equi pment
required for the working conditions.
Avoid loose clothing; this may become
trapped in moving parts and cause
serious injury.
A I R M O T O R S A R E N O T
ELECTRICALLY INSULATED.
ENSURE THAT HANDS and clothing
are kept away from rotating parts.
ONLY YOUR SUPERVISOR OR
A U T H O R I S E D M A I N T E N A N C E
ENGINEER should adjust the speed
control setting within the air motor;
although this has been set to the
optimum speed during manufacture,
the speed should be checked on a
daily basis.
ENSURE THAT THE WORK PLACE
IS W EL L VENTI LATED. A void
o p e r a t i n g e n g i n e - p o w e r e d
compressors in an enclosed area,
since engine exhaust gases are
poisonous.
BE AWARE, when the angle grinder is
switched off, the work head will
continue to rotate briefly.
Use of tool
This angle grinder is designed for use
with reinforced resin bonded depressed
centre grinding wheels that have a
permitted rotational speed in excess of
12,000rpm.
The tool is designed for light grinding
and dressing of welds, etc, but not for
cutting off.
The grinder must never be used
without a wheel guard fitted.
The air supply should be lubricated. It is
strongly recommended that an air filter,
regulator, lubricator is used, 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 lubricated by shutting off the air
supply to the tool, depressurising the line
by pressing the trigger on the tool.
Disconnect the air line and pour into the
air intake a teaspoonful (5ml) of a suitable
pneumatic motor lubricating oil preferably
incorporating a rust inhibitor.
Reconnect tool to air supply and run tool
slowly for a few seconds to allow air to
circulate the oil. If tool is used frequently
lubricate on daily basis and if tool starts to
slow or lose power.
Pre-Start Check (Daily)
Check all bolts and screws for tightness.
Ensure that all fittings are secure.
Check condition of hub or drum
assembly and replace flaps, cutters or
axles if required.
The air motor speed is preset at the
factory to 12,000 rpm (free running).
Always clear the air hose before
connection to the machine.
Ensure that no moisture (condensation)
is present in the air hose.
Check the security of all hoses clamps
and fittings, and that the air pressure is
correct at 90psi (6.2bar). The air motor
uses approximately 10cfm of air.
The Maximum air pressure is 100psi
(7bar) the air consumption will increase
as the air pressure rises.
It is recommended that the compressor
is capable of supplying at least 30cfm
supply of free air (not displaced, as given
by some compressor manufactures).
In particularly cold weather it is
recommended that a proprietary anti-
freeze lubricating oil is used.
Risk of Hand-arm
Vibration injury
These tools may cause Hand-arm
Vibration Syndrome injury if their use is
not adequately managed.
We advise you to carry out a risk
assessment and to implement measures
such as; limiting exposure time [i.e.
actual trigger time, not total time at
work], job rotation, ensuring the tools are
used correctly.
Ensure the tools are maintained
according to our recommendations, and
ensuring that the operators wear
personal protective equipment [PPE]
particularly gloves and clothing to
keep them warm and dry.
Employers should consider setting up a
programme of health surveillance to
establish a benchmark for each operator
and to detect any early symptoms of
vibration injury.
We are not aware of any PPE that
provides protection against vibration
injury by attenuating vibration emissions.
See „Specifications‟ section for vibration
emission data.
Grinding Discs, Flap
Wheels & Applications
Grinding Discs
851.4050 - for use on steel.
Flap Wheel
For the removal aggressive removal of
paint and coatings and heavy rust from
steel work, leaving a bright finish on steel
work.
851.4075 - 120 Grit flap wheel
851.4080 - 60 Grit flap wheel
851.4085 - 36 Grit flap wheel
Wire Cup Brush
For the removal of light paint and
coatings and rust from steel work.
851.4055 - 75mm dia - Crimped wire
brush.
851.4060 - 75mm dia - Twisted knot wire
brush.

OPERATION
Putting into service
Remove plastic bung from air
inlet using a pair of pliers.
Use a clean lubricated air supply
that will give a measured air
pressure to the tool of 6.3bar
(90psi).
It is recommended a air filter/
regulator/lubricator is used which
can be obtained from air tool
supplier.
Operating
With the grinder correctly connected to
the air supply, check the speed of the
grinder with an inlet pressure of 100
psi/7.0 bar measured at the tool inlet.
Check with a calibrated tachometer.
Check that the guard is in position and
securely fixed.
Check that the grinding wheel is of correct
dimensions, is not cracked or chipped and
has a permitted speed rating higher than
the maximum permissible running speed
of the grinder which is 12,000 RPM.
Check that item (5) disc receiver is the
correct type as parts list and is screwed
tightly to the shaft and locates the bore of
the grinding wheel on the spigot of the
disc receiver and screw on disc nut item
(4) using the spanners provided.
Do not over tighten as this could crack the
wheel. It should be tight enough to
prevent wheel spin off when the air supply
is shut off.
When first starting the grinder with a new
or changed wheel fitted, the grinder
should first be started in a protected area,
i.e. such as under a heavy bench well
away from other persons and run for one
minute.
This will provide protection if the wheel
should break because of a fault that was
not visibly detected
Always use eye protection and wear
protective gloves if there are sharp edges
in the working area.
The tool and the grinding process can
create a noise level such that ear
protectors should be worn.
If the grinding process creates dust then
use a suitable breathing mask.
Check that the material being worked will
not cause harmful dust or fumes. If this is
so then special breathing apparatus may
be required. Seek advice before starting
work.
If the grinder vibrates when first fitting the
wheel or during use, remove from service
immediately and arrange for the fault to
be corrected before continuing to use.
Do not apply excessive pressure as this
will reduce the cutting efficiency.
Apply light loads and allow the wheel to
cut.
Handle the grinder with care.
If the grinder is dropped, carefully
examine the wheel for damage and
replace if necessary.
Start the machine as if for the first time of
fitting a wheel, i.e. under a bench.
Make sure the object to be ground is in a
firm fixed position.
Dismantling & Assembly
Instructions
Disconnect tool from air supply.
Grip gear shaft (11) with spanner (41) and
insert spanner (40) into the holes in disc
nut (4), unscrew disc nut (4) and take off
grinding disc (34) and disc receiver (5),
remove 4 off screws (37) and take off disc
cover (3), retainer (7) and gasket (8).
Pull out the drive shaft assembly from
body (1). Unscrew grip (6) from body (1)
and remove 2 off screws (16) and take off
exhaust cover (48).
Remove spacer (14).
Support bearing (14) and tap the non
threaded end of the gear shaft (11) to
drive it through the bearing (14).
Take off retaining ring (13) from gear shaft
(11) and support bearing (9) on the
threaded shaft side and press the non
threaded end of gear shaft (11) through
the assembly to separate gear shaft (11),
key (12), bearing (9), bevel gear (10) and
wave washer (43).
By holding body (1) in a vice fitted with
soft jaws the control head assembly may
be removed from body (1) by unscrewing
lock ring (50). It is then possible to pull out
the motor and governor assembly from
the body (1).
Pull off pinion assembly from motor
assembly and press apart pinion (15) and
bearing (18).
Grip the front plate (20) by hand and with
a non metallic or soft metal (lead or
aluminium) hammer tap the splined end of
rotor (24) to drive the rotor and the
remainder of the motor and governor
assembly through the front plate and
bearing assembly.
Take off the cylinder (23) noting its
orientation for reassembly and take out 4
off rotor blades (25) from rotor (24).
Spring pin (22) may be pulled out of
cylinder (23) if a replacement is required.
Grip rotor (24) in a vice with soft jaws and
unscrew the governor assembly from the
rotor - left hand thread.
Support the rear end plate (26) in a piece
of tube with a bore as close as possible to
the maximum diameter of the rotor and
very carefully so as not to damage the
thread, tap the rotor through the rear end
plate (26) and bearing assembly.
With a suitable punch tap out bearing (17)
from rear end plate (26) and bearing (17)
from front plate (20).
To dismantle the governor assembly first
unscrew adjust screw (42) assembly.
Take off spring (28). Drive out 2 off spring
pins (47) and take out 8 off pendulums
(45) from governor (44).
When removing the pendulums take
special note of the orientation to the
governor (45) to ensure they are fitted the
same way on reassembly.
This is very important.
Grip valve housing (56) in a vice and
remove O-ring (39) from lock ring (50).
Drive out pin (58) and take off safety
throttle lever (60).
Do not dismantle the throttle lever (60).
Unscrew bushing (57).
Unscrew valve nut (52) and remove with
O-ring (53), spring (54), valve (59) and O-
ring (55).
Unscrew coupling nut (51) - left hand
thread - from valve housing (56) and
unscrew lock ring (50) from coupling nut
(51) and unscrew lock ring (50) from
coupling nut (51).

TECHNICAL SPECIFICATIONS
Description 4” Air
Weight 1.76kg/3.87lbs
Spindle dia M10
Power requirements 10cfm@90psi (1/4”BSP inlet)
Maximum air pressure 7 bar (100psi)
No load RPM 12,000 RPM
Recommended hose bore - to a max length 10 metres 10mm (3/8”)
Vibration (AEQ)
Primary hand position (trigger position) 5.1m/s2(k)
Test method in accordance with ISO standards 8662/1 & 8662/4
Noise
Noise LpA (Pressure Level) 82.9dB(A)
Test method in accordance with Pneurop test code PN8NTC1 & ISO Standard 3744
MAINTENANCE
For the motor make sure that the end
plates that abut the cylinder are free from
burrs and sharp edges and if necessary
lap on a flat fine grade of abrasive paper.
Press bearing (17) into rear case (26) and
support the inner race of bearing (17) and
press the non splined end of rotor (24)
into the assembly.
Tap the rotor relative to the rear case and
bearing assembly until a clearance of
approx. 0.0025” (0.065mm) is achieved
between the rotor and the rear case.
Ensure the rotor spins freely before
assembling the rest of the motor
assembly.
Reassembly
Clean all parts and examine for wear.
Use only distributor or manufacturer
supplied spare parts.
Particularly examine O-rings, bearings
and gears. Coat all parts in a pneumatic
tool lubricating oil, one preferably
containing a rust inhibitor.
Grease bearings and gears with a
molybdenum or lithium based general
purpose grease.
Reassemble in the reverse order.
This machine has a speed controller or
governor, parts (21), (28), (42), (44), (45)
and (46).
The correct setting of this speed controller
is critical to the safety of the tool and
should only be carried out by a trained
competent person.
The speed is set by assembling the speed
controller, measuring the output spindle
gear shaft (11) speed with a calibrated
tachometer.
Adjustment to the spindle speed can be
made by rotating adjust screw (42).
The speed of the grinder running free with
an air inlet pressure of 100 psi (7 bar)
measured at air inlet (57) must not
exceed 12,000 RPM.
EXPLODED VIEW

SAFETY RULES
Safety Rules for a Grinder
1) Read all the instructions before using this tool. All operators must be fully trained in its use and aware of these safety rules.
2) Do not exceed the maximum working air pressure.
3) Use personal protective safety equipment.
5) If the tool appears to malfunction remove from use immediately and arrange for service and repair.
6) If the tool is used with a balancer or other support device ensure that it is fixed securely.
7) Always keep hands away from the working attachment fitted to the tool.
8) The tool is not electrically insulated. Never use the tool if there is any chance of it coming into contact with a live electrical
source.
9) Always when using the tool adopt a firm footing and/or position and grip the tool firmly to be able to counteract any forces
or reaction forces that may be generated whilst using the tool.
10) Use only correct spare parts. Do not improvise or make temporary repairs.
11) Do not lock, tape, wire, etc. the on/off valve in the run position. The trigger/lever etc. must always be free to return to the
„off‟ position when it is released.
12) Always shut off the air supply to the tool, and depress the trigger/lever etc. to release air from the feed hose before fitting,
adjusting or removing the working attachment.
13) Check hose and fittings regularly for wear. Replace if necessary. Do not carry the tool by its hose and ensure the hand is
remote from the on/off control when carrying the tool with the air supply connected.
14) Take care against entanglement of moving parts of the tool with clothing, ties, hair, cleaning rags, etc. This will cause the
body to be drawn towards the tool and can be very dangerous.
15) Users will adopt safe working practices and observe all relevant legal requirements when installing, using or maintaining
the tool.
16) Do not install the tool unless an easily accessible and easily operable on/off valve is incorporated in the air supply.
17) Take care that the tool exhaust air does not cause a problem or blows on another person.
18) Never lay a tool down unless the working attachment has stopped moving.
19) A grinding wheel should only be fitted by a competent person trained to do so. The wheel must be of the correct size and
speed rating.
20) Check the speed of the grinder at least once per week, if it is in regular use, with an accurate tachometer.
21) The tool must only be used with the grinding wheels as set out in section “Use of the Tool” and shown on parts list. Never
fit any other device.
22) Carry out the instructions as set out in “Putting into Service”.
23) Many countries have local or national rules re the use and fitting of grinding wheels. Make sure such rules are observed.
24) Use a barrier to prevent sparks causing a hazard to the operator, any other person or anything within the vicinity of the
sparks.
25) If a wheel guard becomes damaged or has withstood a wheel breakage, the guard must be changed.
26) Do not use chipped or cracked grinding wheels.
27) Always wear impact resistant eye protection.
28) Use only the disc plates, Items (4) and (5) provided with the grinder for locating and clamping the wheel. Never use
substitutes. Use the paper blotter fixed to the wheel as this ensures even tightness when the wheel is secured.
29) Tighten the wheel plates sufficiently to prevent wheel spin off when the grinder is turned off. Do not tighten excessively as
this may crack the wheel.
30) The noise from the tool or the process noise of the grinding operation may be such that hearing protection should be
worn.
31) Avoid inhaling dust from the grinding process. Wearing of a breathing mask is recommended. Grinder certain materials
may mean that special breathing precautions are necessary. Seek advice before using the tool.
32) Always ensure that the work piece is firmly supported so that it cannot move during the grinding process.
33) If the grinder is dropped do not use unless the wheel is first checked for damage by a competent person.
34) When not in use the grinder should be stored in a safe place where it will not be damaged. If a tool has not been used for
a period of time check the tool as for the first time of using.
35) Be aware that if the grinding process causes high vibration, special precautions should be taken.
36) The operator should be aware that the grinding wheel will continue to rotate after the power supply has been shut off. This
could cause a hazard.
37) Always store grinding wheels in accordance with the manufacturer‟s instructions.
38) Check frequently that the spindle thread has not become damaged or worn.
39) Always ensure that the grinding wheel has a higher permissible running speed to the speed of the grinder.

PARTS LIST
Trelawny tools are thoroughly tested under specified conditions in accordance with applicable internationally recognised standards. When a tool is used on site the
conditions may not be the same as those used in our tests
Trelawny Surface Preparation Technology operates a policy of continuous product development and refinement and therefore reserves the right to change technical
specifications and product designs without giving prior notice.
© Copyright 2013, Trelawny SPT Limited, CV31 1XT. UK All rights reserved. Any unauthorised use or copying of the contents or part thereof is prohibited. This applies to
trademarks, model denominations, part numbers and drawings.
Use only genuine Trelawny spares.
The use of non-Trelawny spare parts invalidates the warranty.
SURFACE PREPARATION TECHNOLOGY
Trelawny SPT Limited
Trelawny House, 13 Highdown Road, Sydenham Industrial Estate,
Leamington Spa, Warwickshire, CV31 1XT, United Kingdom
Telephone: [phone] Fax: [phone] Email: [e-mail]
General Industry Website: www.trelawnyspt.com
Dedicated Marine Website: www.trelawny-marine.com
© TSPT UK 2013 Part No: 735.7070 issue1
Ref Part No Description
1 370.25001A Body
2 370.250002 Screw
3 370.250003 Disc cover
4 370.250004 Disc nut
5 370.250005 Disc receiver
6 370.250006 Handle
370.5G619753 Vibration reduced handle
7 370.250007 Retainer
8 370.250008 Gasket
9 370.250009 Ball bearing
10 370.250010 Bevel gear
11 370.250011 Gear shaft
12 370.250012 Key
13 370.250013 Retaining ring
14 370.250014 Ball bearing
15 370.250015 Pinion gear
16 370.250016 Screw (2)
17 370.250017 Ball bearing (2)
18 370.250018 Ball bearing
19 370.250020 Spacer
20 370.250021 Front plate
21 370.832H01 Governor assembly
22 370.250024 Sprint pin
23 370.250025 Cylinder
24 370.250026 Rotor
25 370.250027 Rotor blades (4)
26 370.250028 Rear plate
28 370.250030 Spring
Ref Part No Description
34 851.4060 75mm twisted knot cup brush
851.4050 Disc wheel (For use on steel)
491.4050 Pack of 5 x Disc wheel
851.4075 120grit Flap wheel
851.4080 60grit Flap wheel
851.4085 36grit Flap wheel
36 370.250061A Valve bushing
37 370.250039 Cap screw (4)
39 370.250041 O‟Ring
40 370.250042 Disc spanner
41 370.250043 Stop spanner
42 370.250044 Adjuster screw
43 370.250045 Wave washer
44 370.250046 Governor
45 370.250047 Pendulum (8)
46 370.250048 Plunger
47 370.250049 Spring pin (2)
48 370.250050 Exhaust cover
50 370.250052 Lock ring
51 370.250053 Coupling ring
52 370.250054 Valve screw
53 370.250055 O‟Ring
54 370.250056 Valve spring
55 370.250057 O‟Ring
56 370.250058 Valve housing
57 370.250059 Hose adaptor
58 370.250080 Spring pin
59 370.250061 Valve pin
60 370.250062 Complete lever assembly