Cembre RDS-20P, SA-RDS, SAY1-RDS, RDSC-20P, RDS-20P-SA Operation And Maintenance Manual

RAIL SAW

RDS-20P
RDSC-20P

18 M 187 E

ENGLISH

PATENT
PENDING

1

Before using the machine, carefully read the instructions
contained in this manual.
SAVE THESE INSTRUCTIONS: this manual contains important
safety and operating instructions for the machine.

It is mandatory to wear approved personal protective equip­ment, such as:

- Flame retardant clothing.

- A helmet, goggles or face shield.

- Gloves.

- Airway protective mask.

- Ear protectors.

- Boots with anti-slip soles and steel toe-caps.

The user is responsible for the machine and must be properly informed
about its use and the risks arising from improper use, which could
cause injury or even death.
Comply with appropriate rest periods and avoid prolonged exposure
to vibrations and noise.

During cutting, dust and waste particles are released, including exhaust
gas and petrol fumes, which can be inhaled.

Keep the rail saw fi rm during cutting in order to avoid hazardous
kickback.

When cutting, hot sparks fl y off which can cause fi re when in the
presence of fl ammable material such as dry grass, petrol, wood, etc.

Keep hands away from the danger zone

.

2

• Carefully follow the safety instructions set out by Cembre. Failure to observe these warnings
and the incorrect or improper use of the RAIL SAW may cause serious injury to the operator
and others close by.

• Always use personal protective equipment provided by your employer as result of a risk
evaluation prescribed by current national safety legislation, including: flame retardant
clothing, goggles or face shield, ear protectors, helmet, gloves, boots with anti slip soles
and steel toe-caps, airway protective mask.

• Anyone who uses or operates the RAIL SAW must first read this user manual carefully and be
familiar with the controls. The machine should only be used by trained, competent
personnel.

• Do not use the RAIL SAW for purposes other than those intended by Cembre or for
grinding operations using the side surface of the cutting disc as this may break and
cause serious injury. Never use a machine that is faulty, has been tampered with or
which has been modified from its original form.

• Control the surrounding area before operation; the safety distance around the RAIL
SAW for personnel not operating the machine should be at least 15 metres. Hot
sparks which fly off during cutting can cause fire if in the presence of flammable
materials such as dry grass, petrol, wood, etc.

• The RAIL SAW must only be used in conjunction with support arms supplied by Cembre.

• Never operate the RAIL SAW during personal ill health, when tired or under
the effects of alcohol, drugs or medicines which can alter the state of mind
and reduce reaction times; use good judgement in all situations.

• When operating, stand in a stable, secure position and grip the RAIL SAW tightly.
Be sure to work in good lighting conditions or with sufficient artificial lighting.

• Always keep a first aid kit and fire extinguisher on hand in order to intervene promptly
should remove the need arise.

• Avoid inhalation of Petrol fumes and exhaust emissions which contain Carbon Monoxide,
an odourless lethal gas. Ensure good ventilation.

• The fuel and its vapours are extremely flammable.
FIRE AND BURN HAZARD.

• Turn off the engine before refuelling. Dry any spilt fuel.
If the fuel comes into contact with clothing, change the clothing immediately.
Do not start the engine within 3 metres of the refuelling area.

• During transportation, always remove the cutting disc from the RAIL SAW.

3

Descriptions and possible confi gurations:

REFERENCE

RDS-20P
RDSC-20P *

SA-RDS

SAY1-RDS

RDS-20P-SA
RDSC-20P-SA *

RAIL SAW

STANDARD

SUPPORT ARM

•

•

••

SUPPORT ARM

FOR GIRDER RAILS

•

* RDSC...type rail saws are provided with a support arm ignition control, it works only
if mounted on the support arm. If the rail saw is not mounted onto the support arm,
an automatic cut-off device stops the engine!

Main components (Ref. Fig. 1 page 5):

1

– Air fi lter spark plug cover

2

– Upper handle

3

– Safety guard (spark guard)

4

– Abrasive cutting disc (to be mounted)

5

– Transmission system side cover

6

– Foot

7

– Nameplate

8

– Support arm pin slot

9

– Silencer / muffl er

10

– (EasyStart) Decompression valve

11

– Combustion engine

12

– Abrasive cutting disc fi xing

13 – Measure for petrol-oil mix

14 – 4mm Allen key for removing side cover

15 – Starter cord grip

16 – Multifunction spanner (torx + cut)

17 – Fuel tank cap

18 – Main ON/OFF switch

19 – Rear control handle

20 – Accelerator

21 – Safety lever

22 – Accelerator block

23 – Air valve control (starter)

4

FIG. 1

2

1

3

11

4

10

9

8

7

6

5

12

5

13

8

14

15

16

17

18

23

22

21

20

19

3.1) General Characteristics:

RDS-20P RDSC-20P

Application range Rail saw is designed to cut rail with suitable abrasive disc

support arm ignition control NO YES

dimensions refer to Fig. 2 , page 31

weight kg (lbs) 18 (39.6)

Cutting group

n° of revs of drive shaft RPM 4700

drive shaft diameter mm (inch) 25,4 (1) *

max. diameter of cutting disc mm (inch) 406 (16)

max. cutting depth mm (inch) 140

Combustion engine

type Husqvarna, 2 stroke, single-cylinder, air cooled,

electronic start, 5-stage air fi lter

displacement

3

(cu.inch)

cm

bore / stroke mm (inch) 60 mm (2.36) / 42 mm (1.65)

power kW (HP) 5,8 (7.8)

n° of revs idling RPM min. 2700 - max. 9300 ± 150

tank capacity

litres (US Pint)

carburettor Walbro WG 9

spark plug CHAMPION RCJ6Y, NGK BPMR7A or equivalents

fuel petrol mixture

clutch centrifugal with automatic intervention

start by cord pull with automatic rewind

Acoustic noise

Vibration

(2)

(1)

dB L

2

m/s

105,5 (A) L

pA

119 (7.26)

1,25 (2.65)

121,3 (C) L

pCPeak

11,42 max.

WA

116 (A)

* If necessary it is possible to use abrasive discs with a 7/8 “(22.2 mm) fi xing hole (ref. to § 3.3.1 for details).

(1)

Directive 2006/42/EC, annexe 1, point 1.7.4.2 letter u

= weighted continuous acoustic pressure level equivalent.

L

pA

= maximum value of the weighted acoustic displacement pressure at the work place.

L

pCPeak

= acoustic power level emitted by the machine.

L

WA

(2)

Directive 2006/42/EC, annexe 1, point 2.2.1.1
Weighted root mean square in frequency of the acceleration the upper limbs are exposed to for each biodynamic
reference axis. Tests carried out in compliance with the indications contained in EN ISOS 5349-1/2 Standard, and
under operating conditions much more severe than those normally found.

6

3.2) Safety devices on the machine

ONLY FOR RDSC-20P TYPE: The rail saw must be started only when mounted on the
support arm otherwise the engine will be stopped by a cut-off device.

The safety devices supplied on the RAIL SAW and listed below must be fully functional and
checked before each use. If this is not the case do not use the machine and contact Cembre
for any repairs.

- ON/OFF SWITCH (18) this is found in a very visible
position and is easily operated. It is used for stopping
the machine normally or in emergency.

21

Ensure you are familiar with how to use the switch

(18) so that you can act promptly in case of emergency.

18

22

- ACCELERATOR (20): this is used to run the engine

to full operating speed. It can only be activated by
pressing the interlock lever at the same time (21).

- INTERLOCK LEVER (21): prevents accidental activation of the accelerator which can­ not be activate without pressing this lever.

When the accelerator is released, the abrasive cutting disc continues to turn for

some time. Do not approach the cutting group until the disc has completely stopped.

20

- ACCELERA TOR BLOCK (22): it locks the accelerator in start-up position when

the engine is cold. The accelerator block (22) can only be activated by
pressing the accelerator (20) and the interlock lever (21) at the same time.
Once activated, press the accelerator down.

start up position

- SAFETY GUARD (3) designed to protect the
operator from fragments and sparks which fl y off
during cutting. Push the handle forwards or
backwards to fi nd the most eff ective position.

Never use the RAIL SAW without the safety guard

or when the guard is damaged!

7

3

3.3) Abrasive cutting discs

For maximum performance, use the rail saw in conjunction with the high quality C-Rex range

Cembre discs listed below, in compliance with the requirements of the standard EN 12413 for
bonded abrasives.
Standard discs with 1 “(25.4 mm) mounting hole:

DISC
TYPE

Dimensions

diameter x thickness x hub

mm (inch)

(RPM)

CRDL4381 355x3.8x25.4 (14”x5/32”x1”) 5500 100 standard

CRDL6401 406x4.0x25.4 (16”x5/32”x1”) 4800 100 standard

Available discs with 7/8 “(22.2 mm) mounting hole:

CRDL4387 355x3.8x22.2 (14”x5/32”x7/8”) 5500 100 see § 3.3.1

CRDL6407 406x4.0x22.2 (16”x5/32”x7/8”) 4800 100 see § 3.3.1

– The RPM shown on the abrasive cutting disc label must be equal to or higher than that
produced by the rail saw.
– Never use the rail saw for grinding operations on the side surface of the disc, as it may break
and cause serious injury.
– The cutting discs must only be used for cutting suitable materials.
– During transportation and storage of the rail saw, always remove the cutting disc and lay
it on a fl at surface in a dry place protected from frost and moisture.
– Always tighten the fi xing screw of the cutting disc with a 20-25 Nm torque, to prevent
the disc from loosening.
– Worn or broken discs must be disposed of in compliance with local statutory requirements.

Peripheral

speed

(m/s)

Note

Always, use good quality cutting discs with a diameter
of 355 mm (14”) or 406 mm (16”) marked “RAIL” specifi c for
rail cutting.

The cutting disc may only be replaced when the engine

is switched off !

Never use cutting discs designed for a lower rpm than

that of the rail saw.

Never use a cutting disc beyond its expiration date, if

indicated.

Before using a cutting disc always check it is completely

free from damage.

A simple test for verifying the integrity of a cutting disc is to hold
it in the air and gently tap it with a screwdriver or a piece of wood;
an intact disc will produce a low drumming tone.

8

3.3.1) Use of 7/8 “abrasive cutting discs

The rail saw is designed to be used in combination with abrasive discs with a 1 “(25.4 mm)
mounting hole. If necessary it is possible remove the centering ring mounted on the shaft and
use discs with a 7/8 “(22.2 mm) mounting hole.

to use disc with 1 “(25.4 mm)
mounting hole.

centering ring
already mounted

Remove centering ring from
the hub to use disc with
7/8“(22.2 mm) mounting
hole.

hub

Removing the centering ring:

- Insert a fl at blade screwdriver into the
splitting (1) of the centering ring so as
to extend it and remove the ring from
the hub (2).

- To reassemble it, simply push the ring
on the hub until it stops.

ATTENTION: during the centering ring reassembly, the fl anged side must be
turned towards the support plate (D).

fl anged side

2

1

1

D

NO OK

NEVER USE CUTTING DISCS WITH A 1” (25.4 mm) HOLE WITHOUT CENTERING RING
MOUNTED ON THE SHAFT. THIS COULD CAUSE SERIOUS DAMAGE TO THE MACHINE AND
DANGER TO PERSONAL SAFETY.

9

4.1) Fuel mixture preparation

Risk of explosion or fi re, petrol is extremely fl ammable, handle with caution.
Risk of intoxication, avoid inhalation of petrol vapours.
Risk of irritation, avoid prolonged and repeated contact with skin.

The rail saw has a 2-stroke air cooled engine which runs on an oil-petrol mix; for the correct
dosage of oil use the measure supplied, according to the following proportions:

1:50 (2 %) of specialist synthetic 2 stroke engine oil (e.g. 5 litres of petrol,

0.1 litres of oil).
Alternatively:
1:33 (3 %) of other 2 stroke engine oils for air cooled engines classifi ed
according to JASO FB/ISO EGB (e.g. 5 litres of petrol, 0.15 litres of oil).

Always use good quality 2 stroke engine oil and a minimum 90 octane Petrol.

Mix petrol and oil together well and prepare only enough for immediate use as the mixture will
age and if several weeks old may cause engine damage.
Always use the correct fuel mixture to avoid:
1 - Smoking engine and dirty spark plug, should the mixture be too oil rich.
2 - Excessive overheating with consequent seizing of the engine, should the mixture be oil defi cient.

4.2) Refuelling

Always refuel with the engine switched off .
Place the rail saw on its side with the tank cap facing upwards.
Using a non-spill fuel container, slowly add the mix, making sure not to spill it;

Always perform refuelling in a well-ventilated area away from the work zone, keeping

a safe distance of at least 3 metres (10 ft).

Use only a non-spill fuel container.
In the event of spillage during topping up, carefully dry the engine before turning it on. Fully
tighten the fuel cap.

10

min. 3 m (10ft)

non-spill fuel
container

4.3) Mounting the cutting disc

WARNINGS:
– This operation must be performed with the engine switched off .
– Before using a cutting disc, always verify its compatibility with the rail saw
and observe the rules set out in § 3.4.
– Verify that the hub of the disc is perfectly suitable for the shaft.
– Always mount the disc complete with pressure plate.
– In order to avoid an overtightening of the screw (12), start the engine only when
the abrasive cutting disc is mounted.

– With the 13 mm multifunction spanner supplied, unscrew the locking screws (12) and
retrieve the pressure plate (S).
– Mount the disc on the shaft inside the safety guard so that
it rests on the central stop.
– Mount the pressure plate and lock
all the screws (12) tightening with
a 20-25 Nm.
During the tightening phase
counteract the movement.
of the disc with one hand.

1

2

S

20-25 Nm

11

12

4.4) Starting and stopping the engine

ONLY FOR RDSC-20P: Mount the rail saw on to the support
arm before starting the engine. It is not possible to start the engine
on the ground but only when the rail saw is mounted on the arm
otherwise an automatic cut-off device stops the engine!

Always start the machine at a safe distance from the refuelling

area.

Start the engine only when the abrasive cutting disc is mounted.

Before starting, check that the abrasive cutting disc can rotate

freely.

The rail saw can be started both on the ground and mounted on the
support arm. We advise that it is started on the ground fi rst to warm
it up, turned off and mounted on the support arm, then re-started.

– Turn the ignition switch to the left into the starting position (Fig. a).

– Press the decompression valve which makes start-up easier (Fig. b).

– Only when the engine is cold: fully pull the air valve control (Fig. c).
Completely press the accelerator, the interlock lever, the accelera­ tor block and then release the accelerator, it will lock in the starting
position (Fig. d).

Fig. a

click

Fig. b

Fig. c

Fig. d

– Gently pull the star ter cord until you feel some resistance (the starter

hooks will kick in) and then pull vigorously with rapid and decisive
movements until the engine starts (Fig. e).

NOTE:

To avoid damaging the winding device, accompany the starter

cord in the return phase and do not pull it over its stroke.

–

With the engine running, press and immediately release the acce-

lerator to unlock it from the starting position and let it run idle.

– Release the air valve control, if pulled.

– Keep the engine running for a few minutes to warm it up before star­ ting work.

Fig. e

12

• Ground star t-up, only for RDS-20P not for RDSC-20P (Fig. f):
To facilitate the starting operation, place one foot on the in
side of the rear handle in order to push the rail saw against

Fig. f

only for
RDS-20P

the ground and grasp the upper handle with one hand and.

–

Keep the engine running for a few minutes to warm it up before

starting work.

–

Tur n off the engine and mount the rail saw on the support arm.

Wait until the disc has completely stopped before

mounting the machine on the support arm.

– Restart the engine.

To stop the engine

– Release the accelerator and turn the ignition switch to the right into
the STOP position.

The SA-RDS support arm safely supports the rail saw in a comfortable position, which facilitates
fi xing and the starting of the engine. The rail saw needs to be guided during manual mode to
obtain a perfectly straight and perpendicular cut. Moreover, the operator can work unhindered
on both sides of the rail to take up the cut easily and precisely. The fi xing clamp is designed to
allow a precise and secure tightening of the arm on Vignole type rails.

255

350

320

13

210

265

1680

- Weight: 8.5 kg (18.7 lbs)

- Dimensions (mm):

112

3

2

1

6

Description:

1. Rail saw locking handle

2. Mobile arm

3. Sliding track

4. Clamp locking wheel/release

5. Cutting reference plate

6. Fixed jaw clamp

7. Stationary positioning lever

8. Knob to adjust arm height

9. Vertical arm

10. Mobile jaw clamp

11. Rail saw locking pin

9

7

7

xxxxxx

4

11

serial number

10

8

5

14

5.1) Attaching the support arm to the rail top

Open mobile jaw (6) by turning handwheel (7).
Rest the fi xing clamp on top of the rail head so that all four support teeth (Ref. Fig. a) touch the

rail. Tighten the fi xing clamp fi rmly with handwheel (Ref. Fig. b).

Before mounting the rail saw on the arm,
check that the clamp is positioned and locked
in a correct manner on the rail head (Ref. Fig. b).
If the arm is wrongly positioned, it can cause cut­ting which is not perfectly straight (Ref. Fig. c, d).

Fig. a

fi xing clamp

4 support

teeth

7

Fig. b

OK

Fig. c

NO

6

Fig. d

NO

NOTE: The fi xing clamp of the SA-RDS support arm is designed to allow a precise and secure
tightening of the arm on Vignole type rails; for fi xing the rail saw on most Girder type rails the
SAY1-RDS support arm is available.
For fi xing the rail saw on other diff erent rail types, please contact Cembre.

Vignole

type rail

15

Girder

type rail

other diff erent rail types, contact Cembre

5.2) Adjusting the height of the support arm

The SA-RDS support arm can be adjusted to
meet the cutting requirements based on the rail
dimensions and to allow the operator to adopt
a comfortable working position according to his
height.
There are 3 positions available; normally the

most suitable position is the one with knobs (8)
positioned centrally; to choose another position,

extract knobs (8) and move them into the upper
or lower slot.

Align knobs (8) in the same position to

avoid a cut which is not perfectly straight and
perpendicular to the rail.

5.3) Overturning the SA-RDS support arm

8

2

2

1

8

1

2

1

2

Overturning the arm must be carried out without the rail saw.

WARNING - Hand crushing hazard

The SA-RDS manual support arm can be
overturned from one side to the other
without needing to be removed from the
rail, to allow a comfortable and precise re­sumption of cutting.
To carry out this operation, it is suffi cient
to grasp it at point (A), rotate it by 180°
and move it so that it rests
on the opposite side; the re­ference (8) has to rest on the
clamp (6).

Before mounting the

rail saw on the arm, check
that lever (7) is correctly
inserted.

A

7

8

6

16

5.4) Mounting/dismounting the rail saw on the support arm

Before mounting the rail saw on the support arm, make sure that:

- the clamp (6) is fi rmly locked as described in § 5.1,

- the lever (7) is completely inserted

- the two knobs (8) are aligned at the same height.

7

11

1

1- Mount the rail saw on the support arm,
match the interface pin (11) with the slot of
the rail saw.
2- Push and rotate handle (1) tightening it fully.
To dismount the rail saw, completely loosen handle
(1) and remove it.

ONLY FOR RDSC-20P:

not mounted on the support arm (Ref. to § 3.2).

The fi gure shows the correct positioning of the rail saw on the support arm on both sides of the rail.

The engine will be stopped by a cut-off device if the rail saw is

2

1

8

6

17

The reference plate (5) is essential for exactly
locating the cutting line on the rail.
The length of the plate depends on the
machine-support arm assembly.
On the fi rst cut it is necessary to establish
an origin of the cutting distances by removing
excess plate:
– Fully rotate the plate (5) to 90°.
– Cut the rail (Ref. to § 7), the excess part of
the plate will be cut.
For subsequent, it will be possible to defi ne
the exact point at which the disc will touch
the rail and, therefore, to position the arm
at an appropriate distance, using the plate.

5

When not in use, or during transpor­tation of the arm turn the plate (5) inwards
to prevent its bending or damage.

Cutting line

closed position

open position

18

WARNINGS:

- Always consult your employer’s rules and procedures to cut rails in the presence of electri­ cal traction return current.

- Follow the precautions described in § 7.1.

- Ensure that everyone keeps the safety distance from the cutting zone.

- Remove aggregate (min. 15 cm) from the cutting area under the rail, to avoid
interference with the cutting disc guard and to make it easier to remove the disc when the
cut is fi nished.

– Fix the arm to the rail at the pre-esta­ blished point (Ref. to § 5.1)
NOTE: Check that the reference plate (5) is
totally turned; during the fi rst cut, the
origins of the cutting distances must be
defi ned exactly (Refer to § 6).
– Mount the rail saw onto the arm (Ref.

to § 5.4).
– Start the engine (Ref. to § 4.4).
– Support the rail saw by holding the upper
handle with one hand and with the other
hand pull out lever (7) locking it in the
external position to release the arm.
– Press the accelerator completely, slowly
bring the cutting disc towards the rail,
whilst respecting the precautions descri­ bed in § 7.1.

7

19

5

– Start the cut by using regular alter­ nate movements, maintaining a steady
pressure during the whole cutting phase.
The double articulation of the support arm
will relieve the operator of the weight of
the machine thus making the cutting
operation easier.

aggregate

min. 15 cm

– Once the operation is fi nished, release the accelerator, lift the
rail saw and re-lock the arm in its resting position by pushing
in the lever (7) fully .
– Switch off the engine by using the switch (18) and wait for the
disc to completely stop turning before carrying out any further
interventions.

NOTE: Some factors such as the diameter of the cutting disc, a partially worn disc and the rail
dimensions, can infl uence the cutting operation and prevent the execution of a full cut. In such
a case, the arm will have to be overturned (Ref. to § 8.3) and the process completed by taking
up the cut on the opposite side.

18

Taking up
procedure

20

7.1) Dangers deriving from the cutting process

• How to avoid kickback

Kickback may cause fatal injuries.

When using the machine in manual mode, during the phase of approaching the rail, ensure that
the contact between the disc and the rail does not occur in the disc’s upper quadrant (“risk of
kickback zone”), as this may cause a sudden and unexpected reaction from the machine which
would be thrown towards the operator, with possible serious consequences for safety.

To avoid such a reaction, follow the rules outlined below:

– The cutting operation must never start in the upper
quadrant of the cutting disc (see fi gure).
– While working, stand in a safe and stable position
and grasp the handle fi rmly.
– Approach the rail carefully at the start of the cutting
operation.
– With a cut that has already been started, insert the
disc very carefully at maximum speed.

• Pull in
Pull in occurs when the cutting disc catches
unexpectedly during operation and the rail saw is
violently pulled downwards; this can happen if the
cut closes and the disc jams.
To avoid pull in, ensure that the cut stays open
during the whole process. Check that the rail saw
is stable or resting on supports placed as illustrated
in the lower, on the right.

• Overturning

Ensure that the rail is stable or is resting on solid
supports.
Attach the arm on the stable side of the rail.
To cut short rail sections, the section must be sta­bilised with appropriate fi xtures to avoid the risk
of unexpected machine movement; the stabilising
support Cembre type SSR1 fulfi ls this function and
is available as an accessory.

21

SSR 1

stabilising support

Daily maintenance is indispensable to keep the rail saw in best condition. Maintenance not
carried out properly, or carried out by unauthorised or unqualifi ed personnel can noticeably
reduce the machine’s effi ciency and increase the risk of accidents and serious injury.
The maintenance procedures described may be carried out by the operator.
For any eventual fi ne tuning or repairs, return to Cembre.
The maintenance plan provided is intended for a machine which is used daily, so intervals may
vary according to usage frequency.

_________________________ MAINTENANCE PLAN ___________________________

• Daily

Before using, check:

– The whole machine and support arms (the fi xing of the various components).
– The safety equipment is working properly and is not damaged: the ON-OFF
switch, accelerator, interlock lever, accelerator block, the disc guard.
– The cutting disc is not damaged.

After usage:

– Clean the machine and support arms with a clean rag to remove dust and cutting waste.
– Clean the ventilation openings situated on the transmission side cover.

• Weekly

Check:

– The fi xing of the muffl er.
– The state and wear of the drive belt (Refer to § 8.8)
– The carburettor is working.
– The start-up devices (cable, counter spring).
– Clean the cooling fi ns on the cylinder.
– The sponge fi lter in the transmission cover.

• Monthly

Check:

– Clutch wear.
– The carburettor fi lter, change it if necessary.
– The various cables and fi tting of the supply system.

Clean

:
– The spark plug; change it if necessary (Refer to § 8.3).
– The outside of the carburettor.
– The interior of the tank.

22

The air fi lters and drive belt require constant maintenance to keep the rail saw in best condition:

OPERATING TIME OPERATIONS TO BE PERFORMED

Check the wear of the drive belt.

After 1 HOUR

After 3 HOURS

Clean:

• engine air fi lters (Ref. to § 8.1)

• cover fi lter (Ref. to § 8.7)

Replace:

• drive belt (Ref. to § 8.8)

• engine air fi lters (Ref. to § 8.1)

Clean:

• cover fi lter (Ref. to § 8.7)

NOTE: The scheduled maintenance of the air fi lter is established for the standard operation
of the machine in well-ventilated spaces outdoors. In closed and particularly dusty spaces,

cleaning or changing the fi lters more frequently may be necessary, especially if starting­up the engine is diffi cult or if there is a reduction in power.

8.1) Engine fi lter cleaning

The engine’s fi lter system comprises a primary fi lter (S) and a
secondary paper fi lter (P).
Not maintaining the fi lters properly can cause:
– Diffi cult or impossible start-up of the engine
– Reduction in engine power.
– High consumption.
– Carburettor malfunction.
– Unnecessary wear on engine parts.
– Deposits on the spark plug.
– The machine not being able to carry out cutting
in automatic mode.

• Primary sponge fi lter (S) (spare part code: 6003910)
– Remove the top engine cover by unscrewing the 2
Torx screws with the tool supplied.
– Take the fi lter out and wash it carefully with warm
water and soap, then rinse it well with clean water.
Squeeze the fi lter well and dry it.
– Before remounting it, carefully oil the fi lter.
It is important that the fi lter is well-oiled, in order
to do this we advise putting it in a bag, adding oil,
spreading it evenly over the fi lter then squeezing it
to get rid of excess oil.
Do not use normal engine oil for this purpose,
contact Cembre for suitable oil.

Engine cover

S

P

S

Insert

P

NOTE: Do not clean the fi lter with compressed air as

high pressure could damage the sponge.

23

• Paper Filter (P) (spare part code: 6003911)
– Remove the insert, take the fi lter out and shake or clean it carefully
with compressed air from the inside out, to remove the dust.
– Reassemble correctly.

NOTE: the paper fi lter must not be washed!

Depending on usage, the fi lter will have to be periodically
replaced with a new one.
A damaged air fi lter must be replaced immediately.

8.2) Fuel fi lter (spare part code: 6003922)

A reduction in fuel fl ow towards the carburettor indicates that the fi lter is clogged up.
The fuel fi lter is located in the fuel tank and if it is clogged up, it must be replaced with a new
one as it cannot be cleaned.

Avoid dirt getting into the fuel tank during fi lter replacements.
Replace the fuel fi lter at least once a year.

8.3) Spark plug (spare part code: 6003752)

Deposits on the spark plug’s electrode can cause malfunctions or engine start-up problems. This
can be due to:
– A mix of fuel that contains too much oil.
– A dirty air fi lter.
– A carburettor that is not regulated properly.
To clean the spark plug:
– Remove the uppermost engine cover by unscrewing the two side screws.
– Disconnect the coil and unscrew the spark plug with the wrench supplied.
– Clean off all the deposits on the electrode using a wire brush, taking care
not to damage the ceramic support.
– Check, and if necessary, adjust the distance of the electrodes to 0,5 mm.
– Screw the spark plug back in, reconnect the lead and remount the cover.
– If a replacement is needed, use CHAMPION RCJ6Y, NGK BPMR7A or equivalent.

An unsuitable spark plug can damage the cylinder or the piston.
Replace the spark plug after about a month of work, or more often if necessary.

24

8.4) Carburettor

The carburettor regulates engine speed through the accelerator and blends air and fuel together.
The rail saw’s engine is regulated during manufacture so that harmful emissions are reduced
to a minimum.

The complete running in of the engine is achieved after having topped up the fuel tank
8-10 times.
Avoid adjusting the carburettor unless absolutely necessary.

• Main nozzle
The engine is equipped with a fi xed nozzle that ensures the correct supply of the blended air
and fuel. If the engine is losing power or is not accelerating, clean or if necessary replace the air
fi lter. If this does not resolve the problem, contact Cembre.

L

T

• Carburettor adjustment
Fully press the accelerator a couple of times and check
that the rail saw accelerates as expected.

T

L

• Final adjustment of minimum speed T
The engine’s minimum speed is adjusted through screw T. If an adjustment is required, turn
clockwise until the cutting disc starts to turn, then slowly turn anticlockwise until the disc stops
turning. The minimum speed is adjusted correctly when the engine accelerates correctly.
Minimum rpm advised: 2700 rpm.

The cutting disc must remain still at minimum speed.

Screw L is factory set open by 1 and a 1/4 turns. If an
adjustment is necessary, turn it clockwise until there is
no fuel in the engine; then open it 1/8 turn anticlockwise.
Check engine acceleration.
NOTE: A poor adjustment of low speed (screw L too
tight) can cause diffi culty when starting the engine.

8.5) Exhaust Muffl er

Burns risk!

The muffl er has been designed to reduce noise levels
and to channel exhaust fumes away from the operator.
Check the muffl er and its fi xings regularly to ensure
there is no damage.
Exhaust fumes are hot and can contain sparks which
may set fi re to dry and fl ammable material anywhere
near the machine.

Never use the machine with a muffl er that is clogged
or faulty.

25

8.6) Starter cord

Always wear safety goggles when replacing the starter cord; the recoil spring is tensio-

ned and if accidentally released may cause personal injury!

• Replacing a worn or broken starter cord

– Unscrew 4 screws that hold the side motor cover and
remove it (Ref. to Fig. a).
– Pull out approx. 30 cm of cord by drawing it across the
notch on the side of the pulley.
Release the tension of the spring by making the pulley
rotate slowly (Ref. to Fig. b).
– Unscrew the pulley’s fastening screws and lift it.
– Thread the new cord through the cavity in the pulley and
attach the cord with a knot, wind the cord clockwise 3
or 4 times around the cavity (Ref. to Fig. c).
– Put the pulley back onto the recoil spring so that the
end of the spring clasps the pulley and re-attach with
the screw in the centre.
– Thread the starter cord through the hole in the side cover
and the starter handle. Make a knot at the end of the cord
(Refer to Fig. d).

• Tensioning the recoil spring

– Remove the starter cord through the notch on the side of
the pulley and rotate the pulley by approx. 2 clockwise rota­ tions (Ref. to Fig. e); check that the pulley can rotate

by a further 1/2 rotation with the cord fully extended.

Fig. a

Fig. b

• Assembling the side cover of the ignition device

– Pull the starter cord and rest the cover on the motor’s side
(Ref. to Fig. f).
– Release the starter cord slowly so that the pawls slot into
the pulley.
– Screw the 4 engine cover screws back into place.

Fig. f

Fig. c

Fig. e

Fig. d

26

• Replacing the recoil spring

– Remove the starter pulley by unscrewing the central screw.
– Remove the recoil spring carefully by grasping it with grips.
– Lubricate the recoil spring with a few drops of oil and then reassemble the starter pulley
and tension the spring.
If the spring pops out during the assembly phase, it will have to be reassembled again
from the exterior towards the centre.

8.7) Transmission cooling system

The ventilation openings situated on the side cover allow the
suction of fresh air and its expulsion so that the transmission
system, including the belt, can be cooled.
After use and on a daily basis it is good practice
to check that these openings are perfectly cle­an. If necessary, clean them with compressed
air or a soft brush.
The fi lter on the lower part of the cover
prevents cutting particles and debris being
conveyed inside the transmission area.

8.7.1) Cleaning the transmission fi lter

(spare part code: 6003655)
– Disassemble the side cover by removing
5 screws with the 4 mm Allen key supplied.
– Remove the fi lter and shake or clean it
with compressed air, to remove dirt.
– Relocate and reassemble the cover.

Side
cover

Air intake (suction) from outside

A clogged fi lter can cause abnormal
overheating of the belts resulting in pre­mature wear.

In any case, depending on usage, the fi lter
will have to be replaced periodically with a
new one.

Transmission fi lter

IMPORTANT: When cleaning the fi lter, clean also the inte­rior of the transmission area and the two turbine wheels,
with compressed air; check the status of the drive belt,

if it is worn it’s essential to replace it.

27

Transmission fi lter

8.8) Replacing the drive belt (spare part code: 6003787)

1

2

Drive belt must be replaced if worn out.

The process is easier with a cutting disc fi tted:
– Disassemble the side cover (Ref. to § 8.7.1).
– Unscrew screw (V), remove the fan group (GA) and unthread the worn belt.

1 Place the belt on the drive shaft pulley, behind the rear pinion.
2 Thread it behind plate (P) and under rolls (R) and place it against the front split pulley.

– Assemble the fan group, polarizing it with respect to the two faces of the drive shaft
and lightly tighten the screw (V) into place.
NOTE: During reassembly, fi rstly manually
alternate blocking and rotation of the disc.
This will counter the rotation of the drive
shaft produced by the two split pulleys
getting closer.
Secondly, the correct radial position of the
belt must be obtained with respect to the
internal surfaces of the split pulleys so that
the belt runs towards the exterior.
– Tighten screw (V) 50 Nm.
– Reassemble the side cover.

Drive

belt

(P)

(V)

(R)

WARNING: During the Fan
group (GA) reassembly phase,
the belt absolutely must NOT be
compressed between the two split
pulleys, but should run towards the
exterior to avoid being deformed.

Split pulleys

(GA)

28

During transport or storage of the machine always remove the cutting disc.

2

1

To facilitate transport and protect the Rail Saw, support arms and accessories from accidental
knocks and dirt, Cembre recommends the use of appropriate container, robust wooden crate
with convenient spaces.
VAL-RDS container: for storing the Rail Saw, cutting discs and the support arm.
Dimensions 1000 x 390 x h550 mm (39.3 x 15.3 x 21.6 in.), weight 12 kg (26.4 lbs).
If transporting the machine or if it is not used for a long period of time, empty the fuel tank and
store the machine in a dry and safe place which is not accessible to children or unauthorised
persons.
During transportation and storage of the rail saw, always remove the cutting disc and lay it on
a fl at surface in a dry place protected from frost and moisture.

Correct storing of Rail Saw
and Support arm into the
cases.

RDS...

SA-RDS

VAL-RDS

29

SYMPTOM

CAUSE

REMEDY

- Engine diffi cult to start:

- Engine does not start
(only for RDSC-20P):

- Engine stops while in use:

- Overheating with possible
seizure of engine:

- Too much exhaust smoke:

Switch (18) in “STOP” position.

No fuel.

Air lever in wrong position

Fuel fi lter clogged.

Air fi lter clogged.

Spark plug dirty from residue.

Bad fuel mixture.

incorrect carburettor adjustment

the rail saw is not mounted on the
support arm.

No fuel.

Air or fuel fi lters clogged.

Bad fuel mixture.

Insuffi cient oil in fuel mixture.

Obstructed cooling fi ns.

Too much oil in fuel mixture.

Move switch to “START” position.

Add fuel to tank (see § 4.2).

Check position (see § 4.4)

Check and if necessary replace (see § 8.2).

Clean and if necessary replace (see § 8.1).

Clean and if necessary replace (see § 8.3).

Prepare fuel mixture correctly (see § 4.1).

Check the carburettor adjustment (§ 8.4).

Mount the rail saw on to the support arm (see § 3.2).
before starting the engine.

Add fuel to tank (see § 4.2).

Clean, if necessary replace (see § 8 .1 8.2).

Prepare fuel mixture correctly (see § 4.1).

Prepare mixture with more oil.

Clean the cooling fi ns.
Check engine for seizure, contact Cembre (§ 11).

Prepare mixture with less oil.
Clean spark plug, if necessary (§ 8.3).

- Cutting capacity too low:

Worn belt.

Air or fuel fi lters clogged.

Check the wear and tear (§ 8.6).

Clean, if necessary replace (see § 8 .1 and 8.2).

30

In the case of a breakdown contact our Area Agent who will advise you on the problem and give
you the necessary instructions on how to dispatch the machine to our nearest service Centre; if
possible, attach a copy of the Test Certifi cate supplied by Cembre together with the machine
or fi ll in and attach the form available in the “ASSISTANCE” section of the Cembre website.

FIG. 2 RAIL SAW DIMENSIONS mm (inches)

448 (17.6)

280 (11)

31

max. 858 (33.7)

ø 400 mm

815 (32)

max. 959 (37.7)

Cembre S.p.A.

Via Serenissima, 9
25135 Brescia (Italia)
Telefono: 030 36921
Telefax: 030 3365766
E-mail: [e-mail]
www.cembre.com

Cembre España S.L.U.

Calle Verano 6 y 8
28850 Torrejón de Ardoz
Madrid (España)
Teléfono: 91 4852580 - Fax: [phone]
E-mail: [e-mail]
www.cembre.es

www.cembre.com

Cembre Ltd.

Dunton Park
Kingsbury Road, Curdworth - Sutton Coldfield
West Midlands B76 9EB (UK)
Tel.: [phone] - Fax: [phone]
E-mail: [e-mail]
www.cembre.co.uk

Cembre GmbH

Heidemannstraße 166
80939 München (Deutschland)
Telefon: [phone]
Telefax: 089 35806777
E-mail: [e-mail]
www.cembre.de

IKUMA GmbH & Co. KG

Boschstraße 7
71384 Weinstadt (Deutschland)
Telefon: [phone]
Telefax: 7151 20536-80
E-mail: [e-mail]
www.ikuma.de

Cembre S.a.r.l.

22 Avenue Ferdinand de Lesseps
91420 Morangis (France)
Tél.: [phone] - Fax: [phone]
CS 92014 - 91423 Morangis Cédex
E-mail: [e-mail]
www.cembre.fr

Cembre Inc.

Raritan Center Business Park
181 Fieldcrest Avenue
Edison, New Jersey 08837 (USA)
Tel.: [phone] - Fax: [phone]
E-mail: [e-mail]
www.cembreinc.com

any reproduction is forbidden without written permission.

Cembre:

This manual is the property of

cod. 6261485

32