Makita SG1251 User manual

1
ENGLISH (Original instructions)
INSTRUCTION MANUAL
DOUBLE INSULATION
IMPORTANT: Read Before Using.
Wall Chaser
SG1251
015035

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ENGLISH (Original instructions)
SPECIFICATIONS
Model SG1251
Wheel diameter 125 mm
Max. wheel thickness 2.1 mm
Rated speed 10,000 min-1
Spindle thread M14
Overall length 350 mm
Net weight 4.5 kg
Safety class /II
• Due to our continuing program of research and development, the specifications herein are subject to change without notice.
• Specifications may differ from country to country.
• Weight according to EPTA-Procedure 01/2003
END202-8
Symbols
The following show the symbols used for the equipment.
Be sure that you understand their meaning before use.
･Read instruction manual.
･DOUBLE INSULATION
･Wear safety glasses.
･Only for EU countries
Do not dispose of electric equipment
together with household waste
material!
In observance of the European
Directive, on Waste Electric and
Electronic Equipment and its
implementation in accordance with
national law, electric equipment that
have reached the end of their life must
be collected separately and returned to
an environmentally compatible
recycling facility.
ENE026-1
Intended use
The tool is intended for cutting tracks in concrete walls
or cutting in ferrous materials or concrete drainage
channels with a diamond wheel but without using water.
ENF002-2
Power supply
The tool should be connected only to a power supply of
the same voltage as indicated on the nameplate, and
can only be operated on single-phase AC supply. They
are double-insulated and can, therefore, also be used
from sockets without earth wire.
ENG905-1
Noise
The typical A-weighted noise level determined
according to EN60745:
Sound pressure level (LpA) : 97 dB (A)
Sound power level (LWA) : 108 dB (A)
Uncertainty (K) : 3 dB (A)
Wear ear protection
ENG900-1
Vibration
The vibration total value (tri-axial vector sum)
determined according to EN60745:
Work mode : concrete cutting
Vibration emission (ah) : 5.0 m/s2
Uncertainty (K) : 1.5 m/s2
ENG901-1
• The declared vibration emission value has been
measured in accordance with the standard test
method and may be used for comparing one tool
with another.
• The declared vibration emission value may also be
used in a preliminary assessment of exposure.
WARNING:
• The vibration emission during actual use of the
power tool can differ from the declared emission
value depending on the ways in which the tool is
used.
• Be sure to identify safety measures to protect the
operator that are based on an estimation of
exposure in the actual conditions of use (taking
account of all parts of the operating cycle such as
the times when the tool is switched off and when it
is running idle in addition to the trigger time).

3
ENH101-18
For European countries only
EC Declaration of Conformity
Makita declares that the following Machine(s):
Designation of Machine:
Wall Chaser
Model No./ Type: SG1251
Conforms to the following European Directives:
2006/42/EC
They are manufactured in accordance with the following
standard or standardized documents:
EN60745
The technical file in accordance with 2006/42/EC is
available from:
Makita, Jan-Baptist Vinkstraat 2, 3070, Belgium
7.2.2014
000331
Yasushi Fukaya
Director
Makita, Jan-Baptist Vinkstraat 2, 3070, Belgium
GEA005-3
General Power Tool Safety
Warnings
WARNING Read all safety warnings and all
instructions. Failure to follow the warnings and
instructions may result in electric shock, fire and/or
serious injury.
Save all warnings and
instructions for future reference.
The term "power tool" in the warnings refers to your
mains-operated (corded) power tool or battery-operated
(cordless) power tool.
Work area safety
1. Keep work area clean and well lit. Cluttered or
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.
Electrical safety
4. Power tool plugs must match the outlet. Never
modify the plug in any way. Do not use any
adapter plugs with earthed (grounded) power
tools. Unmodified plugs and matching outlets will
reduce risk of electric shock.
5. Avoid body contact with earthed or grounded
surfaces such as pipes, radiators, ranges and
refrigerators. There is an increased risk of
electric shock if your body is earthed or grounded.
6. Do not expose power tools to rain or wet
conditions. Water entering a power tool will
increase the risk of electric shock.
7. Do not abuse the cord. Never use the cord for
carrying, pulling or unplugging the power tool.
Keep cord away from heat, oil, sharp edges or
moving parts. Damaged or entangled cords
increase the risk of electric shock.
8. When operating a power tool outdoors, use an
extension cord suitable for outdoor use. Use
of a cord suitable for outdoor use reduces the risk
of electric shock.
9. If operating a power tool in a damp location is
unavoidable, use a residual current device
(RCD) protected supply. Use of an RCD
reduces the risk of electric shock.
10. Use of power supply via a RCD with a rated
residual current of 30mA or less is always
recommended.
Personal safety
11. 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 serious
personal injury.
12. Use personal protective equipment. Always
wear eye protection. Protective equipment such
as dust mask, non-skid safety shoes, hard hat, or
hearing protection used for appropriate conditions
will reduce personal injuries.
13. Prevent unintentional starting. Ensure the
switch is in the off-position before connecting
to power source and/or battery pack, picking
up or carrying the tool. Carrying power tools
with your finger on the switch or energising power
tools that have the switch on invites accidents.
14. Remove any adjusting key or wrench before
turning the power tool on. A wrench or a key
left attached to a rotating part of the power tool
may result in personal injury.
15. Do not overreach. Keep proper footing and
balance at all times. This enables better control
of the power tool in unexpected situations.
16.
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.

4
17. If devices are provided for the connection of
dust extraction and collection facilities,
ensure these are connected and properly
used. Use of dust collection can reduce dust-
related hazards.
Power tool use and care
18. 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 for which it was designed.
19. 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.
20. Disconnect the plug from the power source
and/or the battery pack from the power tool
before making any adjustments, changing
accessories, or storing power tools. Such
preventive safety measures reduce the risk of
starting the power tool accidentally.
21. Store idle power 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.
22. Maintain power tools. Check for misalignment
or binding of moving parts, breakage of parts
and any other condition that may affect the
power tool’s operation. If damaged, have the
power tool repaired before use. Many
accidents are caused by poorly maintained power
tools.
23. Keep cutting tools sharp and clean. Properly
maintained cutting tools with sharp cutting edges
are less likely to bind and are easier to control.
24. Use the power tool, accessories and tool bits
etc. in accordance with these instructions,
taking into account the working conditions
and the work to be performed. Use of the
power tool for operations different from those
intended could result in a hazardous situation.
Service
25. Have your power tool serviced by a qualified
repair person using only identical
replacement parts. This will ensure that the
safety of the power tool is maintained.
26. Follow instruction for lubricating and
changing accessories.
27. Keep handles dry, clean and free from oil and
grease.
GEB112-6
WALL CHASER SAFETY
WARNINGS
1. The guard provided with the tool must be
securely attached to the power tool and
positioned for maximum safety, so the least
amount of wheel is exposed towards the
operator. Position yourself and bystanders
away from the plane of the rotating wheel. The
guard helps to protect operator from broken
wheel fragments and accidental contact with
wheel.
2. Use only diamond cut-off wheels for your
power tool. Just because an accessory can be
attached to your power tool, it does not assure
safe operation.
3. The rated speed of the accessory must be at
least equal to the maximum speed marked on
the power tool. Accessories running faster than
their rated speed can break and fly apart.
4. Wheels must be used only for recommended
applications. For example: do not grind with
the side of cut-off wheel. Abrasive cut-off
wheels are intended for peripheral grinding, side
forces applied to these wheels may cause them
to shatter.
5. Always use undamaged wheel flanges that are
of correct diameter for your selected wheel.
Proper wheel flanges support the wheel thus
reducing the possibility of wheel breakage.
6. The outside diameter and the thickness of
your accessory must be within the capacity
rating of your power tool. Incorrectly sized
accessories cannot be adequately guarded or
controlled.
7. The arbour size of wheels and flanges must
properly fit the spindle of the power tool.
Wheels and flanges with arbour holes that do not
match the mounting hardware of the power tool
will run out of balance, vibrate excessively and
may cause loss of control.
8. Do not use damaged wheels. Before each use,
inspect the wheels for chips and cracks. If
power tool or wheel is dropped, inspect for
damage or install an undamaged wheel. After
inspecting and installing the wheel, position
yourself and bystanders away from the plane
of the rotating wheel and run the power tool at
maximum no load speed for one minute.
Damaged wheels will normally break apart during
this test time.

5
9. Wear personal protective equipment.
Depending on application, use face shield,
safety goggles or safety glasses. As
appropriate, wear dust mask, hearing
protectors, gloves and shop apron capable of
stopping small abrasive or workpiece
fragments. The eye protection must be capable
of stopping flying debris generated by various
operations. The dust mask or respirator must be
capable of filtrating particles generated by your
operation. Prolonged exposure to high intensity
noise may cause hearing loss.
10. Keep bystanders a safe distance away from
work area. Anyone entering the work area
must wear personal protective equipment.
Fragments of workpiece or of a broken wheel
may fly away and cause injury beyond immediate
area of operation.
11. Hold the power tool by insulated gripping
surfaces only, when performing an operation
where the cutting accessory may contact
hidden wiring or its own cord. Cutting
accessory contacting a "live" wire may make
exposed metal parts of the power tool "live" and
could give the operator an electric shock.
12. Position the cord clear of the spinning
accessory. If you lose control, the cord may be
cut or snagged and your hand or arm may be
pulled into the spinning wheel.
13. Never lay the power tool down until the
accessory has come to a complete stop. The
spinning wheel may grab the surface and pull the
power tool out of your control.
14. Do not run the power tool while carrying it at
your side. Accidental contact with the spinning
accessory could snag your clothing, pulling the
accessory into your body.
15. Regularly clean the power tool’s air vents. The
motor’s fan will draw the dust inside the housing
and excessive accumulation of powdered metal
may cause electrical hazards.
16. Do not operate the power tool near flammable
materials. Sparks could ignite these materials.
17. Do not use accessories that require liquid
coolants. Using water or other liquid coolants
may result in electrocution or shock.
Kickback and related warnings
Kickback is a sudden reaction to a pinched or snagged
rotating wheel. Pinching or snagging causes rapid
stalling of the rotating wheel which in turn causes the
uncontrolled power tool to be forced in the direction
opposite of the wheel’s rotation at the point of the
binding.
For example, if an abrasive wheel is snagged or
pinched by the workpiece, the edge of the wheel that is
entering into the pinch point can dig into the surface of
the material causing the wheel to climb out or kick out.
The wheel may either jump toward or away from the
operator, depending on direction of the wheel’s
movement at the point of pinching. Abrasive wheels
may also break under these conditions.
Kickback is the result of power tool misuse and/or
incorrect operating procedures or conditions and can be
avoided by taking proper precautions as given below.
a) Maintain a firm grip on the power tool and
position your body and arm to allow you to
resist kickback forces. Always use auxiliary
handle, if provided, for maximum control over
kickback or torque reaction during start-up.
The operator can control torque reactions or
kickback forces, if proper precautions are taken.
b) Never place your hand near the rotating
accessory. Accessory may kickback over your
hand.
c) Do not position your body in line with the
rotating wheel. Kickback will propel the tool in
direction opposite to the wheel’s movement at the
point of snagging.
d) Use special care when working corners,
sharp edges etc. Avoid bouncing and snagging
the accessory. Corners, sharp edges or bouncing
have a tendency to snag the rotating accessory
and cause loss of control or kickback.
e) Do not attach a saw chain, woodcarving
blade, segmented diamond wheel with a
peripheral gap greater than 10 mm or toothed
saw blade. Such blades create frequent kickback
and loss of control.
f) Do not “jam” the wheel or apply excessive
pressure. Do not attempt to make an excessive
depth of cut. Overstressing the wheel increases
the loading and susceptibility to twisting or binding
of the wheel in the cut and the possibility of
kickback or wheel breakage.
g) When wheel is binding or when interrupting
a cut for any reason, switch off the power tool
and hold the power tool motionless until the
wheel comes to a complete stop. Never
attempt to remove the wheel from the cut while
the wheel is in motion otherwise kickback may
occur. Investigate and take corrective action to
eliminate the cause of wheel binding.
h) Do not restart the cutting operation in the
workpiece. Let the wheel reach full speed and
carefully re-enter the cut. The wheel may bind,
walk up or kickback if the power tool is restarted in
the workpiece.

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i) Support panels or any oversized workpiece
to minimize the risk of wheel pinching and
kickback. Large workpieces tend to sag under
their own weight. Supports must be placed under
the workpiece near the line of cut and near the
edge of the workpiece on both sides of the wheel.
j) Use extra caution when making a “pocket
cut” into existing walls or other blind areas.
The protruding wheel may cut gas or water pipes,
electrical wiring or objects that can cause kickback.
18. Before using a segmented diamond wheel,
make sure that the diamond wheel has the
peripheral gap between segments of 10 mm or
less, only with a negative rake angle.
Additional Safety Warnings:
19. Never attempt to cut with the tool held upside
down in a vise. This can lead to serious
accidents, because it is extremely dangerous.
20. Some material contains chemicals which may
be toxic. Take caution to prevent dust
inhalation and skin contact. Follow material
supplier safety data.
21. Store wheels as per manufacturer
recommendations. Improper storage may
damage the wheels.
SAVE THESE INSTRUCTIONS.
WARNING:
DO NOT let comfort or familiarity with product
(gained from repeated use) replace strict adherence
to safety rules for the subject product. MISUSE or
failure to follow the safety rules stated in this
instruction manual may cause serious personal
injury.
FUNCTIONAL DESCRIPTION
CAUTION:
• Always be sure that the tool is switched off and
unplugged before adjusting or checking function
on the tool.
Shaft lock
CAUTION:
• Never actuate the shaft lock when the spindle is
moving. The tool may be damaged.
1
015036
Press the shaft lock to prevent spindle rotation when
installing or removing accessories.
Sighting
1
004497
There are notches on the front and rear of the base.
This is helpful for an operator to follow a straight cutting
line.
Adjusting the grooving depth
1
2
015077
The grooving depth can be adjusted between 0 mm and
30 mm.
Loosen the clamping screw and adjust the pointer to
your desired depth graduation on the scale.
Then tighten the clamping screw firmly.
1. Scale
2. Clamping screw
1. Notch
1. Shaft lock

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Switch action
CAUTION:
• Before plugging in the tool, always check to see
that the switch trigger actuates properly and
returns to the "OFF" position when released.
2
1
015038
For tool with lock button
CAUTION:
• Switch can be locked in "ON" position for ease of
operator comfort during extended use. Apply
caution when locking tool in "ON" position and
maintain firm grasp on tool.
To start the tool, simply pull the switch trigger. Release
the switch trigger to stop.
For continuous operation, pull the switch trigger, push in
the lock button and then release the switch trigger.
To stop the tool from the locked position, pull the switch
trigger fully, then release it.
For tool with lock-off button
CAUTION:
• Do not pull the switch trigger hard without pressing
in the lock-off button. This can cause switch
breakage.
To prevent the switch trigger from being accidentally
pulled, a lock-off button is provided.
To start the tool, depress the lock-off button and pull the
switch trigger. Release the switch trigger to stop.
For tool without lock button / lock-off button
To start the tool, simply pull the switch trigger. Release
the switch trigger to stop.
Electronic function
The tools equipped with electronic function are easy to
operate because of the following features.
Constant speed control
Electronic speed control for obtaining constant speed.
Possible to get fine finish, because the rotating speed is
kept constant even under load condition.
Soft start
Soft-start feature minimizes start-up shock, and makes
the tool start smoothly.
Overload protector
When the tool would be employed over the admissible
load, it will stop automatically to protect the motor and
wheel. When the load will come to the admissible level
again, the tool can be started automatically.
ASSEMBLY
CAUTION:
• Always be sure that the tool is switched off and
unplugged before carrying out any work on the
tool.
Removing the diamond wheels
1
015039
Loosen and remove the bolt with the hex wrench.
1
2
015040
Open the blade case while holding the tool base.
NOTE:
• The tool base will open at a stroke by the spring
force.
12
3
015053
Rotate the diamond wheels while pressing the shaft lock
until it engages.
Remove the lock nut by rotating it counterclockwise with
the lock nut wrench.
Remove the diamond wheels and space rings.
1. Shaft lock
2. Lock nut
3. Lock nut wrench
1. Blade case
2. Tool base
1. Bolt
1. Switch trigger
2. Lock button /
Lock-off button

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Adjusting the groove width (the distance
between the two diamond wheels)
Adjust the grooving width by changing the number of
the space rings as shown in the table.
12
3
4
5
Groove width: 30 mm
Groove width: 18 mm Groove width: 15 mm
Groove width: 27 mm
Groove width: 24 mm
Groove width: 9 mm
Groove width: 6 mm
Groove width: 21 mm
Groove width: 12 mm
004503
Installing the diamond wheels
12
3
015054
Mount the diamond wheel carefully onto the spindle.
Align the directions of the arrow on the diamond wheel
and the tool. Install space rings, the other diamond
wheel and the lock nut.
Tighten the lock nut securely clockwise with the lock nut
wrench while pressing the shaft lock.
1
2
015047
Return the blade case and tool base to the original
position and tighten the bolt to secure them.
Adjusting the front handle angle
1
2
015042
Loosen the two bolts on both sides of the front handle
with the hex wrench. Move the front handle to your
desired angle and tighten the two bolts firmly.
NOTE:
• When the handle cannot be moved easily, loosen
the bolts furthermore.
Shifting the front handle sideways
1
1
22
3
015043
Remove the two bolts on both sides of the front handle
with the hex wrench. Change the position of the cam.
Insert the longer bolt to the side close to the cam and
the shorter one to the opposite side. Tighten the two
bolts firmly.
1. Bolt (Short)
2. Cam
3. Bolt (Long)
1. Front handle
2. Bolt
1. Blade case
2. Diamond wheel
1. Shaft lock
2. Lock nut
3. Lock nut wrench
1. Lock nut
2. Diamond wheel
3. Space ring 6 (6 mm thick)
4. Space ring 3 (3 mm thick)
5. Diamond wheel

9
Connecting to vacuum cleaner
1
2
3
015046
When using Makita dust collector, connect the hose for
the vacuum cleaner directly to the dust nozzle.
NOTE:
• The dust nozzle can be rotated freely so that you
can use it at any angle according to your operation.
Hex wrench storage
1
2
004508
When not in use, store the hex wrench to keep it from
being lost.
OPERATION
CAUTION:
• Be sure to pull the tool when cutting a workpiece.
• Use this tool for straight line cutting only. Cutting
curves can cause stress cracks or fragmentation
of the diamond wheels resulting in possible injury
to persons in the vicinity.
• After operation, always switch off the tool and wait
until the diamond wheels come to a complete stop
before putting the tool down.
• Hold the tool firmly with one hand on the switch
handle and the other hand on the front grip when
performing the tool.
015076
Hold the tool firmly with both hands. First keep the
diamond wheels without making any contact with a
workpiece. Then turn the tool on and wait until the
diamond wheels attain full speed.
1
015044
To cut a workpiece, pull the tool toward you (not by
pushing away from you). Align the notch on the base
with your cutting line. Push down the front handle gently
until it stops and then pull the tool slowly.
Before finishing cutting operation and raising the tool,
switch it off first. Wait until the diamond wheels stop
completely and then raise the tool.
Remove the remaining portion between the two blade
passages by other appropriate tools.
MAINTENANCE
CAUTION:
• Always be sure that the tool is switched off and
unplugged before attempting to perform inspection
or maintenance.
• Never use gasoline, benzine, thinner, alcohol or the
like. Discoloration, deformation or cracks may result.
12
015045
The tool and its air vents have to be kept clean.
Regularly clean the tool's air vents or whenever the
vents start to become obstructed.
1. Inhalation vent
2. Exhaust vent
1. Notch
1. Hex wrench
2. Front handle
1. Dust nozzle
2. Vacuum cleaner
3. Hose

10
Dressing diamond wheel
If the cutting action of the diamond wheel begins to
diminish, use an old discarded coarse grit bench grinder
wheel or concrete block to dress the diamond wheel. To
do this, tightly secure the bench grinder wheel or
concrete block and cut in it.
To maintain product SAFETY and RELIABILITY, repairs,
carbon brush inspection and replacement, any other
maintenance or adjustment should be performed by
Makita Authorized Service Centers, always using Makita
replacement parts.
OPTIONAL ACCESSORIES
CAUTION:
• These accessories or attachments are
recommended for use with your Makita tool
specified in this manual. The use of any other
accessories or attachments might present a risk of
injury to persons. Only use accessory or
attachment for its stated purpose.
If you need any assistance for more details regarding
these accessories, ask your local Makita Service Center.
• Diamond wheels
NOTE:
• Some items in the list may be included in the tool
package as standard accessories. They may differ
from country to country.

11

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www.makita.com
Makita Jan-BaptistVinkstraat2, 3070, Belgium
Makita Corporation Anjo, Aichi, Japan
885366-223