Practical Grinder Application; Maintenance And Inspection - Hitachi G 12SE2 Handling

English
6. Conducting a trial run
Ensure that the abrasive products is correctly
mounted and tightened before use and run the tool
at no-load for 30 seconds in a safe position, stop
immediately if there is considerable vibration or if
other defects are detected.
If this condition occurs, check the machine to
determine the cause.
7. Confirm the push button
Confirm that the push button is disengaged by
pushing push button two or three times before
switching the power tool on (See Fig. 1).
8. Fixing the side handle
Screw the side handle into the gear cover.

PRACTICAL GRINDER APPLICATION

1. Pressure
To prolong the life of the machine and ensure a
first class finish, it is important that the machine
should not be overloaded by applying too much
pressure. In most applications, the weight of the
machine alone is sufficient for effective grinding.
Too much pressure will result in reduced rotational
speed, inferior surface finish, and overloading which
could reduce the life of the machine.
2. Grinding angle
Do not apply the entire surface of the depressed
center wheel to the material to be ground. As
shown in Fig. 3, the machine should be held at an
angle of 15° – 30° so that the external edge of the
depressed center wheel contacts the material at an
optimum angle.
3. To prevent a new depressed center wheel from
digging into the workpiece, initial grinding should
be performed by drawing the grinder across the
workpiece toward the operator (Fig. 3 direction B).
Once the leading edge of the depressed center
wheel is properly abraded, grinding may be
conducted in either direction.
4. Switch operation
[When the switch has locking mechanism]
Switch ON: To switch on, slide the lock lever in the
direction of A and press the paddle
lever in the direction of B as shown
in Fig. 4-a.
Furthermore, slide the lock lever in the
direction of C shown in Fig. 4-b while
pressing the paddle lever to lock and
enable continuous operation.
Switch OFF: To release the locking mode, press the
paddle lever in the direction of B shown
in Fig. 4-a, and release the paddle lever
to switch off.
[When the switch has no locking mechanism]
To switch on, slide the lock lever in the direction
of A and press the paddle lever in the direction
of B as shown in Fig. 4-a. Release the paddle lever
to switch off.
NOTE
The paddle lever can not be locked.
5. Precautions immediately after finishing operation
The wheel continues to rotate after the tool is
switched off.
After switching off the machine, do not put it down
until the depressed center wheel has come to a
5
complete stop. Apart from avoiding serious
accidents, this precaution will reduce the amount
of dust and swarf sucked into the machine.
CAUTIONS
Check that the work piece is properly supported.
Ensure that ventilation openings are kept clear when
working in dusty conditions.
If it should become necessary to clear dust, first
disconnect the tool from the mains supply (use non-
metallic objects) and avoid damaging internal parts.
Ensure that sparks resulting from use do not create
a hazard e.g. do not hit persons, or ignite flammable
substances.
Always use protective safety glasses and hearing
protectors, use other personal protective equipment
such as gloves, apron and helmet when necessary.
Always use eye and ear protection.
Other personal protective equipment such as dust
mask, gloves, helmet and apron should be worn
when necessary.
If in doubt, wear the protective equipment.
When the machine is not use, the power source
should be disconnected.
ASSEMBLING AND DISASSEMBLING THE
DEPRESSED CENTER WHEEL (Fig. 1)
CAUTION
Be sure to switch OFF and disconnect the attachment
plug from the receptacle to avoid a serious accident.
1. Assembling (Fig. 1)
(1) Turn the disc grinder upsidedown so that the spindle
is facing upward.
(2) Align the across flats of the wheel washer with the
notched part of the spindle, then attach them.
(3) Fit the protuberance of the depressed center wheel
onto the wheel washer.
(4) Screw the wheel nut onto the spindle.
(5) While pushing the push button with one hand, lock
the spindle by turning the depressed center wheel
slowly with the other hand.
Tighten the wheel nut by using the supplied wrench
as shown in Fig. 1.
2. Disassembling
Follow the above procedures in reverse.
CAUTIONS
Comfirm that the depressed center wheel is mounted
firmly.
Confirm that the push button is disengaged by
pushing push button two or three times before
switching the power tool on.

MAINTENANCE AND INSPECTION

1. Inspecting the depressed center wheel
Ensure that the depressed center wheel is free of
cracks and surface defects.
2. Inspecting the mounting screws
Regularly inspect all mounting screws and ensure
that they are properly tightened. Should any of the
screws be loose, retighten them immediately. Failure
to do so could result in serious hazard.
3. Inspecting the carbon brushes (Fig. 5)
The Motor employs carbon brushes which are
consumable parts. When they become worn to or
near the "wear limit", it could result in motor