Prior To Operation; Practical Grinder Application - Hitachi G 12SC2 Handling Instructions Manual

PRIOR TO OPERATION

1. Power source
Ensure that the power source to be utilized conforms
to the power requirements specifi ed on the product
nameplate.
2. Power switch
Ensure that the power switch is in the OFF position. If
the plug is connected to a receptacle while the power
switch is in the ON position, the power tool will start
operating immediately, which could cause a serious
accident.
3. Extension cord
When the work area is removed from the power source,
use an extension cord of suffi cient thickness and rated
capacity. The extension cord should be kept as short as
practicable.
4. Confi rming condition of the environment
Confi rm that the work site is placed under appropriate
conditions conforming to prescribed precautions.
When grinding a thin steel plate, depending upon the
state of the workbench, a loud noise will be created due
to resounding noise from the steel plate being ground. To
eliminate unwanted noise in this instance, place a rubber
mat beneath the material to be ground.
5. Fitting and adjusting the wheel guard
The wheel guard is a protective device to prevent injury
should the depressed center wheel be shattered during
operation. Ensure that the wheel guard is properly fi tted
and fastened before commencing grinding operation.
By slightly loosening the setting screw, the wheel guard
can be turned and set at any desired angle for maximum
operational eff ectiveness. Ensure that the setting screw
is thoroughly tightened after adjusting the wheel guard.
6. Ensure that the depressed center wheel to be utilized is
the correct type and free of cracks or surface defects.
Also ensure that the depressed center wheel is properly
mounted and the wheel nut is securely tightened.
Refer to the section
DISASSEMBLING THE
WHEEL".
7. Conducting a trial run
Before commencing grinding operation, the grinder
should be given a trial run in a safe area to ensure that
it is properly assembled and that the depressed center
wheel is free from obvious defects.
Recommended trial run durations are as follows:
After replacing depressed center wheel
............................................... 3 minutes or more
Prior to starting routine work
............................................... 1 minutes or more
8. Confi rm the spindle lock mechanism
Confi rm that the spindle lock is disengaged by pushing
push button two or three times before switching the
power tool on (See Fig. 1).
9. Fixing the side handle
Screw the side handle into the gear cover.
10. RCD
The use of a residual current device with a rated residual
current of 30mA or less at all times is recommended.
on "ASSEMBLING AND
DEPRESSED CENTER

PRACTICAL GRINDER APPLICATION

1. Pressure
To prolong the life of the grinder and ensure a fi rst
class fi nish, it is important that the grinder should not
be overloaded by applying too much pressure. In most
applications, the weight of the grinder alone is suffi cient
for eff ective grinding. Too much pressure will rest in
reduced rotational speed, inferior surface fi nish, and
overloading which could reduce the life of the grinder.
2. Grinding angle
Do not apply the entire surface of the depressed center
wheel to the material to be ground. As shown in Fig. 2,
the grinder 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. 2 direction B). Once the leading edge of
the depressed center wheel is properly abraded, grinding
may be conducted in the either direction.
4. Switch operation
This enables the grinder always to be controlled with the
hand gripping the machine for maximum safety during
grinding operations.
<Intermittent use>
Switch ON: Press the switch lever.
Switch OFF: Release the Switch lever.
*<Continuous use>
Switch ON: Press the Switch lever. The switch lever is
locked by pull the locking button.
Switch OFF: Press and release the switch lever.
(*Subject to change depending on area)
5. Precautions Immediately after fi nishing operation
After switching off the grinder, do not put it down until the
depressed center wheel has come to a complete stop.
Apart from avoiding serious accidents, this precaution
will reduce the amount of dust and swarf sucked into the
grinder.
CAUTION
When the grinder is not in use, the power source should
be disconnected.
ASSEMBLING AND DISASSEMBLING THE
DEPRESSED CENTER WHEEL (Fig. 1)
CAUTION Be sure to switch power OFF and disconnect the
plug from the receptacle to avoid serious trouble.
1. Assembling (Fig. 1)
(1) Turn the grinder upside down so that the spindle is facing
upward.
(2) Mount the wheel washer onto the spindle.
(3) Fit the protuberance of the depressed center wheel or
diamond wheel onto the wheel washer.
(4) Assemble the wheel nut onto the spindle.
(For diamond wheel assembling, use the wheel nut with
the convex side against the diamond wheel.)
(5) Insert the push button to prevent rotation of the spindle,
and tighten the wheel nut with the accessory wrench, as
shown in Fig.1.
2. Disassembling
Follow the above procedures in reverse.
CAUTION
○ Confi rm that the depressed center wheel is mounted
fi rmly.
○ Confi rm that the spindle lock mechanism is disengaged
by pushing push button two or three times before
switching the grinder on.
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