Grinder Operation - Hitachi G12SQ Safety Instructions And Instruction Manual

9. Use only properly rated depressed center wheels.
Use only depressed center wheels rated at
13,300/min for G12SQ, 12,000/min for G13SQ or
more.
Using a depressed center wheel rated less can lead
to wheel disintegration during operation and cause
serious bodily injury.
10. Check the push button.
Make sure that the push button is disengaged by
pushing push button two or three times before
turning on the grinder. (Fig. 5)

GRINDER OPERATION

1. Hold the grinder firmly by its housing and side
handle (Fig. 1).
The grinder produces a counterforce which must
be controlled by firmly holding onto the grinder.
2. Switch operation
[When the switch has locking mechanism]
Switch ON : To switch on, slide the off lock lever
in the direction of A and press the
switch lever in the direction of B as
shown in Fig. 3-a. Furthermore, push
the on lock button in the direction of
C shown in Fig. 3-b while pressing
the switch lever to lock and enable
continuous operation.
Switch OFF : To release the locking mode, press
the switch lever in the direction of B
shown in Fig. 3-a, and release the
switch lever to switch off.
[When the switch has no locking mechanism]
To switch on, slide the off lock lever in the direction
of A and press the switch lever in the direction of
B as shown in Fig. 3-a.
Release the switch lever to switch off.
a
( )
Toil cover
Switch lever
Off lock leve
3. Use light grinding pressure.
There is no need to press hard when grinding.
Usually the grinder's own weight is sufficient to
allow the required light contact with the surface to
be ground.
b
( )
On lock button
Fig. 3
WARNING:
Do not press the grinder forcibly against the
surface to be ground. Heavy pressure can result
in wheel breakage and serious injury. It can also
damage the surface being ground or damage the
grinder's motor.
4. Use proper grinding angle.
Grind only with the wheel's edge by lifting the
grinder 15° to 30°, as shown in Fig. 4.
CAUTION:
Do not use the entire surface of the depressed
center wheel. Use only the edge of the depressed
center wheel.
5. Move the grinder in the proper direction.
When using a new depressed center wheel in
direction A (Fig. 4), the wheel edge may cut into the
workpiece. In this case, grind in direction B (Fig. 4).
Once the wheel edge is worn, the workpiece can be
ground in both directions.
A
NOTE:
The wheel provided (resinoid wheel) is rated as
Class A grain and # 36 grain size. It is most suitable
for heavy grinding of steel and other types of
materials.
6. Adjust operation to desired finish.
For a fine finish, decrease pressure by lifting
slightly. Grind slowly and at the appropriate speed.
Push
CAUTION:
The revolving depressed center wheel will create
air turbulence.
Do no lay the grinder down in areas of dust or dirt
until it has come to a complete stop.
English
15° – 30°
B
Fig. 4
11