Hitachi G 12VA Instrucciones De Manejo página 9

After adjustment, if grinder operation is required,
perform the operation only after setting the lever
in closed position.
Lubricate the sliding section of the set piece (B) and
the lever if the lever does not move smoothly.
5. Ensure that mounted wheels and points are fitted
in accordance with the manufacturer's instructions.
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 on "ASSEMBLING
AND DISASSEMBLING ACCESSORIES".
Ensure that blotters are used when they are provided
with the bonded abrasive product and when they
are required.
Do not use separate reducing bushings or adaptors
to adapt large hole abrasive wheels.
For tools intended to be fitted with threaded hole
wheel, ensure that the thread in the wheel is long
enough to accept the spindle length.
Do not use cutting off wheel for side grinding.
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.
9. Adjusting the number of revolution (G12VA, G13VA,
G15VA)
Above models are equipped with an electronic
infinite-variable-speed drive and can change the
number of revolution according to a use.
If you turn and set the dial scale (Fig. 4) to 6, the
number of revolution increases, and if you turn and
set it to 1, the number of revolution decreases.
Before use, set the number of revolution using the
dial. In so doing, refer to the following table as
a rough guide.
Dial Use
1 Polishing, finishing
Removal of paint or
2
coat
3 Removal of rust
4 Removal of burrs
Grinding
5
Rough grinding
6 Cutting
NOTE: Use caution not to turn the dial scale to any value
below 1 or above 6.
Tools
Radial grinding disc
Sanding disc
Depressed center
wheel
Depressed center
wheel
Diamond wheel
10. Caution when using near welding equipment
When using the grinder in the immediate vicinity
of welding equipment, the rotational speed may
become unstable. Do not use the grinder near
welding equipment.
PRACTICAL GRINDER APPLICATION
1. Pressure
Do not apply the grinding wheel strongly to the
grinding surface. The grinder makes use of electronic
circuit, so during application of load rotates at high
speed, so ample grinding effect can be obtained by
applying light pressure. If a strong grinding pressure
or other abnormal load is applied, the overload
protection circuit will operate and make the grinder
stop rotating, so please stop applying load
immediately. Following this, switching the power
OFF and then ON again, will cause the rotation to
increase to the regular speed.
CAUTION: (G12VA, G13VA, G15VA)
When using the tool at any value except the full
speed (Dial scale 6), the motor cannot be sufficiently
cooled due to the decreased number of revolution.
This could result in the risk of burning and damaging
the motor before an overload protective mechanism
starts to function.
Make sure that you use the tool by lightly applying
it to the surface of material when you use it at any
value except the full speed (Dial scale 6).
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. 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
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.
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