Practical Grinder Applications - Hitachi PDA-100K Handling Instructions Manual

For details, refer to the item "Assembling and Dis as sem bling the depressed center wheel."
8. Apply a trial run
To start grinding work without checking for possible cracks and splits in the depressed
center wheel is very dangerous. Prior to start of grinding, direct the grinder in a direction
where no one is present, and apply a trial run without fail to confi rm that the grinder displays
no abnormalities.
Duration of the trial run is as follows:
When depressed center wheels is replaced ........ 3 minutes or more
When starting daily work ...................................... 1 minute or more

PRACTICAL GRINDER APPLICATIONS

1. Since grinding by utilizing only the grinder's own weight is feasible, the grinder should never
be pressed forcibly against the plane to be ground Hold the grinder lightly so that it only
slightly contacts the plane to be ground.
Heavy pressure will reduce the revolving speed and such deteriorate the fi nished surface,
and phe nom e na as overload will lead to burning out of the motor.
2. Do not utilize the grinder entire surface when
grinding. Use only its peripheral surface by tilting
the wheel at an angle of 15 – 30°, as shown in
Fig. 1.
3. When a grinder equipped with a new depressed
center wheel is pushed forward (direction A), the
wheel edge may occasionally cut into the material
to be ground. Always pull it backward (direction
B) in this instance.
However, once the depressed center wheel angle has been adequately abraded, both
forward and backward operations are permissible.
4. The provided depressed center wheel (resinoid wheel) is rated as Class A grain and #36
grain size.
Accordingly, its range of applications cover a wide variety, proving to be most suitable
for heavy grinding of general steel materials. Since the wheel grain size is rather coarse,
creating a fi ne-surfaced fi nish is very diffi cult.
In this instance, hold the grinder lightly as through trying to lift it, and apply grinding slowly
at a constant low speed. Whereby a fi ne fi nish similar to that accomplished with a fi ne-grain
depressed center wheel is obtainable.
5. Switching on the grinder
The switch can be turned ON by turning its lever ON side, or turn OFF by turning its lever to
the OFF side.
6. Precaution after use
Do not lay the grinder down immediately after use in a place where there are many
shavings and much dirt and dust until it has completely stopped revolving.
CAUTION
Shock to the main body can be the cause of cracks or splits in the depressed
○
center wheel. Be es pe cial ly careful to avoid sudden shocks when using the
equipment.
A
25
English
15° – 30°
B
Fig. 1