Maintenance And Inspection - Hitachi CM 12Y Operating Instructions Manual

English
○ Do not apply water or coolant to the diamond wheel.
○ Start cutting only when diamond wheel reaches its
maximum speed.
○ Switching the tool on and off repeatedly within a short
time may cause burn damage of the motor.
○ If the diamond wheel seizes or there is any abnormal
noise, immediately turn the power off .
○ Never use the diamond wheel to cut zigzag or curved
lines. Never use the side surface of the diamond wheel.
Never use to perform inclination cutting.
○ If excessive force is applied to the diamond wheel to
make it align with the premarked line during cutting,
this might not only overload the motor and cause burn
damage but may also overheat the diamond wheel and
shorten the service life.
○ Secure the workpiece. A workpiece clamped with
clamping devices or in a vice is held more securely than
by hand.
○ Take care not to allow the power cord to come into
contact with the diamond wheel during operation.
○ When the work is completed, turn the power off and
disconnect the power plug from the receptacle.

MAINTENANCE AND INSPECTION

1. Inspection the diamond wheel
A worn diamond wheel overloads the motor and
reduces working effi ciency. Replace with a new one.
2. Diamond wheel clogging
The rate of wear of the diamond layer cutting edge will vary
depending on the type of material being cut, the cutting
speed, etc. In general, materials which produce granular
cutting particles may scrape the bodying agent and hasten
the wear of the diamond layer. On the other hand, materials
which produce powdery cutting particles may cause
clogging of the diamond layer which will reduce cutting
effi ciency. When clogging occurs, additional force applied
in an attempt to increase cutting speed will sometime
cause sparks to appear around the circumference of the
diamond wheel. In such a case, stop using the cutter and
carefully inspect the cutting edge by rubbing it with your
fi ngers. If the diamond layer feels smooth (no roughness
or abrasiveness), it is clogged with dust and must be
"dressed".
For thorough dressing, approximately 5 meters of
slightly accelerated cutting at a depth of 10mm in a
relative soft material which produces granular cutting
particles (such as a cement block or brick) will restore
the cutting eff ectiveness of the diamond layer and will
extend the service life of the diamond wheel.
The diamond material is susceptible to high temperatures
and will begin to deteriorate at approximately 600°C.
Higher temperatures will cause decomposition of the
diamond material. Accordingly, it is important to perform
"dressing" as soon as clogging or sparking occurs.
3. 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.
4. Maintenance of the motor
The motor unit winding is the very "heart" of the power
tool.
Exercise due care to ensure the winding does not
8
become damaged and/or wet with oil or water.
5. Inspecting the carbon brushes (Fig. 8)
The motor employs carbon brushes which are consumable
parts. Since an excessively worn carbon brush can result
in motor trouble, replace the carbon brush with a new one
having the same carbon brush numbers shown in the
fi gure when it becomes worn to or near the "wear limit". In
addition, always keep carbon brushes clean and ensure
that they slide freely within the brush holders.
6. Replacing a carbon brush
Disassemble the brush cap with a minus-head
screwdriver. The carbon brush can then be easily
removed.
7. Service parts list
A: Item No.
B: Code No.
C: No. Used
D: Remarks
CAUTION
Repair, modifi cation and inspection of Hitachi Power
Tools must be carried out by a Hitachi Authorized
Service Center.
This Parts List will be helpful if presented with the tool to
the Hitachi Authorized Service Center when requesting
repair or other maintenance.
In the operation and maintenance of power tools, the
safety regulations and standards prescribed in each
country must be observed.
MODIFICATIONS
Hitachi Power Tools are constantly being improved
and modifi ed to incorporate the latest technological
advancements.
Accordingly, some parts (i.e. code numbers and/or
design) may be changed without prior notice.
GUARANTEE
We guarantee Hitachi Power Tools in accordance with
statutory/country specifi c regulation. This guarantee does
not cover defects or damage due to misuse, abuse, or
normal wear and tear. In case of complaint, please send
the Power Tool, undismantled, with the GUARANTEE
CERTIFICATE found at the end of this Handling instruction,
to a Hitachi Authorized Service Center.
NOTE
Due to HITACHI's continuing program of research and
development, the specifi cations herein are subject to
change without prior notice.