Installing Dust Collection Hose; Maintenance And Inspection - Hitachi Koki CM 12Y Handling Instructions Manual

INSTALLING DUST COLLECTION HOSE

When cutting a material which generates cutting dust,
use the dust collection hose as follows:
(1) Remove the rubber cab and install the accessory
hose. (Fig. 1)
(2) Install the dust collector hose for the power tool
in the accessory hose. (Fig. 1)
CAUTION
Do not use the dust collection hose when cutting
metal.
Always install a rubber cap on the dust collection
adapter when the dust collection hose is not used.
INSTALLING/REMOVING DIAMOND WHEEL
1. Installation
(1) Wipe the cutting dust from the spindle and wash-
ers.
(2) Make sure the rotation direction of the diamond
wheel conforms to the direction indicated on the
wheel guard and install the diamond wheel as
shown in Fig. 2 and 3.
• Install the wheel washer (B) (silver) on the inner
side when the hole diameter of the diamond wheel
is 22.2 mm.
• Install the wheel washer (C) (black) on the inner
side when the hole diameter of the diamond wheel
is 20.0 mm.
(3) Press the lock pin and secure the spindle. Tighten
the bolt adequately with the provided wrench.
(Fig. 5 and 6)
NOTE
Always use the provided wrench to secure the bolt.
Be careful because the bolt tightens to the left
(counterclockwise direction) to prevent it from being
loosened during cutting. (Fig. 6)
2. Removal
Remove the bolt with the provided wrench and
remove the diamond wheel. (Fig. 6)
CUTTING
1. Wheel guard adjustment (Fig. 4)
Adjust the wheel guard angle with the knob so dust
and debris from the material or sparks do not
contact the operator during the cutting operation.
2. Cutting Procedures (Fig. 7)
(1) Place this tool on the material to be cut and align
the premarked line and the diamond wheel.
The cutting can be performed smoothly if you cut
straight ahead on the scribed line in the initial cut.
(2) Turn on the switch when the diamond wheel is not
touching the material to be cut.
CAUTION
Always check the diamond wheel before starting
work. Never use a diamond wheel which is cracked,
broken or bent.
Do not apply water or coolant to the diamond
wheel.
Start cutting only when diamond wheel reaches its
maximum speed.
If the diamond wheel seizes or there is any abnor-
mal noise, immediately turn the power off.
Never use the diamond wheel to cut zig zag 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.
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 efficiency. 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 boding agent and hasten the wear of the dia-
mond layer. On the other hand, materials which
produce powdery cutting particles may cause clog-
ging of the diamond layer which will reduce cutting
efficiency. When clogging occurs, additional force
applied in an attempt to increase cutting speed will
sometime cause sparks to appear around the cir-
cumference of the diamond wheel. In such a case,
stop using the cutter and carefully inspect the cutting
edge by rubbing it with your fingers. 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 effectiveness of the diamond
layer and will extend the service life of the diamond
wheel.
The diamond material is susceptible to high tem-
peratures and will begin to deteriorate at approxi-
mately 600°C. Higher temperatures will cause de-
composition 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. Fail-
ure 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
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 car-
bon brush can result in motor trouble, replace the
carbon brush with a new one having the same
carbon brush numbers shown in the figure 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.
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