Cutting Procedures; Mounting And Dismounting The Saw Blade; Maintenance And Inspection - Hitachi C 7ST Handling Instructions Manual

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CAUTION
It is very hazardous to allow this lever (A) to remain
loosened. Always thoroughly clamp it.
3. Regulating the guide
The cutting position can be regulated by moving the
guide to the left or right after loosening its wing bolt.
The guide can be mounted on either the left or the
right side (Fig. 4).

CUTTING PROCEDURES

1. Place the saw body (base) on the lumber, and align
the intended line of cut with the saw blade, using
the notch at the front of the base. This relationship
of base to lumber should remain unchanged
regardless of the inclination of the base (Fig. 5).
2. Turn ON the switch before the saw blade contacts the
lumber. The switch is turned ON when the trigger is
squeezed, and turned OFF when the trigger is released.
3. Moving the saw straight at a constant speed will
produce optimum cutting.
CAUTIONS
Prior to cutting operation, make sure the material you
are going to cut. If the material to be cut is expected to
generate harmful / toxic dusts, make sure the dust bag or
appropriate dust extraction system is connected with
dust outlet tightly.
Wear the dust mask additionally, if available.
Before starting to saw, confirm that the saw blade
has attained full-speed revolution.
Should the saw blade stop or make an abnormal
noise while operating, promptly turn OFF the switch.
Always take care in preventing the power cord from
coming near to the revolving saw blade.
Using the circular saw with the saw blade facing
upwards or sideways is very hazardous. Such
uncommon applications should be avoided.
When cutting materials, always wear protective glasses.
When finished with a job, pull out the plug from
the receptacle.
MOUNTING AND DISMOUNTING THE SAW
BLADE
CAUTION
To avoid serious accident, ensure the switch is in the
OFF position, and the power source is disconnected.
1. Dismounting the saw blade
(1) Set the cutting volume at maximum, and place the
Circular Saw as shown in Fig. 6.
(2) Depress the lock lever, lock the spindle, and remove
the hexagonal-flange bolt with the box wrench.
(3) While holding the lower guard lever to keep the
lower guard fully retracted into the saw cover,
remove the saw blade.
2. Mounting the Saw Blade
(1) Thoroughly remove any sawdust which has accu-
mulated on the spindle, bolt and washers.
(2) As shown in Fig. 7, the side of Washer (A) with
a projected center the same diameter as the inner
diameter of the saw blade and the concave side
of Washer (B) must be fitted to the saw blade sides.
* Washer (A) is supplied for 3 types of saw blades
with the hole diameters of 16 mm, 20 mm and
30 mm. (When buying the Circular Saw, one
type of washer (A) is supplied.)
9
In case the hole diameter of your saw blade does
not correspond to that of washer (A), please contact
the shop where you purchased the Circular Saw.
(3) To assure proper rotation direction of the saw blade,
the arrow direction on the saw blade must coincide
with the arrow direction on the saw cover.
(4) Using the fingers, tighten the hexagonal-flange bolt
retaining the saw blade as much as possible. Then
depress the lock lever, lock the spindle, and thor-
oughly tighten the bolt.
CAUTION
After having attached the saw blade, reconfirm that the
lock lever is firmly secured in the prescribed position.

MAINTENANCE AND INSPECTION

1. Inspecting the saw blade
Since use of a dull saw blade will degrade efficiency
and cause possible motor malfunction, sharpen or
replace the saw blade as soon as abrasion is noted.
2. 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.
3. 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
brushes with new ones having the same carbon
brush No. shown in the figure when it becomes
worn to or near the "wear limit". In addition, always
keep carbon brushes clean and ensue that they
slide freely within the brush holders.
4. Replacing carbon brushes (Fig. 9)
Disassemble the brush caps with a slotted-head
screwdriver. The carbon brushes can then be easily
removed.
5. 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.
6. Adjusting the base and saw blade to maintain
perpendicularity
The angle between the base and the saw blade has
been adjusted to 90°, however should this
perpendicularity be lost for some reason, adjust in
the following manner:
(1) Turn the base face up (Fig. 10) and loosen the wing
bolt (A).
(2) Apply a square to the base and the saw blade and
turning the screw with a screwdriver, shift the
position of the base to produce the desired right
angle.(Fig. 11)
7. Maintenance of the lower guard
For safe and proper working, always keep the
machine and ventilation slots clean. The lower guard
must always be able to more freely and retract
automatically. Therefore, always keep the area
around the lower guard clean. Remove dust and
chips by blowing out with compressed air or with
a brush.