How To Use The Core Bit; Grease Replacement - Hitachi DH 28PC Handling Instructions Manual

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CAUTION
Exercise care not to excessively prolong driving time,
otherwise, the screws may be damaged by excessive
force.
Apply the rotary hammer perpendicularly to the screw
head when driving the screw; otherwise, the screw
head or bit will be damaged, or driving force will not
be fully transferred to the screw.
Do not attempt to use the rotary hammer in the
rotation and hammering function with the chuck
adapter and bit attached.
5. When driving wood screws (Fig. 10)
(1) Selecting a suitable driver bit
Employ cross-recessed screws, if possible, since the
driver bit easily slips off the heads of slotted-head screws.
(2) Driving in wood screws
Prior to driving in wood screws, make pilot holes
suitable for them in the wooden board. Apply the bit
to the screw head grooves and gently drive the screws
into the holes.
After rotating the rotary hammer at low speed for a
while until the wood screw is partly driven into the
wood, squeeze the trigger more strongly to obtain
the optimum driving force.
CAUTION
Exercise care in preparing a pilot hole suitable for the
wood screw taking the hardness of the wood into
consideration. Should the hole be excessively small
or shallow, requiring much power to drive the screw
into it, the thread of the wood screw may sometimes
be damaged.
6. Hammering only
This rotary hammer can be set to hammering only
mode by pressing the push button and turning the
change lever to the
(1) Mount the bull point or cold chisel.
(2) Press the push button and set the change lever to
mark. (Fig. 12)
The rotation is released, turn the tool and adjust the
tool to desired position. (Fig. 13)
(3) Turn the change lever to
Then bull point or cold chisel is locked.
7. Using stopper (Fig. 14)
(1) Loosen the wing bolt, and insert the stopper into the
mounting hole on the side handle.
(2) Adjust the stopper position according to the depth of
the hole and thighten the wing bolt securely.
8. How to use the drill bit (taper shank) and the taper
shank adapter
(1) Mount the taper shank adapter to the rotary hammer
(Fig. 15).
(2) Mount the drill bit (taper shank) to the taper shank
adapter (Fig. 15).
(3) Turn the switch ON, and drill a hole in prescribed
depth.
(4) To remove the drill bit (taper shank), insert the cotter
into the slot of the taper shank adapter and strike the
head of the cotter with a hammer supporting on a
rests (Fig. 16).
9. Using the side handle
When you wish to change a position of the side
handle, turn grip of the side handle counterclockwise
to loosen it, and then fasten it firmly.
13
mark (Fig. 11).
mark. (Fig. 11)
CAUTION:
When boring a hole, there can be a case where the
machine attempts to rotate by the reaction at the
time of penetrating a concrete wall and/or when a tip
of the blade comes in contact with the rebar.
Firmly fasten the side handle and hold the machine
with both of your hands. Unless you hold it securely,
an accident can occur.

HOW TO USE THE CORE BIT

(FOR LIGHT LOAD)
When boring penerating large holes use the core bit (for
light loads). At that time use with the center pin and the
core bit shank provided as optional accessories.
1. Mounting
CAUTION
Be sure to turn power OFF and disconnect the plug
from the receptacle.
(1) Mount the core bit to the core bit shank. (Fig. 17).
Lubricate the thread of the core bit shank to facilitate
disassembly.
(2) Mount the core bit to the rotary hammer (Fig. 18).
(3) Insert the center pin into the guide plate until it stops.
(4) Engage the guide plate with the core bit, and turn the
guide plate to the left or the right so that it does not
fall even if it faced downward. (Fig. 19).
2. How to bore (Fig. 20)
(1) Connect the plug to the power source.
(2) A spring is installed in the center pin.
Push it lightly to the wall or the floor straight.
Connect the core bit tip flush to the surface and start
operating.
(3) When boring about 5 mm in depth the position of the
hole will be established. Bore after that removing the
center pin and the guide plate from core bit.
(4) Application of excessive force will not only expedite
the work, but will deteriorate the tip edge of the drill
bit, resulting in reduced service life of the rotary
hammer.
CAUTION
When removing the center pin and the guide plate,
turn OFF the switch and disconnect the plug from the
receptacle.
3. Dismounting (Fig. 21)
Remove the core bit shank from the rotary hammer
and strike the head of the core bit shank strongly two
or three times with a manual hammer holding the
core bit, then the thread becomes loose and the core
bit can be removed.

GREASE REPLACEMENT

This machine is full air-tight construction to protect
against dust incursion and to prevent lubricant leakage.
This machine can be used without grease replenishment
for an extended period of time. However, perform the
grease replacement to extend the service life. Replace
the grease as described below.
1. Grease Replacement Period
You should look at the grease when you change the
carbon brush. (See item 4 in the section
MAINTENANCE AND INSPECTION.)
Ask for grease replacement at the nearest authorized
Hitachi Service Center.