7
Selecting the action mode (Fig. 8)
This tool is equipped with an action mode change lever.
For “rotation only”, turn the change lever to the
S
position. For “rotation with hammering”, turn the change
lever to the
t position.
CAUTION:
Always set the action mode change lever carefully into
the correct position. If you operate the tool with the
action mode change lever positioned half-way between
the
S position and the t position, tool damage may
result.
Diamond core drilling
CAUTION:
• When performing diamond core drilling operations,
always set the change lever to the
S position to use
“rotation only” action. If performing diamond core drill-
ing operations using “rotation with hammering” action,
the diamond core bit may be damaged.
• The drilling efficiency and service life of the diamond
core bit varies greatly depending on the kind or condi-
tion of the material to be drilled. In general, hard mate-
rial may dull the bit soon and soft materials such as
“green” concrete or concrete blocks may shorten the
service life of the bit.
• If the drilling action of the diamond core bit begins to
diminish, dress the bit using an old discarded coarse-
grit bench grinder wheel or concrete block. Tightly
secure the bench grinder wheel or concrete block and
drill in it. Continued use of dull bits may cause the dia-
mond chips to break or fall off.
• When using a wet type of diamond core bit, always
install a cover (optional accessory) on the tool to thor-
oughly protect the tool from water. Refer to the previ-
ously covered “Installing cover”.
• After using a wet type of diamond core bit, wash it in
water and store with the sponge and guide ring in a dry
location.
1. Drilling with wet type of diamond core bit
First, unplug the tool. Soak the sponge in water.
Place the tool with the bit end pointing upwards.
Carefully fill the bit about half full of water. Insert the
sponge into the bit gently with the side with the rivet
facing upwards as far as it will go. (Fig. 9)
CAUTION:
When filling the bit with water, be especially careful
not to let the tool get wet.
Remove water and dirt form the guide ring and from
the drilling location. Attach the adhesive sheet to
the drilling location and place the guide ring on it.
(Fig. 10)
Place the bit in the guide ring and turn the tool on.
(Fig. 11)
After drilling a pilot groove, turn the tool off and then
remove the guide ring and adhesive sheet. (Fig. 12)
Place the bit into the pilot groove and turn the tool
on. Pivot the tool gently in the hole to be drilled
while tilting it at an angle of 2° – 3°. Gradually
decrease the angle of tilt as the hole becomes
deeper. Immediately before hole breakthrough, the
tool should be held straight in relation to the hole.
After completing the hole, turn the tool off. Wait until
the bit has come to a complete stop before with-
drawing the tool. (Fig. 13)
CAUTION:
Make sure that water is running constantly from the
hole during operation. If the water flow becomes
inadequate, withdraw the tool slightly and press it
again. Water should run freely. But if the problem
persists, unplug the tool and replenish the bit with
water immediately.
When resuming operation, do not turn the tool on
until the bit end reaches the deepest portion of the
hole.
Remove core material from the bit through the front
opening. (Fig. 14)
CAUTION:
When removing the core material from the bit, do not
gouge it out or hit the bit with a screwdriver, etc.
If you have difficulty removing the core material
through the front opening, use the hex wrench to
loosen the screws and remove the holder. Then
remove the sponge and core material through the
rear opening. (Fig. 15)
To install the holder, align the marking on the holder
with that on the bit and tighten the screws securely
with the hex wrench. (Fig. 16)
CAUTION:
Be careful not to damage the diamond core bit or the
O ring on the holder.
2. Drilling with dry type of diamond core bit
First, unplug the tool. Assemble the bit shank, core
bit and center bit. Install the bit assembly in the drill
chuck. (Fig. 17)
Align the center bit with the center of the hole to be
drilled. Turn the tool on and drill in the concrete until
the diamond portion of the core bit has drilled to a
depth of 3 – 5 mm. This forms a pilot groove for you
to follow when you continue drilling. (Fig. 18)
Remove the center bit from the core bit and place
the core bit back into the pilot groove. Drill the hole
while holding the tool squarely against the concrete.
Do not apply excessive pressure to the tool when
drilling. (Fig. 19)
Reduce your pressure on the tool if the core bit con-
tacts reinforcing bars or foreign matter in the con-
crete and when the core bit begins to break through
the concrete. (Fig. 20)
To remove the core material from the core bit, point
the core bit downwards. If the core material does
not fall out of the core bit smoothly, insert a small rod
into a hole in the rear side of the core bit to push the
core material out. (Fig. 21)
CAUTION:
When drilling in “green” concrete or when drilling
downwards, dust may not be extracted through the
hole smoothly. In this case, use a dust collector to
collect the dust easily.
