Makita 8406C Manuel D'instructions page 7

When using a Nimbus diamond core bit, refer to the table below.
Speed change lever
Speed adjusting dial
Workpiece
Nimbus diamond
Brick
core bit
NOTE:
When drilling into concrete or bricks, also refer to the table below.
Material
-1
min
CAUTION:
• If the tool is operated continuously at low speeds for a long time, the motor will get overloaded and heated up.
• Always keep the speed adjusting dial positioned within the range of numbers 1 through 6. Never turn it beyond the
numbers 1 through 6. Tool damage will result.
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
position. For "rotation with hammering", turn the change
t
lever to the 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
S
the position and the
result.
Diamond core drilling
CAUTION:
• When performing diamond core drilling operations,
always set the change lever to the
"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.
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.
Type of bit Bit diameter
20 mm
30 mm
65 mm
90 mm
152 mm
Hard Soft
Low High
t
position, tool damage may
S
position to use
Tightly
1 2 3
1. Drilling with wet type of diamond core bit
First, unplug the tool. Soak the sponge in water.
S
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°.
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)
4 5 6 1 2 3 4 5 6
Gradually
7