User Manual

18 ENGLISH
Hammer drilling operation
CAUTION: There is tremendous and sudden
twisting force exerted on the tool/drill bit at the time of
hole break-through, when the hole becomes clogged
with chips and particles, or when striking reinforcing
rods embedded in the concrete. Always use the side
grip (auxiliary handle) and rmly hold the tool by
both side grip and switch handle during opera-
tions. Failure to do so may result in the loss of control
of the tool and potentially severe injury.
Set the action mode changing knob to the symbol.
Position the drill bit at the desired location for the hole,
then pull the switch trigger. Do not force the tool. Light
pressure gives best results. Keep the tool in position
and prevent it from slipping away from the hole.
Do not apply more pressure when the hole becomes
clogged with chips or particles. Instead, run the tool at
an idle, then remove the drill bit partially from the hole.
By repeating this several times, the hole will be cleaned
out and normal drilling may be resumed.
NOTE: Eccentricity in the drill bit rotation may occur
while operating the tool with no load. The tool auto-
matically centers itself during operation. This does not
affect the drilling precision.
Chipping/Scaling/Demolition
Set the action mode changing knob to the symbol.
Hold the tool rmly with both hands. Turn the tool on
and apply slight pressure on the tool so that the tool will
not bounce around, uncontrolled.
Pressing very hard on the tool will not increase the
efciency.
► Fig.32
Drilling in wood or metal
CAUTION: Hold the tool rmly and exert care
when the drill bit begins to break through the
workpiece. There is a tremendous force exerted on
the tool/drill bit at the time of hole break through.
CAUTION: A stuck drill bit can be removed
simply by setting the reversing switch to reverse
rotation in order to back out. However, the tool
may back out abruptly if you do not hold it rmly.
CAUTION: Always secure workpieces in a
vise or similar hold-down device.
NOTICE: Never use “rotation with hammering”
when the drill chuck is installed on the tool. The
drill chuck may be damaged.
Also, the drill chuck will come off when reversing the
tool.
NOTICE: Pressing excessively on the tool will
not speed up the drilling. In fact, this excessive
pressure will only serve to damage the tip of your drill
bit, decrease the tool performance and shorten the
service life of the tool.
Set the action mode changing knob to the symbol.
For DHR280/DHR282
Optional accessory
Attach the chuck adapter to a keyless drill chuck to
which 1/2"-20 size screw can be installed, and then
install them to the tool. When installing it, refer to the
section “Installing or removing drill bit”.
► Fig.33: 1. Keyless drill chuck 2. Chuck adapter
For DHR281/DHR283
Use the quick change drill chuck as standard equip-
ment. When installing it, refer to "changing the quick
change chuck for SDS-plus".
Hold the ring and turn the sleeve counterclockwise to
open the chuck jaws. Place the bit in the chuck as far as
it will go. Hold the ring rmly and turn the sleeve clock-
wise to tighten the chuck.
► Fig.34: 1. Sleeve 2. Ring
To remove the bit, hold the ring and turn the sleeve
counterclockwise.
Diamond core drilling
NOTICE: If performing diamond core drilling
operations using “rotation with hammering”
action, the diamond core bit may be damaged.
When performing diamond core drilling operations,
always set the change lever to the position to use
"rotation only" action.
Beating dust on the lter
Optional accessory
CAUTION: Do not turn the dial on the dust
case while the dust case is removed from the
dust collection system. Doing so may cause dust
inhalation.
CAUTION: Always switch off the tool when
turning the dial on the dust case. Turning the dial
while the tool is running may result in the loss of
control of the tool.
By beating the dust on the lter inside the dust case,
you can keep the vacuum efciency and also reduce
the number of times to dispose of the dust.
Turn the dial on the dust case three times after col-
lecting every 50,000 mm
3
of dust or when you feel the
vacuum performance declined.
NOTE: 50,000 mm
3
of dust equivalents to drilling 10
holes of ø10 mm and 65 mm depth (14 holes of ø3/8″
and 2″ depth).
► Fig.35: 1. Dust case 2. Dial