Maintenance - Makita 6990D Betriebsanleitung

• Do not use force when inserting the battery cartridge. If
the cartridge does not slide in easily, it is not being
inserted correctly.
Installing or removing bit
Important:
Always be sure that the tool is switched off and the bat-
tery cartridge is removed before installing or removing
the bit.
Use only the driver bit or socket bit shown in the figure
below.
Do not use any other driver bit or socket bit.
To install the bit, pull the sleeve in the direction of the
arrow and insert the bit into the sleeve as far as it will go.
Then release the sleeve to secure the bit. (Fig. 2)
To remove the bit, pull the sleeve in the direction of the
arrow and pull the bit out firmly.
NOTE:
If the bit is not inserted deep enough into the sleeve, the
sleeve will not return to its original position and the bit will
not be secured. In this case, try re-inserting the bit
according to the instructions above.
Switch action (Fig. 3)
CAUTION:
Before inserting the battery cartridge into the tool, always
check to see that the switch trigger actuates properly and
returns to the "OFF" position when released.
To start the tool, simply pull the trigger. Tool speed is
increased by increasing pressure on the trigger. Release
the trigger to stop.
Reversing switch action (Fig. 4)
CAUTION:
• Always check the direction of rotation before operation.
• Use the reversing switch only after the tool comes to a
complete stop. Changing the direction of rotation
before the tool stops may damage the tool.
• When not operating the tool, always set the reversing
switch lever to the neutral position.
This tool has a reversing switch to change the direction
of rotation. Depress the reversing switch lever from the A
side for clockwise rotation or from the B side for counter-
clockwise rotation. When the switch lever is in the neutral
position, the switch trigger cannot be pulled.
Operation (Fig. 5 & 6)
The proper fastening torque may differ depending upon
the kind or size of the screw/bolt, the material of the
workpiece to be fastened, etc. The relation between fas-
tening torque and fastening time is shown in Fig. 5 for
standard bolt or Fig. 6 for high tensile bolt.
Hold the tool firmly and place the point of the driver bit in
the screw head. Apply forward pressure to the tool to the
extent that the bit will not slip off the screw and turn the
tool on to start operation.
NOTE:
• When fastening screw M8 or smaller, carefully adjust
pressure on the switch trigger so that the screw is not
damaged.
• Hold the tool pointed straight at the screw.
• If you tighten the screw for a time longer than shown in
the figures, the screw or the point of the driver bit may
be overstressed, stripped, damaged, etc. Before start-
ing your job, always perform a test operation to deter-
mine the proper fastening time for your screw.
The fastening torque is affected by a wide variety of fac-
tors including the following.
After fastening, always check the torque with a torque
wrench.
1. When the battery cartridge is discharged almost
completely, voltage will drop and the fastening
torque will be reduced.
2. Driver bit or socket bit Failure to use the correct size
driver bit or socket bit will cause a reduction in the
fastening torque.
3. Bolt
• Even though the torque coefficient and the class of
bolt are the same, the proper fastening torque will
differ according to the diameter of bolt.
• Even though the diameters of bolts are the same,
the proper fastening torque will differ according to
the torque coefficient, the class of bolt and the bolt
length.
4. The manner of holding the tool or the material of
driving position to be fastened will affect the torque.
5. Operating the tool at low speed will cause a reduc-
tion in the fastening torque.

MAINTENANCE

CAUTION:
Always be sure that the tool is switched off and the bat-
tery cartridge is removed before carrying out any work on
the tool.
Replacement of carbon brushes (Fig. 7 & 8)
Replace carbon brushes when they are worn down to the
limit mark. Both identical carbon brushes should be
replaced at the same time.
To maintain product safety and reliability, repairs, mainte-
nance or adjustment should be carried out by a Makita
Authorized Service Center.
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