Maintenance - Makita 6914D Instruction Manual

OPERATION
Machine screw
.
N m
M8
20
15
M6
10
5
0
0.5 1.0
Standard bolt
.
N m
80
60
40
20
1.0 2.0
High tensile bolt
80
.
N m
60
40
20
1.0 2.0

MAINTENANCE

1. Limit mark
The proper fastening torque may differ depending upon the kind or size of the
004525
screw/bolt, the material of the workpiece to be fastened, etc. The relation
between fastening torque and fastening time is shown in the figures.
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
M8
screw and turn the tool on to start operation.
NOTE:
M6
• Use the proper bit for the head of the screw/bolt that you wish to use.
(S)
• When fastening screw M8 or smaller, carefully adjust pressure on the
switch trigger so that the screw is not damaged.
004526
• 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,
M12
damaged, etc. Before starting your job, always perform a test operation
M10
to determine the proper fastening time for your screw.
M12
• If the tool is operated continuously until the battery cartridge has
M8
M10
discharged, allow the tool to rest for 15 minutes before proceeding with a
M8
fresh battery.
The fastening torque is affected by a wide variety of factors including the fol-
3.0 (S)
lowing. After fastening, always check the torque with a torque wrench.
1. When the battery cartridge is discharged almost completely, voltage will
004921
drop and the fastening torque will be reduced.
2. Driver bit or socket bit
M10
Failure to use the correct size driver bit or socket bit will cause a reduc-
M10
tion in the fastening torque.
M8
3. Bolt
M8
•
3.0 (S)
•
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 reduction in the fastening
torque.
CAUTION:
• Always be sure that the tool is switched off and the battery cartridge is
removed before attempting to perform inspection or maintenance.
Replacing carbon brushes
001145
Remove and check the carbon brushes regularly. Replace when they wear
down to the limit mark. Keep the carbon brushes clean and free to slip in the
holders. Both carbon brushes should be replaced at the same time. Use only
identical carbon brushes.
1
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.
7