Drilling Operation; Maintenance; Replacing Carbon Brushes - Makita BDF441 Betriebsanleitung

Insert the side grip so that the protrusions on the grip base
fit in between the grooves on the tool barrel. Then tighten
the grip by turning clockwise.
Installing or removing driver bit or drill bit
(Fig. 9)
Turn the sleeve counterclockwise to open the chuck jaws.
Place the bit in the chuck as far as it will go. Turn the
sleeve clockwise to tighten the chuck. To remove the bit,
turn the sleeve counterclockwise.
Installing bit holder (Fig. 10)
Fit the bit holder into the protrusion at the tool foot on
either right or left side and secure it with a screw.
When not using the driver bit, keep it in the bit holders.
Bits 45 mm long can be kept there.
Hook (Fig. 11)
The hook is convenient for temporarily hanging the tool.
This can be installed on either side of the tool.
To install the hook, insert it into a groove in the tool hous-
ing on either side and then secure it with a screw. To
remove, loosen the screw and then take it out.
OPERATION (Fig. 12)
Screwdriving operation
First, slide the action mode change lever to the position of
symbol and select the fastening torque.
Place the point of the driver bit in the screw head and
apply pressure to the tool. Start the tool slowly and then
increase the speed gradually. Release the switch trigger
as soon as the clutch cuts in.
NOTE:
• Make sure that the driver bit is inserted straight in the
screw head, or the screw and/or bit may be damaged.
• When driving wood screws, predrill pilot holes to make
driving easier and to prevent splitting of the workpiece.
See the chart.
Nominal diameter of wood
screw (mm)
3.1
3.5
3.8
4.5
4.8
5.1
5.5
5.8
6.1
• If the tool is operated continuously until the battery car-
tridge has discharged, allow the tool to rest for 15 min-
utes before proceeding with a fresh battery.
Recommended size of pilot
hole (mm)
2.0 - 2.2
2.2 - 2.5
2.5 - 2.8
2.9 - 3.2
3.1 - 3.4
3.3 - 3.6
3.7 - 3.9
4.0 - 4.2
4.2 - 4.4

Drilling operation

First, slide the action mode change lever to the position of
symbol.
Drilling in wood
When drilling in wood, the best results are obtained with
wood drills equipped with a guide screw. The guide screw
makes drilling easier by pulling the bit into the workpiece.
Drilling in metal
To prevent the bit from slipping when starting a hole,
make an indentation with a center-punch and hammer at
the point to be drilled. Place the point of the bit in the
indentation and start drilling.
Use a cutting lubricant when drilling metals. The excep-
tions are iron and brass which should be drilled dry.
CAUTION:
• 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 bit, decrease the tool perfor-
mance and shorten the service life of the tool.
• There is a tremendous force exerted on the tool/bit at
the time of hole break through. Hold the tool firmly and
exert care when the bit begins to break through the
workpiece.
• A stuck 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 firmly.
• Always secure small workpieces in a vise or similar
hold-down device.
• If the tool is operated continuously until the battery car-
tridge has discharged, allow the tool to rest for 15 min-
utes before proceeding with a fresh battery.

MAINTENANCE

CAUTION:
• Always be sure that the tool is switched off and the bat-
tery cartridge is removed before attempting to perform
inspection or maintenance.

Replacing carbon brushes

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. (Fig. 13)
Use a screwdriver to remove two screws then remove the
rear cover. (Fig. 14)
Raise the arm part of the spring and then place it in the
recessed part of the housing with a slotted bit screwdriver
of slender shaft or the like. (Fig. 15)
Use pliers to remove the carbonbrush caps of the carbon
brushes. Take out the worn carbon brushes, insert the
new ones and replace the carbonbrush caps in reverse.
(Fig. 16)
Make sure that the carbonbrush caps have fit into the
holes in brush holders securely. (Fig. 17)
Reinstall the rear cover and tighten two screws securely.
9