Maintenance; Replacing Carbon Brushes; Drilling Operation - Makita BDF441 Instruction Manual

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
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NOTE:
If the tool is operated continuously until the battery
•
cartridge has discharged, allow the tool to rest for
15 minutes before proceeding with a fresh battery.

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
exceptions 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 performance 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.
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
Always secure small workpieces in a vise or similar
•
hold-down device.
If the tool is operated continuously until the battery
•
cartridge has discharged, allow the tool to rest for
15 minutes before proceeding with a fresh battery.

MAINTENANCE

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

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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.
Use a screwdriver to remove two screws then remove
the rear cover.
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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.
1
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8
1. Limit mark
1
1. Rear cover
2. Screws
1
2
1. Arm
2. Spring
3. Recessed part
2 3