Functional Description; Operation - Makita DA391D Instruction Manual

3. Charge the battery cartridge with room tempera-
ture at 10°C – 40°C (50°F – 104°F). Let a hot bat-
tery cartridge cool down before charging it.
4. Charge the Nickel Metal Hydride battery car-
tridge when you do not use it for more than six
months.

FUNCTIONAL DESCRIPTION

CAUTION:
• Always be sure that the tool is switched off and the bat-
tery cartridge is removed before adjusting or checking
function on the tool.
Installing or removing battery cartridge (Fig. 1)
• Always switch off the tool before insertion or removal of
the battery cartridge.
• To remove the battery cartridge, pull out the set plate
on the tool and grasp both sides of the cartridge while
withdrawing it from the tool.
• To insert the battery cartridge, align the tongue on the
battery cartridge with the groove in the housing and slip
it into place. Snap the set plate back into place. Be sure
to close the set plate fully before using the tool to pre-
vent the battery cartridge from accidentally falling out of
the tool.
• Do not use force when inserting the battery cartridge. If
the cartridge does not slide in easily, it is not being
inserted correctly.
Switch action (Fig. 2)
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 switch trigger. Tool speed
is increased by increasing pressure on the switch trigger.
Release the switch trigger to stop.
Reversing switch action (Fig. 3)
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 reversing switch lever is in the neutral position,
the switch trigger cannot be pulled.
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.
Overload protector (Fig. 4)
The overload protector automatically cuts out to break
the circuit and the button pops out, whenever heavy work
is prolonged. Wait 20 – 30 seconds before pressing the
reset button to resume operation. The tool should be
switched off when you press the reset button, however.
4
ASSEMBLY
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.
Installing or removing driver bit or drill bit (Fig. 5)
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 firmly and turn the sleeve clock-
wise to tighten the chuck.
To remove the bit, hold the ring and turn the sleeve coun-
terclockwise.

OPERATION

Screwdriving operation (Fig. 6)
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 trigger just as
the screw bottoms out. If the trigger is not released, the
screw may strip out the hole or the screw and/or bit may
be damaged.
CAUTION:
• Make sure that the driver bit is inserted straight in the
screw head, or the screw and/or bit may be damaged.
NOTE:
• 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
Drilling operation
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.
Recommended size of
pilot hole (mm)
2.0 – 2.2
2.2 – 2.5
2.5 – 2.8
2.9 – 3.2