DeWalt DC740 Instruction Manual page 11

a hex key (not supplied) of 1/4" or greater size. Using a wooden
mallet or similar object, strike the longer end in the clockwise
direction, as shown. This will loosen the screw inside the chuck.
Open chuck jaws fully, insert screwdriver (or Torx tool if required)
into front of chuck between jaws to engage screw head. Remove
screw by turning clockwise (left-hand-thread). Place hex key in
chuck and tighten, as shown in Fig. 8. Using a wooden mallet or
similar object, strike key sharply in the counterclockwise direction.
This will loosen the chuck so that it can be unscrewed by hand.
FIG. 7
Chuck Installation (Fig. 8)
Screw the chuck on by hand as far as it will go and insert
screw (LH thread). Tighten screw securely. Tighten the chuck
around the shorter end of a 1/4" or larger hex key (not supplied)
strike the longer end in the clockwise direction with a wooden
mallet, as shown. Tighten the screw once again by turning in a
counterclockwise direction.
Operation as a Drill
Turn the collar to the drill bit symbol. Install and tighten the desired
drill bit in the chuck. Select the desired speed/torque range using the
dual range gear shifter to match the speed and torque to the planned
operation. Follow these instructions for best results when drilling.
DRILLING
1. Use sharp drill bits only. For WOOD, use twist drill bits, spade
bits, power auger bits, or hole saws. For METAL, use high
speed steel twist drill bits or hole saws.
2. Be sure the material to be drilled is anchored or clamped
firmly. If drilling thin material, use a "back-up" block to prevent
damage to the material.
3. Always apply pressure in a straight line with the bit. Use enough
pressure to keep the drill bit biting, but do not push hard enough
to stall the motor or deflect the bit.
4. Hold tool firmly to control the twisting action of the drill.
5. IF DRILL STALLS, it is usually because it is being overloaded.
RELEASE TRIGGER IMMEDIATELY, remove drill bit from work,
and determine cause of stalling. DO NOT CLICK TRIGGER
OFF AND ON IN AN ATTEMPT TO START A STALLED DRILL
– THIS CAN DAMAGE THE DRILL.
6. To minimize stalling or breaking through the material, reduce
pressure on drill and ease the bit through the last fractional part
of the hole.
FIG. 8
7. Keep the motor running when pulling the bit back out of a drilled
hole. This will help prevent jamming.
8. With variable speed drills there is no need to center punch
the point to be drilled. Use a slow speed to start the hole and
accelerate by squeezing the trigger harder when the hole is
deep enough to drill without the bit skipping out. Operate at full
on after starting the bit.
Drilling in Wood
Holes in wood can be made with the same twist drills used for metal.
These bits may overheat unless pulled out frequently to clear chips
from the flutes. For larger holes, use low speed wood bits. Work that
is likely to splinter should be backed up with a block of wood.
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