DeWalt DW501 Guide D'utilisation page 7

The gear train has been designed for shifting only when the unit is
off. It may be necessary however, to rotate the chuck slightly by hand
to align the gears while turning the shift knob. DO NOT ATTEMPT
TO CHANGE SPEEDS by turning the shift knob when the tool is
running. Doing so will damage the gear train.
Hammer/Drill Selector
To switch the tool from the drilling mode to the hammering mode (or
vice-versa) rotate the dial on the applicable symbol shown in Figure
4. For straight drilling, align the drill bit symbol toward the chuck. For
hammering, align the hammer symbol with the chuck, as shown in
the figure.NOTE: The selector must be in either drill, or hammer/drill
mode at all times. There are no operable positions between the two.
Chuck
To insert bit, open chuck jaws by turning collar with fingers and
insert shank of bit about 3/4" (19mm) into chuck. Tighten chuck collar
by hand. Place chuck key in each of the three holes and tighten in
clockwise direction. It's important to tighten chuck with all three
holes. To release bit , turn chuck key counterclockwise in just one
hole, then loosen the chuck by hand.
Operation
DRILLING
1. Always unplug the drill when attaching or changing bits or
accessories.
2. Use sharp drill bits only. For WOOD, use the low speed setting
and twist drill bits, spade bits, power auger bits, or hole saws.
For METAL, use the low speed setting and steel twist drill bits or
hole saws. For MASONRY, such as brick, cement, cinder block,
etc., use carbide-tipped bits rated for percussion drilling. Use
low speed for bits greater than 3/8".
3. Be sure the material to be drilled is anchored or clamped firmly.
If drilling thin material, use a wood "back-up" block to prevent
damage to the material.
4. Always apply pressure in a straight line with the bit. Use enough
pressure to keep drill biting, but do not push hard enough to stall
the motor or deflect the bit.
5. Hold tool firmly to control the twisting action of the drill.
6. IF DRILL STALLS, it is usually because it is being overloaded or
improperly used. 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.
7. To minimize stalling or breaking through the material, reduce
pressure on drill and ease the bit through the last fractional part
of the hole.
8. Keep the motor running when pulling the bit back out of a drilled
hole. This will help prevent jamming.
9. 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.
DRILLING IN METAL
USE ONLY in the "low speed" gear range. Start drilling with slow
speed and increase to full power while applying firm pressure on the
tool. A smooth even flow of metal chips indicates the proper drilling
rate. Use a cutting lubricant when drilling metals. The exceptions are
cast iron and brass which should be drilled dry. The cutting lubricants
that work best are sulphurized cutting oil or lard oil; bacon-grease will
also serve the purpose.
NOTE: Large (5/16" to 1/2") holes in steel can be made easier if a
pilot hole (5/32" to 3/16") is drilled first.
DRILLING IN WOOD
USE ONLY in the "low speed" gear range. Start drilling with slow
speed and increase to full power while applying firm pressure on
the tool. Holes in wood can be made with the same twist drills used
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