Bosch 1004VSR - Manual (Page 8)

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You will extend the life of your bits and do
neater work if you always put the bit in contact
with the work before pulling the trigger. During
the operation, hold the tool firmly and exert
light, steady pressure. Too much pressure at
low speed will stall the tool. Too little pressure
will keep the bit from cutting and cause excess
friction by sliding over the surface. This can be
damaging to both tool and bit.
DRILLING WITH VARIABLE SPEED
The trigger controlled variable speed feature
will eliminate the need for center punches in
hard materials. The variable speed trigger
allows you to slowly increase RPM. By using a
slow starting speed, you are able to keep the
bit from “wandering”. You can increase the
speed as the bit “bites” into the work by
squeezing the trigger.
DRIVING WITH VARIABLE SPEED
Variable speed drills will double as a power
screwdriver by using a screwdriver bit in the
drill mode. The technique is to start slowly,
increasing the speed as the screw runs down.
Set the screw snugly by slowing to a stop. Prior
to driving screws, pilot and clearance holes
should be drilled.
FASTENING WITH SCREWS
The procedure shown in (Fig. 4) will enable
you to fasten materials together with your
hammer drill in the drill mode without
stripping, splitting or separating the material.
First, clamp the pieces together and drill the
first hole 2/3 the diameter of the screw. If the
material is soft, drill only 2/3 the proper
length. If it is hard, drill the entire length.
Second, unclamp the pieces and drill the
second hole the same diameter as the screw
shank in the first or top piece of wood.
Third, if flat head screw is used, countersink
the hole to make the screw flush with the
surface. Then, simply apply even pressure
when driving the screw. The screw shank
clearance hole in the first piece allows the
screw head to pull the pieces tightly together.
The adjustable screw drill accessory will do
all of these operations quickly and easily.
Screw drills are available for screw sizes No.
6, 8, 10 and 12.
Operating Tips
DRILL BITS
Always inspect drill bits for excessive wear.
Use only bits that are sharp and in good
condition.
TWIST BITS: Available with straight and
reduced shanks for wood and light duty metal
drilling. High speed bits cut faster and last
longer on hard materials.
CARBIDE TIPPED BITS: Used for drilling
stone, concrete, plaster, cement and other
unusually hard nonmetals. Use continuous
heavy feed pressure when employing carbide
tip bits.
DRILLING WOOD
Be certain workpiece is clamped or anchored
firmly. Always apply pressure in a straight line
with the drill bit. Maintain enough pressure to
keep the drill “biting”.
When drilling holes in wood, twist bits can be
used. Twist bits may overheat unless pulled out
frequently to clear chips from flutes.
Use a “back-up” block of wood for work that is
likely to splinter, such as thin materials.
You will drill a cleaner hole if you ease up on
the pressure just before the bit breaks through
2. Drill same
diameter as
screw shank.
3. Countersink
same diameter
as screw head.
1. Drill 2/3 diameter and
2/3 of screw length for
soft materials, full
length for hard
materials.
Adjustable
Screw
Drill
Screw
Apply a slight
even pressure
when driving
screws.
FASTENING
WITH SCREWS
FIG. 4