SPARKY HeavyDuty BU2250 Instrucciones De Uso página 10

ing/unscrewing bolts, nuts or screws into the
chuck 2. Set the operation mode selector switch
5 in its rightmost position or turn it until the drill
bit symbol is entirely exposed. Select the rota-
tion direction necessary (screwing/unscrewing)
by lever 9.
The rpm and the shut-off torque can be adjusted
with the speed regulator 11 and torque regula-
tor 10 depending on the type of material (values
shall be determined experimentally).
For different types of material (hard wood, damp
wood, etc.) the screw might go too deep or not
deep enough. In this case the shut-off torque
must be changed with regulator 10:
- The screw is not levelled - turn regulator 10 in
direction III;
- The screw has gone too deep - turn regulator
10 in direction I.
WARNING: In case of screwing/un-
screwing long bolts and screws there is a
danger of slipping the drill.
RECOMMENDATION fOR SCREWING
▪ Use the proper bits for screwing, with appro­
priate shape and size.
▪ In soft wood the suitable screws can be
screwed in without preliminary drilling a small
pilot hole;
▪ For hard wood preliminary drilling a small pilot
hole is necessary;
▪ For sunk­head screws the hole must be pre-
liminary spot-faced.
▪ For pivot screws, drill preliminary the seat for
the screw for approximately half its length.
INSERTING AND fASTENING DRILL
BITS
for three-jaw chuck drills:
Through turning the collar of the chuck 2 clock-
wise or anti-clockwise the jaws are posi tioned
so the drill bit shank can be inserted inside the
choke. By turning the collar of chuck 2 anti-
clockwise (looking towards the chuck) the jaws
tighten the drill bit shank. Fix the drill bit finally
in the chuck by means of the special chuck key,
tightening equally in all three bores.
for keyless-chuck drills:
Grip rear collar of keyless chuck and rotate front
collar until chuck is opened sufficiently for the
tool to be inserted. Grip the rear collar and man-
ually rotate the front collar until tight. An audible
8
EN
"click" indicates that the chuck has automatically
locked.
WARNING: Use only drill bits with
proper diameter, not exceeding the specified
in the name plate to avoid overloading the
machine.
REMOVING THE CHUCK
for three-jaw chuck drills:
Open the jaws of chuck 2 entirely. Unscrew the
left threaded securing screw 1 by a screwdriver.
Grip the place for fixing the spindle 3 by a span-
ner. Insert the special key for chuck tightening
in one of the three bores and rotating clockwise
using the key as lever, unwind chuck 2 from the
spindle.
for keyless-chuck drills:
Grip rear collar of keyless chuck and rotate front
collar until chuck is opened entirely. Using a
screw driver unwind the left-threaded securing
screw. Place a hex bit or a screw-driver bit into
the chuck and tighten it. Secure the place for
fixing the spindle 3 by a spanner and rotate the
chuck anti-clockwise using the free end of the
bit.
AUxILIARY HANDLE
Tighten the auxiliary handle 9 on journal 4 of the
drill. In the interests of safety, the auxiliary han-
dle 8 should always be used. The depth gauge 7
can be used for fixing the depth of drilled bores.
RECOMMENDATIONS fOR OPERA-
TION
Apply moderate pressure during drilling in con-
crete (approximately 100-120 N). Higher pres-
sure will not increase drilling efficiency, but it will
lead to decreasing the operation life of the ma-
chine. For machines with electronic speed con-
trol, drill with speed lower than the maximum,
suited to the material.
Use carbide tipped straight shank drill bits.
Take the drill out of the opening from time to time
to remove dust.
Watch out the stage of blunting of the bit and
change it if considerable decrease of efficiency
is observed.
Before drilling largediameter holes, drill a small
pilot hole.
The optimum capacity when drilling in concrete
is up to 16 mm, and the possible capacity is up
to 25 mm.
BU2 250 ● BUR2 250E ● BUR2 250CET