Speed Preselection - Bosch GSB 20-2 PROFESSIONAL Instrucciones De Servicio

Speed Preselection

GSB 20-2 RE: The required speed can be prese-
lected with the thumbwheel 8 (also while run-
ning).
GSB 20-2 RCE/GSB 20-2 RET: The required
speed can be pre-selected with the power control
thumbwheel 3 (also with the machine running).
Constant Electronic Control
(GSB 20-2 RCE/GSB 20-2 RET)
The Constant Electronics with "Tachogenerator"
keep the set speed almost constant, even under
load.
Drilling, Screwdriving and
Impact Drilling
Drilling and Screwdriving
Set the selector switch 2 to the "Drilling
and Screwdriving" symbol.
Impact Drilling
Set the selector switch 2 to the "Impact
Drilling" symbol.
The selector switch 2 engages noticeably and
can be actuated with the machine running.
Electronic Torque Limitation/
Speed Preselection
(Power Control GSB 20-2 RET)
Drilling with speed preselection
Set the selector switch 4 to the "Drill-
ing" symbol. The required speed can
be pre-selected with the thumb-
wheel 3 (also during running).
Screwdriving with torque limitation
Set the selector switch 4 to the
"Screwdriving" symbol. The effective
torque at the drill spindle can be var-
iably adjusted with the thumb-
wheel 3:
I = low torque
III = high torque
The maximum speed is automatically adapted to
the adjusted torque.
15 • 2 609 932 256 • 03.10
If the pre-selected torque is reached during
screwdriving, the machine switches off and
stops. If the load on the machine is then removed
with the On/Off switch 7 still pressed, the contin-
ued run is at very low speed for safety reasons.
Briefly releasing the On/Off switch 7 automati-
cally restores the previous operating condition,
so that the next screw will be driven in with the
same torque.
Screwdriving without torque limitation
When the thumbwheel 3 is turned all
the way to the right, the torque limita-
tion is not effective. This setting is re-
quired, e. g. when the power in posi-
tion III is not sufficient.
Replacing the Drill Chuck
(see figures
■ Before any work on the machine itself, pull
the mains plug.
Before changing the drill chuck, disassemble the
auxiliary handle 12.
For machines with drill spindle lock (Auto-Lock),
set the gear selector 10 to the middle position be-
tween 1. and 2. gear.
In order to lock the drill spindle, insert a steel pin,
Ø 4 mm with a length of approx. 50 mm into the
hole on the spindle collar. Turn the drill spindle
until the steel pin can be inserted approx. 40 mm
to the stop.
Clamp the short end of an Allen key in the chuck.
Place the machine on a stable surface (e. g.
workbench). Hold the machine firmly and loosen
the chuck by turning to the left, as when unscrew-
ing a screw (
the long end of the Allen key 18 a sharp blow.
For machines with a keyless chuck, an open-end
spanner, size 19 mm can be placed on the drill
chuck instead of the Allen key.
The drill chuck is mounted in reverse order (
☞
After mounting has been completed, re-
move the steel pin from out of the hole
again.
The chuck must be tightened with a
torque of approx. 35 – 40 Nm.
English - 4
– )
G H
➊
). Loosen a tight chuck by giving
➋
).