Working Advice - Bosch GSB 20-2 Professional Originalbetriebsanleitung

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Adjusting the Speed/Impact Frequency
(GSB 20-2 RE/GSB 20-2 RCE/GSB 20-2 RET)
The speed/impact rate of the switched on pow-
er tool can be variably adjusted, depending on
how far the On/Off switch 6 is pressed.
Light pressure on the On/Off switch 6 results in
low speed/impact rate. Further pressure on the
switch increases the speed/impact rate.
Preselecting the Speed/Impact Frequency
(GSB 20-2 RE)
With the thumbwheel for speed preselection 7,
the required speed/impact frequency can be
preselected even during operation.
The required speed/impact frequency depends
on the material and the working conditions, and
can be determined through practical testing.
Electronic Speed Preselection
(GSB 20-2 RCE/GSB 20-2 RET)
With the thumbwheel for electronic speed
preselection 3, the required speed/impact fre-
quency can be selected even if the machine is
running.
The required speed/impact frequency depends
on the material and the working conditions, and
can be determined through practical testing.
Constant Electronic Control
(GSB 20-2 RCE/GSB 20-2 RET)
The constant electronic control keeps the prese-
lected speed and impact rate nearly constant
between no-load and load conditions.
Electronic Torque Limitation/Speed Preselec-
tion (Torque Control) (GSB 20-2 RET)
Drilling with speed preselection:
Set the selector switch 4 to the
"Drilling" symbol. The required
speed can be selected with the
thumbwheel 3; it can also be adjust-
ed during operation.
1 609 929 T17 | (20.10.09)
Screwdriving with torque limita-
tion: Set the selector switch 4 to the
"Screwdriving" symbol. The effec-
tive torque at the drill spindle can be
variable adjusted with the thum-
bwheel 3 during operation:
I=low torque, III=high torque.
The maximum speed is automatically adapted to
the adjusted torque.
If the preselected torque is reached during
screwdriving, the machine switches off; the
drilling tool no longer rotates. If the load on the
machine is then removed with the On/Off
switch 6 still pressed, the drilling tool continues
to run only at very low speed for safety reasons.
After briefly releasing the On/Off switch 6, the
next screw can be driven in with the same
torque.
For screwdriving without torque
limitation, turn the thumbwheel 3 to
the right stop. This setting is re-
quired, when the torque in
position III is not sufficient.

Working Advice

Apply the power tool to the screw/nut only
when it is switched off. Rotating tool inserts
can slip off.
Tips
After longer periods of working at low speed, al-
low the machine to cool down by running it for
approx. 3 minutes at maximum speed with no
load.
For drilling in tiles, set the selector switch 2 to
the "Drilling" symbol. Do not switch over to the
symbol "Impact Drilling" or work with impact
until after drilling through the tile.
Use carbide tipped drill bits when working in
concrete, masonry and brick wall.
For drilling in metal, use only perfectly sharp-
ened HSS drill bits (HSS=high-speed steel). The
appropriate quality is guaranteed by the Bosch
accessories program.
Twist drills from 2.5–10 mm can easily be
sharpened with the drill bit sharpener (see ac-
cessories).
Bosch Power Tools