Bosch GSB 550-2 PROFESSIONAL Operating Instructions Manual page 6

2 609 140 164 - Buch Seite 3 Mittwoch, 14. Januar 2004 11:57 11
Initial Operation
Always use the correct voltage: The voltage of
the power source must agree with the values on
the nameplate of the machine.
Switching On and Off
To start the unit, press the On/Off switch 6 .
GSB 550 RE: The machine runs
with variable speed between 0 and
maximum depending on the pres-
sure applied to the On/Off switch 6 .
Light pressure results in a low rota-
tional speed, thus allowing smooth,
controlled starts. Do not load the
machine so heavily that it comes to
a standstill.
Lock the pressed On/Off switch 6 by pressing
the lock-on button 4 .
To switch the unit off , release the On/Off
switch 6 or press and then release it.
Speed Selection (GSB 550 RE)
With the thumbwheel 5, the required speed can
be selected even if the machine is running.
The required speed depends on the material and
can be determined with practical trials.
After working with the machine for long periods at
low speed, allow it to cool by letting it run for ap-
prox. 3 minutes at maximum speed with no load.
Two-step switch (GSB 550-2)
Two rotational speed ranges can be selected with
On/Off switch 6. The machine switches from the
first to the second rotational speed step after a
perceptible pressure point has been exceeded:
Rotational speed step I:
Rotational speed step II: 3 000 rpm
The On/Off switch can be locked in either of the
rotational speed steps by means of locking but-
ton 4.
6 • 2 609 140 164 • TMS • 07.01.04
2 500 rpm
English - 3
Changing the Rotational Direction
(GSB 550 RE)
Operate the rotational
switch 7 only at a standstill.
Set the rotational direction selector 7 to R (right
or clockwise) or L (left or counter clockwise).
(The rotational direction selector 7 is locked
when the On/Off switch 6 is activated).
The left-hand rotation enables screws or nuts to
be unscrewed.
Drilling and Impact Drilling
Drilling and Screwing In
Set the selector switch 3 to the "Drilling
and Screwing" symbol.
Impact Drilling
Set the selector switch 3 to the "Ham-
mer drilling" symbol.
The selector switch 3 engages noticeably and
can be actuated with the machine running.
Replacing the Chuck
Before any work on the machine itself, pull
the power plug.
Key Chuck (see figure
To unscrew key chuck 12, position open-end
spanner (SW 13) on key face.
Place the chuck key in one of the 3 bores and
loosen the chuck by turning it to the left using the
key as a lever. If the key chuck is frozen in place,
a tap on the chuck key should loosen it.
Keyless Chuck
If the keyless chuck is too tight to unscrew, clamp
the Allen key, with the short shaft first, in the key-
less chuck 1. Loosen the chuck by giving the
Allen key a slight knock on the long shaft, and un-
screw.
direction
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