Bosch GEX Professional 125 A Manual Original página 16

OBJ_BUCH-424-005.book Page 16 Tuesday, December 3, 2013 8:43 AM
16 | English
Internal Dust Extraction with Dust Bag (see figure E)
For small sanding jobs, a dust bag (accessory) 19 can be con-
nected.
Before mounting the dust bag 19, pull out the plastic slider
13. Slide the dust-bag sleeve firmly over the extraction outlet
14. Pay attention that the plastic slider 13 engages in the
holder intended for it on the dust bag 19.
To maintain optimum dust collection, empty the dust bag 19
in good time.
Auxiliary Handle
The auxiliary handle 1 enables convenient handling and opti-
mal distribution of power, especially at high removal rates.
Fasten the auxiliary handle 1 with screw 2 to the casing.
Operation
Starting Operation
 Observe correct mains voltage! The voltage of the pow-
er source must agree with the voltage specified on the
nameplate of the machine. Power tools marked with
230 V can also be operated with 220 V.
Switching On and Off
To start the machine, press the On/Off switch 4 and keep it
pressed. To lock the pressed On/Off switch 4, press the lock-on button
5.
To switch off the machine, release the On/Off switch 4 or
when it is locked with the lock-on button 5, briefly press the
On/Off switch 4 and then release it.
To save energy, only switch the power tool on when using it.
Preselecting the Orbital Stroke Rate
(GEX 125 AC/GEX 150 AC)
With the thumbwheel for preselection of the orbital stroke
rate 3, you can preselect the required orbital stroke rate, even
during operation.
1 –2 Low stroke rate
3 –4 Medium stroke rate
5 –6 High stroke rate
The required stroke rate depends on the material and the
working conditions and can be determined through practical
testing.
The constant electronic control keeps the stroke rate almost
constant under no-load or load conditions and ensures a uni-
form working performance.
After longer periods of working at low stroke rate, allow the
machine to cool down by running it for approx. 3 minutes at
maximum stroke rate with no load.
Sanding Plate Brake
An integrated sanding plate brake reduces the stroke rate
when running at no-load so that scoring is prevented when
placing the machine onto the workpiece. If the no-load stroke rate continuously increases over the
course of time, then the sanding plate is damaged and must
2 609 932 908 | (3.12.13)
be replaced or the sanding plate brake is worn. A worn sand-
ing plate brake must be replaced by an authorised after-sales
service agent for Bosch power tools.
Working Advice
 Before any work on the machine itself, pull the mains
plug.
 Wait until the machine has come to a standstill before
placing it down.
Sanding Surfaces
Switch the machine on, place it with the complete sanding
surface on the surface to be worked and move the machine
with moderate pressure over the workpiece.
The removal capacity and the sanding pattern are mainly de-
termined by the selection of the sanding sheet, the preselect-
ed orbital stroke rate (GEX 125 AC/GEX 150 AC) and the ap-
plied pressure.
Only flawless sanding sheets achieve good sanding capacity
and extend the service life of the machine.
Pay attention to apply uniform sanding pressure; this increas-
es the working life of the sanding sheets.
Intensifiying the sanding pressure does not lead to an in-
crease of the sanding capacity, but to increased wear of the
machine and the sanding sheet.
A sanding sheet that has been used for metal should not be
used for other materials.
Use only original Bosch sanding accessories.
Rough Sanding
Attach a sanding sheet with coarse grain.
Apply only light pressure to the machine so that it runs at a
higher stroke rate and high material removal is achieved.
Fine Sanding
Attach a sanding sheet with fine grain.
By lightly varying the application pressure or changing the or-
bital stroke rate (GEX 125 AC/GEX 150 AC), the sanding
plate stroke rate can be reduced whereby the orbital action is
maintained.
With moderate pressure, move the machine in a circular pat-
tern or alternately in lengthwise and crosswise directions
over the workpiece. Do not tilt the machine to avoid sanding
through the workpiece (e. g. when sanding veneer).
After finishing the working procedure, switch the power tool
off.
Polishing (GEX 125 AC/GEX 150 AC)
For the polishing of weathered paint or buffing out scratches
(e.g., acrylic glass), the machine can be equipped with appro-
priate polishing accessories such as lamb's wool bonnet, pol-
ishing felt or sponge (accessories).
Select a low stroke rate (setting 1 –2) for polishing in order to
avoid excessive heating of the surface.
Apply the polish onto a somewhat smaller surface than you in-
tend to polish. Work the polishing agent in with a suitable pol-
ishing tool applying it crosswise or with circular motion and
moderate pressure.
Bosch Power Tools