Starting Operation; Switching On/Off; Working Advice - Bosch GEX 125-1 A Professional Manual Original

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External dust extraction (see figure D)
Fit a dust extraction hose (10) onto the extraction outlet (8).
Connect the dust extraction hose (10) to an extractor. You
will find an overview of connecting to various dust extractors
at the beginning of these operating instructions.
The dust extractor must be suitable for the material being
worked.
When extracting dry dust that is especially detrimental to
health or carcinogenic, use a special dust extractor.
Operation

Starting Operation

Pay attention to the mains voltage. The voltage of the
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power source must match the voltage specified on the
rating plate of the power tool. Power tools marked
230 V can also be operated at 220 V.
Products that are only sold in AUS and NZ: Use a resid-
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ual current device (RCD) with a nominal residual current
of 30 mA or less.

Switching On/Off

Make sure that you are able to press the On/Off switch
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without releasing the handle.
To switch on the power tool, tilt the on/off switch (1) to-
ward the right to the "I" position.
To switch off the power tool, tilt the on/off switch (1) to-
ward the left to the "O" position.
Preselecting the orbital stroke rate (GEX 125-1 AE)
You can even preselect the orbital stroke rate during opera-
tion using the necessary orbital stroke rate preselection
thumbwheel (2).
1–2 Low orbital stroke rate
3–4 Medium orbital stroke rate
5–6 High orbital stroke rate
The required orbital stroke rate is dependent on the material
and the work conditions and can be determined using prac-
tical tests.
After working at a low orbital stoke rate for an extended
period, you should operate the power tool at the maximum
orbital stroke rate for approximately three minutes without
load to cool it down.
Sanding Plate Brake
An integrated sanding pad brake reduces the orbital stroke
rate when running without load to prevent scoring when the
power tool is placed on the workpiece.
If the no-load orbital stroke rate constantly increases over
time, this means that the sanding pad is damaged and must
be replaced, or that the sanding pad brake is worn. A worn
sanding pad brake must be replaced by an after-sales ser-
vice centre authorised to work with Bosch power tools.
1 609 92A 4AG | (22.05.2018)

Working Advice

Pull the plug out of the socket before carrying out any
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work on the power tool.
Always wait until the power tool has come to a com-
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plete stop before placing it down.
This power tool is not suitable for bench-mounted use.
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It must not be clamped into a vice or fastened to a work-
bench, for example.
For fatigue-free work, you can hold the power tool from
above, from the side or from the front, depending on the ap-
plication (see figure E).
Sanding Surfaces
Switch the power tool on, place the entire sanding surface
against the surface of the workpiece and apply moderate
pressure as you move the sander over the workpiece.
The material removal rate and sanding result are primarily
determined by the choice of sanding sheet, the preselected
orbital stroke rate level and the contact pressure.
Only immaculate sanding sheets achieve good sanding per-
formance and make the power tool last longer.
Be sure to apply consistent contact pressure in order to in-
crease the lifetime of the sanding sheets.
Excessively increasing the contact pressure will not lead to
increased sanding performance, rather it will cause more
severe wear of the power tool and of the sanding sheet.
Do not use a sanding sheet for other materials after it has
been used to work on metal.
Use only original Bosch sanding accessories.
Rough Sanding
Attach a coarse grit sanding sheet.
Apply only light pressure to the power tool so that it runs at a
higher orbital stroke rate and a higher material removal rate
is achieved.
Fine Sanding
Attach a fine grit sanding sheet.
You can reduce the sanding plate orbital stroke rate by
lightly varying the contact pressure or changing the orbital
stroke rate level; the random orbit motion will be retained.
Move the power tool with moderate pressure flat on the
workpiece in a circular motion or alternately along and
across it. Do not tilt the power tool in order to avoid sanding
through the workpiece, e.g. veneers.
Switch the power tool off after completing operation.
Polishing
For polishing weathered lacquers and redressing scratches
(e.g. acrylic glass), the power tool can be fitted with an ap-
propriate polishing tool, e.g. lambswool bonnet, polishing
felt or polishing sponge (accessory).
Select a low orbital stroke rate (level 1–2) when polishing in
order to avoid heating up the surface excessively.
Apply the polish to an area slightly smaller than the area
which you intend to polish. Using the appropriate polishing
tool, work in the polish with either linear or circular move-
ments and with moderate pressure.
Bosch Power Tools