Bosch GTR Professional 550 Notice Originale page 17

Do not put the power tool down on its side. This could
u
permanently warp the sanding pad.
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.
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
speed setting 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.
Sanding Close to Edges (see figures E–F)
Thanks to the removable brush segment, you can reduce the
lateral distance between the wall/ceiling and the sanding
pad.
– Press and hold the locking mechanism (12) for the brush
segment (17).
– Swivel the brush segment (17) forwards and remove it.
– To insert, hook the brush segment (17) onto the oppos-
ite side of the locking mechanism (12), and swivel it to-
wards the sanding head (11) until it clicks into place.
Adjusting the Internal/External Airflow
Depending on the vacuum pressure, the perceived tool
weight can be reduced.
You can switch between different air flow operating modes
depending on the intended use. Turn the suction power ad-
justing lever (13) to one of the 3 positions.
Switch position Type of airflow
① External airflow Ideal for sanding
② Mixed external
and internal air-
flow
Bosch Power Tools
Switch position
Adjusting suction power
You can adjust the suction power to achieve your preferred
balance between sanding speed and suction power. This
regulation is only possible when the internal airflow is activ-
ated (position ③ in the table above).
Use the thumbwheel (1) to adjust the suction power.
– 1: Low suction power
– 6: High suction power
Start with a low suction power (position 1) and increase
slowly, until there is a noticeable contact pressure.
High suction power allows low-fatigue sanding of ceilings
and walls. An excessively high suction power can cause the
power tool to vibrate, which can make handling more diffi-
cult.
Errors – Causes and Corrective Measures
Cause
The drywall sander does not run smoothly or jolts across
the surface.
The suction effect is too
strong.
The bodyfiller material and/
or substrates are hard.
The removal rate of the material to be machined is too
high.
The drywall sander's speed is
Use
too high.
The suction effect on the dry-
walls at high sand-
wall sander is too strong.
ing speeds and
without vacuum
The bodyfiller material has a
pressure
high proportion of filler or is
very soft.
Medium sanding
performance with
vacuum pressure
The grit of the abrasive is too
effect
coarse.
The surface quality is not optimal.
The grit of the abrasive is too
coarse.
English | 17
Type of airflow Use
③ Mixed external Ideal for sanding
and internal air- ceilings at low
flow sanding speeds
but with high va-
cuum pressure
(suction power)
for a low perceived
weight
Corrective measure
Reduce the suction power or
switch to external dust ex-
traction, if necessary.
Reduce the suction power or
switch to external dust ex-
traction, if necessary.
Reduce the speed.
Reduce the speed.
Reduce the suction effect or
switch to external dust ex-
traction.
Switch on the external dust
extraction, set the suction
power thumbwheel to setting
6 and, in extreme cases, re-
duce the speed.
Use a sanding sheet with a
finer grit.
Use a sanding sheet with a
finer grit.
1 609 92A 6MX | (16.08.2021)