Working Advice - Bosch GWS 900-100 Professional Manual Original

OBJ_BUCH-2775-004.book Page 12 Monday, April 3, 2017 8:22 AM
12 | English
Switching On and Off
To start the power tool, push the On/Off switch 2 forwards.
To lock the On/Off switch 2, press the On/Off switch 2 down
at the front until it latches.
To switch off the power tool, release the On/Off switch 2 or,
if it is locked, briefly push down the back of the On/Off switch
2 and then release it.
 Check grinding tools before using. The grinding tool
must be mounted properly and be able to move freely.
Carry out a test run for at least one minute with no load.
Do not use damaged, out-of-centre or vibrating grind-
ing tools. Damaged grinding tools can burst and cause in-
juries.
To save energy, only switch the power tool on when using it.
Speed preselection (GWS 900-100 S/GWS 900-115 S/GWS 900-125 S)
The required speed can be preselected with the thumbwheel 3 (also while running).
The data in the following table are recommended values.
Material Application
Metal Removing paint
Metal Brushing, rust removal
Metal, masonry Grinding
Metal Rough grinding
Metal Cutting

Working Advice

 Before any work on the machine itself, pull the mains
plug.
 Exercise caution when cutting slots in structural walls;
see Section "Information on Structures".
 Clamp the workpiece if it does not remain stationary
due to its own weight.
 Do not strain the machine so heavily that it comes to a
standstill.
 After heavily straining the power tool, continue to run
it at no-load for several minutes to cool down the acces-
sory.
 Do not touch grinding and cutting discs before they
have cooled down. The discs can become very hot while
working.
 Do not use the power tool with a cut-off stand.
Rough Grinding
 Never use a cutting disc for roughing.
The best roughing results are achieved when setting the ma-
chine at an angle of 30° to 40°. Move the machine back and
forth with moderate pressure. In this manner, the workpiece
will not become too hot, does not discolour and no grooves
are formed.
Flap Disc
With the flap disc (accessory), curved surfaces and profiles
can be worked.
1 609 92A 3T4 | (3.4.17)
Restarting Protection (GWS 900-100 S/
GWS 900-115 S/GWS 900-125 S)
The restarting protection feature prevents uncontrolled re-
starting of the machine after an interruption in the power sup-
ply.
To restart the operation, switch the On/Off switch 2 to the
Off position and start the machine again.
Reduced starting current (GWS 900-100 S/
GWS 900-115 S/GWS 900-125 S)
The electronic reduced starting current limits the power con-
sumption when switching the tool on and enables operation
from a 13 ampere fuse.
Accessory
Sanding disc
Cup brush, sanding disc
Grinding disc
Grinding disc
Cutting disc
Flap discs have a considerably higher service life, lower noise
levels and lower sanding temperatures than conventional
sanding sheets.
Cutting Metal
 For cutting with bonded abrasives, always use the pro-
tection guard for cutting 15.
When cutting, work with moderate feed, adapted to the mate-
rial being cut. Do not exert pressure onto the cutting disc, tilt
or oscillate the machine.
Do not reduce the speed of running down cutting discs by ap-
plying sideward pressure.
When cutting profiles and square bar, it is best to start at the
smallest cross section.
Thumbwheel Position
2 – 3
3
4 – 6
6
6
The machine must al-
ways work in an up-
grinding motion. Other-
wise, the danger exists
of it being pushed un-
controlled out of the
cut.
Bosch Power Tools