Bosch GDB 350 WE Professional Manual Original página 20

20 | English
Check that the power tool is fitted securely in the drill
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holder.
To remove the power tool from the drill stand, carry out the
steps above in reverse order.
Spacer plate for drilling diameters of 300–350 mm
(see figure C)
The spacer plate (29) (accessory) must also be inserted in
order to drill holes of 300 mm to maximum 350 mm dia-
meter.
To do this, attach the machine adapter (25) to the spacer
plate (29) so that the feather keys (24) of the machine ad-
apter click into the corresponding grooves on the spacer
plate.
Then attach the spacer plate (29), including the machine
adapter (25), to the power tool so that the feather keys (31)
of the spacer plate click into the corresponding recesses on
the power tool. Insert the four screws (30) for the spacer
plate and tighten them using a hex key (size 6 mm).
Then mount the power tool on the drill stand as described
above.
Fixing the drill stand in place
Note: Fix the drill stand in place so that it is free of play. This
prevents the core bit jamming and segments from being torn
out.
Depending on the type and nature of the base material, fix
the drill stand to the intended site of the drill hole using an
anchor, vacuum or quick-clamping column.
Positioning the drill stand before fixing in place
Mark the centre of the hole you want to drill on the surface.
Mark the outer dimensions of the core bit you want to use,
using the centre of the hole as the centre of the bit.
Fix the drill stand (with power tool inserted) in place using
an anchor, vacuum or quick-clamping column so that the at-
tached core bit lines up with the marked dimensions.
Fixing with an anchor (see figure D)
Drill a separate attachment hole for fixing the drill stand in
place with an anchor (accessories) in masonry or concrete.
Distance between anchor hole and centre of planned
hole
Optimum
Possible
The following dimensions apply for the anchor hole:
Diameter
Masonry 20 mm
Concrete 16 mm
Insert a concrete anchor with expansion wedge or a masonry
anchor (32). Screw the quick-clamping spindle (33) into the
anchor.
Attach the drill stand and a washer and screw these on using
the wing nut (34). Tighten the wing nut according to the lev-
elling using an open-ended spanner (width across flats
27 mm).
1 609 92A 4NK | (21.01.2021)
Fastening by vacuum (accessory)
To fasten the drill stand by vacuum, you need a commercially
available vacuum pump and a Bosch vacuum set (access-
ory).
The vacuum pump must meet the following minimum re-
quirements:
Volume flow:
Vacuum at least:
The surface must be smooth and flat in order to fasten with
vacuum. Use on plaster or brickwork is not permitted.
Once the vacuum connection has been established, gently
attach the levelling screws (18) to the base material so that
the drill stand is in a rigid position and the sealing ring re-
laxes slightly. Otherwise the drill stand will sit very softly on
the sealing ring.
In order to connect the vacuum pump and Bosch vacuum
set, please read and follow the respective operating instruc-
tions.
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Fixing in place with a quick-clamping column
(see figure E)
You can fix the drill stand in place between the floor and ceil-
ing using a Bosch quick-clamping column (accessory). The
clamping capacity is 1.7 m to 3 m.
Place one end of the quick-clamping column on the base
plate of the drill stand. The contact surface on the ceiling for
the other end of the quick-clamping column must be suffi-
ciently stable so that it cannot slip.
To fix the quick-clamping column in place, read and follow
the operating instructions provided with it.
Levelling (does not apply for fastening by vacuum)
One by one, turn the levelling screws (18) in or out until the
spirit level (28) (if mounting vertically) is exactly aligned.
Then fix the drill stand firmly in place using an anchor attach-
ment or quick-clamping column.
Inserting/changing the core bit
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285 mm
275–375 mm
Inserting the core bit
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Depth
85 mm
50 mm
Clean the core bits before inserting them. Lightly grease the
thread of the core bit or spray it with corrosion inhibitor.
Screw a 1 1/4" UNC core bit (6) onto the drill spindle (7).
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The safety and operating instructions for the vacuum
pump and vacuum set must be strictly observed.
Before carrying out any work on the drill stand or drill,
during work breaks and when not using the drill stand,
secure the drill stand against unintentional movement
by tightening the parking brake.
Always examine the core bits before inserting them.
Only use core bits that are free of defects. Using dam-
aged or deformed core bits may result in dangerous situ-
ations.
Check that the core bit is fitted securely. Core bits that
are attached incorrectly or are not securely fixed in place
may come loose during operation, thereby putting you at
risk.
3
6 m /h
80 % (−800 mbar)
Bosch Power Tools