Bosch GCR 350 Professional Manual Original página 12

OBJ_BUCH-2255-002.book Page 12 Thursday, August 25, 2016 3:08 PM
12 | English
Fold the drill onto the drill fixture  and reinsert the eccentric
bolt 3. Tighten the eccentric bolt 3 using the star handle 4.
Slide the star handle 4 right or left onto the feed pinion 15 in
order to drill.
 Check the tight seating of the drill in the drill fixture.
To remove the drill from the drill stand, complete the steps in
reverse order.
Spacer Plate for Drilling Diameters of 300–350 mm
(see figure C)
The spacer plate 18 (accessory) has to be additionally insert-
ed in order to drill holes of 300 mm to maximum 350 mm
diameter.
To do so, attach the machine adapter 14 to the spacer plate
18 so that the feather keys 13 of the machine adapter engage
into the corresponding slots on the spacer plate.
Then attach the spacer plate 18 including machine adapter
14 to the drill so that the feather keys 20 of the spacer plate
engage into the corresponding recesses of the drill. Insert the
four screws 19 of the spacer plate and tighten them using a
hex key (size 6 mm).
Then mount the drill on the drill stand as described above.
Fastening the Drill Stand
Note: Fasten the drill stand free from play to prevent jamming
of the core bit and the tearing out of segments.
Depending on the type and nature of the structural material,
fasten the drill stand where the bore hole is intended using an
anchor, with vacuum or with the quick-clamping column.
Positioning the Drill Stand before Fastening
Mark the centre of the bore hole you want to drill on the surface.
Mark the outer dimensions of the core bit you want to drill with,
using the centre of the bore hole as the centre of the bit.
Fasten the drill stand (with drill inserted) using anchors, vac-
uum or quick-clamping column so that the mounted core bit is
aligned with the marked dimensions.
Fastening with Anchor (see figure D)
For fastening of the drill stand to brickwork or concrete with
anchor (accessory), drill a separate anchor hole.
Clearance from anchor hole–centre of the intended bore
hole
optimal 285 mm
possible 275–375 mm
The following dimensions apply for the anchor hole:
Diameter
Brickwork 20 mm
Concrete 16 mm
Insert a concrete hammer-drive anchor or a brickwork anchor
21. Screw the quick-clamping spindle 22 into the anchor.
Position the drill stand, attach a washer, and then screw to-
gether with the wing nut 23. After levelling (see "Levelling"),
tighten the wing nut using an open-end spanner, size 27 mm.
1 609 92A 3A4 | (25.8.16)
Fastening with Vacuum (Accessory)
To fasten the drill stand with vacuum, you require a conven-
tional vacuum pump and a Bosch vacuum set (accessory).
The vacuum pump must meet the following minimum require-
ments:
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, apply the
levelling screws 7 lightly to the surface so that the drill stand
is in a rigid position and the sealing ring relaxes slightly. Oth-
erwise the drill stand will sit very softly on the sealing ring.
Read and observe the operating instructions of the vacuum
pump and Bosch vacuum set in order to connect them.
 The safety and operating instructions for the vacuum
pump and vacuum set are to be strictly observed!
Fastening with a Quick-clamping Column (see figure E)
You can fasten the drill stand between the floor and ceiling us-
ing a Bosch quick-clamping column (accessory). The clamp-
ing range is 1.7 m to 3 m.
Place one end of the quick-clamping column on the bottom
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 and resistant to slipping.
For fastening the quick-clamping column, read and observe
its operating instructions.
Levelling (does not apply for fastening with vacuum)
Turn the levelling screws 7 in or out individually until the spirit
level 17 (when mounting vertically) is precisely aligned.
Now, firmly fasten the drill stand with anchor attachment or
with the quick-clamping column.
Operation
 Disconnect the plug from the power source before
making any adjustments or changing accessories.
Starting drills accidentally is the cause of some accidents.
 After each adjustment on the drill stand, firmly retight-
en all screws.
Drilling-angle Adjustment
Loosen the cap nut 6 using the star handle 4.
Set the drill stand to the required drilling angle using the drill-
ing-angle scale 2. Observe the arrow next to the cap nut 6 for
the exact setting.
Depth
Tighten the cap nut 6 hand-tight using the star handle 4.
85 mm
 The drill stand must not be inserted until the cap nut 6
50 mm
of the angle adjustment has been retightened.
Water Extraction
You require a water collection ring and a wet/dry vacuum
cleaner (both accessories) to collect the water escaping from
the bore hole during wet drilling.
3
6 m /h
80 % (–800 mbar)
Bosch Power Tools