Starting Operation - Bosch GNF 20 CA Professional Manual Original

OBJ_BUCH-126-001.book Page 27 Tuesday, November 27, 2007 9:54 AM
Determining the Slot Width
The slot width results from the amount of spac-
er discs 19 between the two diamond cutting
discs 18 and the cutting width of the diamond
cutting discs.
The slot width is calculated as follows:
Slot width = Thickness of the spacer discs +
width of the diamond cutting discs.
The allowable slot width is shown in the section
"Technical Data".
The machine can be operated with one or two
diamond cutting discs.
Mounting the Clamping Assembly
(see figure A)
Set the mounting flange 17 onto the grinder
spindle 16. The mounting flange with its driving
feature must be properly seated on the grinding
spindle.
Place the diamond cutting disc 18 and the spac-
er discs 19 on the mounting flange 17.
Regardless of the requested slot width, all
spacer discs 19 provided must always be
mounted. Otherwise, the diamond cutting
disc 18 can become loose during operation
and lead to injuries.
Amount of required spacer discs:
GNF 20 CA: 5 pce., each 4 mm thick
GNF 35 CA: 3 pce., each 4 mm thick and 4 pce.,
each 6 mm thick.
At least one spacer disc 19 must be mounted be-
tween two diamond cutting discs 18.
When mounting the diamond cutting discs, en-
sure that the direction-of-rotation arrows on the
diamond cutting discs match with the rotation
rotation direction of the machine (see direction-
of-rotation arrow on the gear case).
Press the spindle lock button 9 to lock the grind-
ing spindle.
Screw on the clamping nut 20 and tighten it with
the two-pin spanner 1.
Swivel the cutting unit back again. Check the
locking system of the cutting unit by pulling the
handle.
When working with 2 diamond cutting discs 18,
always replace them in pairs.
See graphics page for the mounting sequence.
Bosch Power Tools
Operation
Pre-selecting the Cutting Depth
The cutting depth may only be pre-selected
when the machine is switched off.
The requested cutting depth can be pre-select-
ed with the depth stop 6.
Press the button for depth stop adjustment 5
and push the depth stop 6 to the requested cut-
ting depth on the cutting-depth scale 4. Release
button 5 again.
Ensure that the depth stop 6 is engaged again.

Starting Operation

Observe correct mains voltage! The voltage
of the power source must agree with the
voltage specified on the nameplate of the
machine. Power tools marked with 230 V
can also be operated with 220 V.
Switching On and Off
Before starting the machine, check if the
cutting unit has engaged in the upper posi-
tion. Otherwise the diamond cutting discs
can touch the workpiece, resulting in possi-
ble loss of control over the power tool when
switching on.
To start the power tool, push the On/Off switch
10 forwards.
To lock the On/Off switch 10, press the On/Off
switch 10 down at the front until it latches.
To switch off the power tool, release the On/Off
switch 10 or, if it is locked, briefly push down
the back of the On/Off switch 10 and then re-
lease it.
Check the diamond cutting discs before
use. The diamond cutting disc(s) must be
mounted properly and be able to rotate
freely. Carry out a test run for at least
30 seconds without any load. Do not use
diamond cutting discs that are damaged,
out-of-balance, or vibrate. Damaged dia-
mond cutting discs can rupture and lead to
injuries.
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