Maintenance And Service; Maintenance And Cleaning - Bosch GNA 3,5 Professional Manual Original

OBJ_BUCH-101-002.book Page 15 Tuesday, October 9, 2007 9:18 AM
Cutting along a Cutting Mark or with a Guide
The projection on the hold down guide 12 serves
as a cutting mark after having made the incipient
crack.
Straight cuts are carried out easier when the ma-
chine is guided alongside a rule.
For inside cuts, pre-drilling a hole with a diame-
ter of 41 mm is necessary.

Maintenance and Service

Maintenance and Cleaning

Before any work on the machine itself, pull
the mains plug.
For safe and proper working, always keep
the machine and ventilation slots clean.
Clean and lubricate the punch 10, die 14 and
guide plate 11 every 3 operating hours.
Change the punch, die and guide plate in good
time when worn. Only sharp tools produce a
good cutting quality and make the machine last
longer.
Changing the Die
Loosen and remove both screws 9. Insert a new
die and tighten it firmly with the screws 9.
A worn die must not be reground.
Changing the Guide Plate
The guide plate 11 is used to protect the die
holder 15.
To change the guide plate, remove the die 14 (re-
fer to "Changing the Die"). Loosen and remove
the screws 13 on the hold down guide. Remove
the hold down guide 12 and the guide plate 11.
Insert a new guide plate. Attach the die with the
screws 9 and the hold down guide via the screws
13. Tighten the screws.
Bosch Power Tools
Changing the Punch
Insert the allen key 4 into the screw head of the
punch adjustment screw 16. Turn the adjustment
screw until it 7 is exact centre of the borehole 8
at the die holder. Remove the allen key from the
punch adjustment screw 16.
Remove the die 14 (refer to "Changing the Die"
as well as the hold down guide 12 and the guide
plate 11 (refer to "Changing the Guide Plate").
Loosen the screw 7 of the punch fastener and
pull out the punch 10 downward. Lubricate the
new or the reground punch properly and insert it
from underneath. Tighten the screw 7 again.
Attach the guide plate 11 and the hold down
guide 12 as well as the die 14 (refer to "Changing
the Guide Plate" as well as "Changing the Die").
Regrinding the Punch
In most cases, regrinding the punch in good time
(e.g. with a diamond disc) can usually prevent
the punch from breaking out. Heavily damaged
punches may not be reground.
The punch may not be reground by more than
1 mm. Grinding may be carried out only along-
side the cutting surface and at exactly 90° to the
centre axis.
Set a light edge to the cutting edge of the punch
using a fine whetstone.
WARNING! Important instructions for connect-
ing a new 3-pin plug to the 2-wire cable.
The wires in the cable are coloured according to
the following code:
Do not connect the blue or brown wire to the
earth terminal of the plug.
Important: If for any reason the moulded plug is
removed from the cable of this power tool, it
must be disposed of safely.
English | 15
1 609 929 M47 | (9.10.07)