Bosch Professional GNA 3,5 Manual Original página 11

hold-down device. Push the hold-down device (12) onto the
sheet, leaving a little clearance (approx. 0.3 mm). Make sure
that the hold-down device is straight and not at an angle.
Retighten the screws (13).
Switching On and Off
To switch on the power tool, slide the on/off switch (5) for-
wards so that I appears on the switch.
To lock the on/off switch (5), push down on the front of the
switch as well.
To switch off the power tool, release the on/off switch (5).
When the on/off switch is locked, press down on the back of
the switch and then release it.
Working Advice
Pull the plug out of the socket before carrying out any
u
work on the power tool.
This power tool is not suitable for bench-mounted use.
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It must not be clamped into a vice or fastened to a work-
bench, for example.
Wear protective gloves during work and pay particu-
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lar attention to the cord. Sharp burrs develop on the cut
sheets; these can cause injury or damage the cord.
Exercise caution when handling the cutting chips. The
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chips have sharp tips that can cause injuries.
Apply the power tool to the workpiece only when switched
on. Always hold the power tool vertical to the surface of the
steel sheet and do not tilt it.
The cut is made as the punch moves downwards. Guide the
power tool evenly, pushing it gently in the cutting direction.
Applying too much pressure to the power tool will signific-
antly reduce the service life of application tools and can
damage the power tool.
The power tool operates more quietly when it is raised
slightly during cutting. If the punch jams during cutting,
switch the power tool off, lubricate the punch and release
the sheet. Do not use force to do this, as this will damage the
punch and the die.
Maximum steel sheet cutting capacity
The maximum steel sheet cutting capacity d
the strength properties of the material to be cut.
The power tool allows for cutting of metal sheet to the follow-
ing thicknesses:
Material max. strength
(N/mm
Steel 400
600
800
Aluminium 200
Lubricating/cooling the punch
To extend the service life of the punch (10), a lubricating
agent with good cooling properties (e.g. cutting oil) should
be used.
Bosch Power Tools
depends on
max
d
max
2
) (mm)
3.5
2.4
1.6
4.0
Apply a line of lubricant to the top side of the metal sheet
along the intended cutting line.
For long periods of continual use or for work with high fric-
tional wear (e.g. when cutting aluminium), the application
tool should be immersed in a container of lubricant at regular
intervals.
Cutting along a scribe line or with a template
You can use the projection on the hold-down device (12) as
the cut mark when cutting along a scribe line.
Straight cuts are carried out easier when the power tool is
guided alongside a rule.
Contours can be cut by guiding the power tool along a tem-
plate.
For inside cuts, a hole with a diameter of 41 mm must be
pre-drilled.
Maintenance and Service
Maintenance and Cleaning
Pull the plug out of the socket before carrying out any
u
work on the power tool.
To ensure safe and efficient operation, always keep
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the power tool and the ventilation slots clean.
In order to avoid safety hazards, if the power supply cord
needs to be replaced, this must be done by Bosch or by an
after-sales service centre that is authorised to repair Bosch
power tools.
Clean and lubricate the punch (10), die (14) and guide
plate (11) after every three hours in operation.
Change the punch, die and guide plate in good time when
worn. Only sharp tools achieve a good cutting quality and
make the power tool last longer.
Changing the die
Loosen and remove the two screws (9). Insert a new
die (14) and tighten it firmly with the screws.
Worn dies 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 (11), remove the die (14) as de-
scribed above. Then loosen and remove the screws (13) on
the hold-down device. Remove the hold-down device (12)
and the guide plate.
Insert a new guide plate (11). Secure the die (14) with the
screws (9) and secure the hold-down device (12) with the
screws (13). Tighten all screws firmly.
Changing the punch
Insert the hex key (4) into the screw head of the punch posi-
tioner (16). Turn the punch positioner until the screw (7) is
in the exact centre of the hole (8) on the die holder. Remove
the hex key from the punch positioner.
Remove the die (14), the hold-down device (12) and the
guide plate (11) as described above.
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1 609 92A 505 | (24.06.2019)