Würth MKB 35 Traducción Del Manual De Instrucciones De Servicio Original página 18

Special considerations when dealing
with switchable permanent magnets
There is a magnetic surface on the underside of the
machine which generates the adhesive force using
magnetic flux when in an activated condition. The
magnet can be activated independently of the mains
voltage by pushing the lever down. To release, push
the black safety tab inwards with the ball of the
thumb, and pull the lever upwards. The machine
stays stuck to the workpiece – even when electricity
is cut.
Material thickness
The magnetic flux of the TML permanent
magnet requires a minimum material
thickness of 8 mm to flow through the
whole of the workpiece. If this material
thickness is not available, the maximum
adhesive force is reduced in relation
to the material thickness. Conventional
electric and permanent magnets have a
very deep-reaching magnetic field, sim-
ilar to the taproot of a tree, and require
a material thickness of more than 25
mm to achieve maximum adhesive force.
The compact magnetic field of the TML
magnets is similar to the shallow root and
achieves maximum adhesive force even
with low material thicknesses, meaning
you can drill on thin plates from 3–4 mm
with adequate adhesive force.
Material
The working load limit of the perma-
nent magnets is determined on S235
material. Steels with a high proportion of
carbon or a structure modified through
heat treatment have low adhesive force.
Foamed or pore-ridden cast components
also have low adhesive force.
Material
Unalloyed steel
(0.1-0.3% C-content)
Unalloyed steel
(0.3-0.5% C-content)
Cast steel
Grey cast iron
Nickel
Stainless steel, aluminium,
brass
18
Magnetic force
in %
100
90–95
90
45
11
0
Surface condition
If an air gap emerges between the magnet and
the workpiece, this reduces the adhesive force. For
example, matter such as paint, rust, scale, surface
coatings, grease and similar substances form a gap,
meaning an air gap, between the workpiece and the
switchable magnet and reduce the adhesive force.
Attention!
The high-performance permanent magnets inte-
grated within the magnet irreversibly lose their
magnetic properties from a temperature of more
than 80°C so that, even when the magnet has
subsequently cooled down, full adhesive force will
never be achieved again.
MKB 35
▸
Plug in the mains plug.
▸
Insert the core drill into the tool holder [12] on
the motor's work spindle.
▸
Check the tool is clamped in firmly and with
positional accuracy.
▸
Switch magnetic switch [16] to I, so that the
magnet is activated and the holding of the drill
stand is ensured.
▸
Switch on the drive motor [14] by pressing the
switch MOTOR I [10].
▸
Turning the star handle [1] moves the motor and
the rotating drill slowly towards the workpiece.
Ensure sufficient cooling during the drilling
process.
▸
Once drilling operations are over, move the
motor away from the workpiece by turning the
star handle.
▸
Deactivate the motor with the red
button MOTOR O [9] on the operating panel.
▸
Once the motor has come to a complete stand-
still, remove shavings and other drill residues.
▸
To deactivate the magnet, set the magnetic
switch [16] to O.
▸
Then clean the underside of the magnet of shav-
ings and other adhesive residues.