Setting Up The Bit Grinding Unit; Positioning The Bit; Grinding; Angle Of The Bit - KEF SLIBETTE 6 Bedienungsanleitung

2.5.1 Setting up the Bit Grinding Unit

Loosen the locking screw (17) and turn the arm (1) so that the nut (13) can be unscrewed and
the shaft (10) taken out of the bit grinding unit and put into the machine, where the shaft (10)
is inserted so that the threaded section is turned away from the machine. Then tighten the
Allen screws. Put the compression spring (11) onto the shaft (10) (position the spacer (34) on
the shaft at PSD 5) and put the rest of the bit grinding unit on the shaft (10). Attach the
protective cover (12) and thrust bearing (20), and finally tighten the nut (13). 1 Allen key (34)
is included in the kit. Insert the Allen bolt (19) from the front, and then tighten it (19). The arm
(1) of the bit grinding unit B must be adjusted so that +/- (31) lines up with the markings on
the arm (1).

2.5.2 Positioning the bit

Loosen the adjustment screw (7) and completely unscrew it. Then loosen the clamping screw
(16), place the bit in the V-groove, and push the clamp (5) forward to touch the bit. Tighten
the clamping screw (16) again.
Now use your thumb to turn the bit to the right so that one cutting edge of the bit touches the
outer side of the stop (8). Use the adjustment screw (7) to make fine adjustments to the
position. Pick the bit up and start the machine.

2.5.3 Grinding

Take the arm (1) in your hand and loosen the locking screw (17). Then turn the arm (1) back
and place the bit in the V-groove, holding it down with your thumb while at the same time
turning it forwards.
Turn the arm (1) with your other hand using rapid movements (reduces blueing) from one end
position to the other, and then use your fingers to turn the bit 180°. Repeat these movements
until there are no more sparks, then adjust the adjustment screw (7) and continue the
interactive grinding of the blades. Repeat this until the bit achieves the correct angle.
Only bits with symmetrical tips can drill holes at the desired position, and you must therefore
finish by fine grinding both blades a few times until there are no more sparks, and without
performing tightening actions using the adjustment screw (7).

2.5.4 Angle of the bit

Angle of the tip:
Chisel edge angle: Perform grinding so that the chisel edge angle is approximately 55°.
See Fig. II
Clearance angle:
For bits over 25 mm it may be necessary to reduce the length of the chisel edge
(see Fig. IV), as a large chisel edge places a large load on the drill.
Always keep the V-groove as clean of grinding dust as possible. Ensure there is good
working light. Follow standard safety rules and regulations for grinders. Avoid unnecessary
heating of the bit tip when grinding, e.g. by keeping the grinding wheel true and using a visible
grain.
The bit grinding unit is for grinding bits with tip angles of 116-118°, which are those
most frequently used. The angle of the tip cannot be changed by adjusting the bit
grinding unit.
Generally speaking, the clearance angle
should be 6-8°. See Fig III. As stated
previously, it will be larger if the stop is more
than 1-1.5 mm from the grinding wheel. If the
clearance angle is to be changed, the arm
can be adjusted using + or -.
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