Weka DK26 Notice De L'utilisateur page 15

4.6 Friction clutch
The integrated friction clutch protects operating personnel, the machine and the tool against high
mechanical overloads.
Please ensure that the release time of the clutch is not more than 3 - 4 seconds, because
otherwise wear and heat will increase rapidly.
5. P U T T I N G I N T O O P E R A T I O N
5.1 Diamond drill bit
The tool fixture of the DK26/28/32/34 consists of a thread 1 ¼" UNC, respectively of a combination of 1
1/4" male and G1/2" female. Only use suitable high quality diamond tools.
Use sharp tools and ensure that the diamond segments are sufficiently larger than the inner and outer
diameter of the drill bit tube.
Apply water-resistant grease to the tool thread so that the tool can be easily loosened.
Ensure that the radial run out at the diamond segments of the drill bit is no greater than 1 mm
(eccentricity).
Only use suitable wrenches for changing the core bit. Thereby hold the drilling spindle with another
wrench.
Never use a hammer or something similar to open the core bit. If necessary elongate the
wrench.
5.2 Drilling
Since the rig is not included in the delivery, only a few important features are noted here.
Please adhere to the operating instructions for the drill rig.
Fixing methods
Dowel fixing, vacuum fixing, bracing.
The most common method of fixing is dowel fixing. Use metal dowels if at all possible. The diameter of the
dowels must be at least 12 mm.
With vacuum fixing, ensure there is a sufficiently great vacuum. Make sure that the sealing rings are not
worn out.
Ensure that the rig is only rigid when the sealing ring is relaxed via the jackscrews on the base of the rig.
Set the volume of water at the ball valve (1a) so, that the waste material is completely flushed from the drill
hole. If drilling mud forms round the drill hole, you are not using enough water.
Use force as required. If you do not, the diamonds will tend to "polish". In this case the rate of advance will
fall constantly until cutting finally stops.
Sometimes the segments can be resharpened again by using an SiC grindstone.
Take care that the drill bit does not vibrate, otherwise the diamonds can be tugged out their bond.
When drilling through iron reinforcements, use a greater initial pressure and the next lower gear.
If the drill blocks, do not try to loosen it by switching the machine on and off. Switch the machine off
immediately and try to loosen the drill bit by turning right and left using a suitable wrench. Carefully remove
the machine from the borehole.
6. M A I N T E N A N C E
You must remove the mains plug from the supply socket before beginning any maintenance
or repair work.
Clean the machine with a dry or moist cleaning-rag and not with a jet of water. Make sure that no water
gets into the motor or the switch box. Ensure that the ventilation slots are always clean. Clean and grease
the tool thread, too.
Damaged PRCDs, cords and plugs have to be repaired or exchanged exclusively in an authorized repair
station (www.weka-elektrowerkzeuge.de).
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