Weka DK 42 B Instrucciones De Servicio página 15

4.6 Gear change
The DK42B/DK52 is fitted with a 3-speed gear.
Never use force to the gear change grip, and only change the speed when the machine is decelerating
or has stopped. Always select the appropriate speed for the drill diameter (see table and rating plate on
the machine).
4.7 Safety clutch
The integrated friction clutch protects the operator, 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, as otherwise wear
and heat will increase rapidly.
Type of machine
Release torque / safety clutch
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 DK42B/DK52´s tool fixture consists of a shaft with a female threat of 1 ¼" UNC. Only use suitable
high-quality diamond tools.
Only use appropriate diamond 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 on 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 pay attention to the operating instructions for the rig.
Fixing methods
Dowel fixing, bracing.
The most common method of fixing is dowel fixing. Use only metal dowels.
It is also possible to fasten the drill stand with a suitable quick shift column against a rigid wall.
Appropriate columns are offered by the diamond tool market.
With the DK42B/52 you can also drill overhead without any further precautions. For protecting the
operator against water, you should however on principal use a water collecting ring (accessory for drill
rig). Consider that the drilled core slips into the core bit and thus loads machine and drill rig additionally.
Bigger cores have to be secured accordingly.
Set the volume of water at the ball valve (1a) such that the carried off material is completely flushed from
the drill hole.
Mud forms round the drill hole points to the use off too less 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 it finally stops.
In this case the segments have to be "sharpened" again by means of a SiC-grindstone.
Take care that the drill bit does not vibrate, otherwise the diamonds are detached by force.
When drilling through reinforcements, you might have to use 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 loosen the drill bit by turning right and left using a suitable wrench. Carefully remove the
machine from the borehole.
DK 42 B DK 42 BL
250 Nm 280 Nm
12
DK 42 BS DK 52
190 Nm 370 Nm
DK 52 S
300 Nm