11
GB
7) SAFETY CLUTCH
This machine is equipped with a mechanical clutch to protect the operator and machine from excessive
torque forces. When the preset maximum torque level is reached, the clutch will slip.
After the clutch slips many times, it will become worn and slip at lower and lower torque levels.
When this happens, it must be serviced by an authorized service provider.
The recommended torque of the clutch nut is 21 Nm.
CAUTION: Always ease off the load immediately whenever the clutch slips. Do not allow the clutch to
continue slipping or it will wear out prematurely.
DRILLING INSTRUCTIONS
1.
Press the “Reset” button on the PRCD interrupter device to energize the circuit to the machine. Then turn
the machine on.
2.
Open the water valve slightly and very gently begin the cut. use very light feed pressure to prevent the
bit from wandering until the bit is fully penetrated into the cut.
3.
Make adjustments to the water feed as needed. The water leaving the cut should be a solid colored
slurry with about the consistency of milk.
4.
Once in the cut, use steady feed pressure .
5.
When the bit is about to break through, reduce feed pressure .
WARNING: Always keep your face away from the machine.
ABOUT DIAMOND BITS
The diamond impregnated segments in a wet type (sintered) diamond core bit operate on a principle of
controlled erosion. The bond matrix holding the diamonds is continually worn away by abrasion with the
work piece, exposing the harder diamonds to stand proud from the bond matrix. Without adequate
water, the bit would overheat and be destroyed.
With too much water and not enough feed pressure, there would not be adequate erosion of the bond
matrix and the bit becomes dull. This is called glazing . If the bit seems to refuse to cut anymore, it is
glazed.
See below: ”SHARPENING A GLAZED BIT ”
Don’t feed too gently or the diamond segments will become glazed. Keep the bit steadily working. If the
cut is very deep, the core plug may be obstructing the flow of cooling water. In this case, stop drilling, and
chisel out the core plug before continuing.
CAUTION: If the bit gets stuck, do not try to rock it loose by turning the switch on and off. That is
hazardous and could damage the motor. Rather, unplug the machine and use a wrench on the bit
mounting to work it loose.
If embedded steel such as rebar is encountered take special care. Reduce the feed pressure by about 1/3
and let the bit go at its own pace, if there is too much vibration the bit will be destroyed.
Once the steel is passed, continue normally.
Summary of Contents for DM10
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