AGP DM5 Manual De Instrucciones página 9

approaching at an angle of about 30 degrees to the cutting surface. (A large piece of wood with a large V
notch cut in it will help prevent the bit from wandering at the beginning.) Once about a third of the arc is
cut, straighten the bit to the correct perpendicular angle while keeping enough feed pressure on the bit
to prevent it from wandering.
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 breaking through, hold the machine tightly and reduce feed pressure .
WARNING: Always keep your face away from the machine.
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 holding by hand, take great care to keep the bit aligned to the hole. If the bit is crooked, it will easily bind.
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.
CAUTION: Drilling operations are very stressful to the motor and at the end of the cut, the motor
temperature will be very hot, always run the motor at no load for a few minutes until the temperature
returns to a normal range before shutting off.
RESHARPENING A GLAZED BIT
If the bit becomes glazed, resharpen by dressing with an appropriate alumina oxide or silicon carbide dressing
stone. Simply drill into the stone as many times as necessary to restore its cutting performance.
VIBRATION TROUBLESHOOTING
If vibration occurs and it is not caused by embedded steel, stop drilling to find the cause and remedy.
CAUTION: Do not operate with vibration or there will be serious hazard and the diamond core bit
will surely be destroyed.
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