FAQs - Frequently asked questions 

General questions:
	Drilling rate suddenly slows down
	Abrupt slowing-down while drilling, although previously good drilling rate
	When drilling, the core grinds against the wall on one side
	Water or air extraction fails
	Enlarging existing bore holes
	Broken segment
	Using the vacuum system
Questions on the theme of dry drilling:
	Drill core cannot be removed when dry drilling
Questions on the theme of wet drilling:
	Drilling rate suddenly slows down when wet drilling,Waste water very clean - hardly cloudy at all
	Drill core cannot be removed when wet drilling
Drilling rate suddenly slows down
Core cutter could have become blunt. To wear down the bond and release new diamonds, the application must not be too hard. When drilling hard, smooth materials, it can occur that the segments do not re-sharpen sufficiently. In this case, short drilling in breeze block, soft limestone, sharpening stone (or other abrasive materials) can be carried out to re-sharpen. Re-sharpening should be done at low speed. A few seconds or a few turns are sufficient. The water supply can be cut off for a short time for re-sharpening. This makes re-sharpening more efficient. The core cutter can also be sharpened by holding the face of the segments (take core cutter out of drilling system) on a grinding disc or a grinding block. Note: if this recurs; it usually means that an incorrect core is being used for the application. The drill stand is probably not fixed correctly. Slight changes in the position of the drill stand can lead to the core cutter jamming during drilling. This jamming forces the core cutter to slow down and considerably reduces the drilling rate.
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Abrupt slowing-down while drilling, although previously good drilling rate
The drill core may be broken, the loose core slows down due to contact with the material that is being drilled into causing friction.
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When drilling, the core grinds against the wall on one side
Ensure that the entire drilling system has a firm hold on the wall. Readjust the drilling system if necessary.
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Water or air extraction fails
Abort the drilling procedure immediately because otherwise this could cause overheating and loss of stability of the diamonds (as of approx. 800 °C). Check the water supply line, increase the water pressure if necessary. Flow indicator must turn steadily. Rule of thumb for the right water quantity: waste water should be coloured grey from the drilling sludge. If the waste water is clear, it is possible that too much water is being supplied (unnecessary water consumption). Clean the dust extraction filter or empty the dust collector when dry drilling (use a more powerful device if necessary). The opening in the bottom of the core cutter can become blocked with drilling dust deposits. Remove deposits with a rod.
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Enlarging existing bore holes
Fill the first bore hole, so that coolant is definitely fed to the segment at the core wall and does not flow out through the existing hole. Significantly increase the water supply when drilling into a hole. The same applies for air-cooling when dry drilling.
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Broken segment
If the segments hit loose, movable reinforcement parts, these parts can suddenly get between the segments, causing them to break off (only cut through loose iron reinforcements with extreme caution at low advance rate). In this case, do not continue drilling, instead take the loose segment out of the bore hole with a hook-shaped curved welding rod, for example, and have the core cutter repaired. Otherwise the other segments will also break off.
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Using the vacuum system
The stand sticks firmly to the wall by means of a vacuum. The fixing method is only as good as its surface! Applications such as badly pasted tiles may not be able to withstand the force of the stand. The same applies to walls in lightweight construction (plaster walls, elements, covered wooden walls, etc).
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Drill core cannot be removed when dry drilling
In general, first knock out the drilling dust after drilling, hold the core cutter with the opening at the bottom and tap it lightly with a piece of wood, then push the drill core out through the shank with a rod. Slanted cutting through wall joints can cause pieces of the wall to become wedged in the core cutter. In this case, knock out the drilling dust and loosen the wedged pieces by shaking the pipe or moving it back and forth and push the core out with a rod.
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Drilling rate slows down suddenly when wet drilling, Waste water very clean, hardly cloudy at all
If very hard inlay or reinforcement is hit, increase the feed pressure slightly. Vary the feed pressure if necessary (light pumping). Reduce the speed if necessary, until the reinforcement has been drilled through. A piece of reinforcement has possibly come loose and become jammed or stuck in the segments of the core cutter. In this case, remove the core cutter and remove the loose piece of reinforcement manually.
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Drill core cannot be removed when wet drilling
In general, do not cut off the water directly after drilling, instead leave it running for a short while in order to rinse out drilling sludge between the core cutter wall and the drill core. If necessary, loosen the jammed drill core by lightly tapping the core cutter. Do not strike the pipe with hard objects. This presents a risk of deforming the pipe because the pipe walls are sometimes only 1.5 mm thick. Tapping lightly with a piece of soft wood or plastic achieves the same effect.
If necessary, push the drill core out through the shank with a rod. When starting to cut reinforcements in the outer area of the drill core, wedge-shaped pieces of reinforcement can come loose from the drill core. These pieces of reinforcement can lead to the drill core becoming wedged in the core cutter. In this case, rinse out the drilling sludge and loosen the wedged pieces by shaking the pipe or moving it back and forth and push the core out with a rod.
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