In my absence at the dacha, my wife fastened brackets for profiles (which are under drywall) with a 6mm drill for concrete. Shurik coped with such work effortlessly, but after a couple of not very intensive days of work, the gearbox began to throw off the puncher mode on its own, and the cartridge jammed. And oil leaked from the gearbox. It was impossible to get the drill (it clamps the cartridge perfectly - this is probably an advantage). I had to take it to the official service (it is one trip in Hong Kong), since it was repaired there. and in a couple of days. But they flatly refused to say what exactly was broken! they did not even give any conclusion or a list of the work done. Impressions are ambivalent so far. Further operation will show. (ated. few months after repair. normal flight)