1,dia of drill head is increased, 2,the derrick,self-traction device are ... developed on XY-4 -3drill. The central opening dia of drill head is increased, and we add a derrick, a self-traction ... core drilling, but also in engineering geological. If the drill is equipped with a 22 kW of 30 kW, 6 ... m)200-400, 50-100, 25-50Hole dip angle (°):360Swivel Head (when power speed is 1500 r/min)Spindle speed (r ...