Turn the throttle lever gradually and drill at a slow speed until the hole is collared. The drill should be kept at right angles to the work until the hole is collared, then repositioned for angle drilling. Always apply sufficient down pressure to keep the tool from bouncing.
[pdf] Visit the official website of the rock drill manufacturer. Use the search function to find your specific model number. Look for a section on “spare parts” or “accessories.” You should be able to find a list of compatible parts for your model.
[pdf] A slender oil pipe with many elbows and not fixed could cause the pipe to shake when the oil flow rate is high. An unbalanced rotating part of the motor and hydraulic pump, poor alignment during installation, or loose coupling can generate vibration and noise.
[pdf] 
