A drilling apparatus for drilling from inside a conduit having at least one service entrance is described. The drilling apparatus comprises a robot; an elongated flexible appliance having a first end and a second end, the elongated flexible appliance connected to the robot; a rotatable drill head connected to the second end of the elongated flexible appliance; the elongated flexible appliance driven by the robot to extend the rotatable drill head inside the service entrance by at least 8 cm and to retract the rotatable drill head out of the at least one service entrance. The apparatus further comprises means to bend the elongated flexible appliance to orient the drill head connected thereto perpendicular to a longitudinal axis of the conduit.