Design of a robotic orbital driller for assembling aircraft structures

Orbital drilling is a machining process designed to drill holes with a double circular motion, added by a linear displacement in the direction of drilling. A cutting tool is rotating at high speed in an eccentric orbit and simultaneously moves towards the surface of the material to be drilled. The adjustable eccentricity plus the diameter of the tool defines the final diameter of the hole. Orbital drilling is a fatigueless process with good surface finish and burr-free when compared with conventional drilling processes. To implement this process, an automatic orbital drilling device has been designed and built as an end-effector of an industrial robot. The process of developing this device, its requirements, functions and tests are detailed in this paper, resulting in the construction of the EFORB (an acronym in Portuguese of Robotic Orbital Drilling End-effector). This paper presents the latest results with the final version of the system, including the development’s integration with an industrial anthropomorphic robot. The results achieved show that the process requirements and tolerances are suitable for aeronautic applications.