*Corresponding author, e-mail: mustafagoktas@gazi.edu.tr GU J Sci 30(3): 79-88 (2017) Gazi University Journal of Science http://dergipark.gov.tr/gujs Tool Path Generation for Pocket Machining Operations with Island Mustafa GÖKTAŞ 1,* , Abdulmecit GÜLDAŞ 2 , Hakan DİLİPAK 2 1 Gazi University, Technical Science Vocational School, Ankara 2 Gazi University, Technology Faculty, Department of Manufacturing, Ankara, Turkey Article Info Abstract A new method, in which suitable tool paths are generated in order to manufacture pockets in CNC milling machines, was developed in this study. For this purpose, a new algorithm was developed in order to offset pocket profiles with or without the island. In addition, errors that may arise as a result of offsetting were also eliminated. The tool path was generated by using the offset components obtained through this offsetting process. The acquired tool paths were tried after being sent to CNC milling machine. The success of the developed method was proved without any hollow or residue. Received: 13/03/2017 Accepted: 14/05/2017 Keywords Tool path generation, Offsetting, Self-intersection, Pocket milling with island 1. INTRODUCTION One of the most frequently used methods in tool-path generation process is the tool path generation method through repetition of profiles. An accurately-working offsetting method is required for repetition of profiles. According to the literature researches, various studies have been conducted for solving the offsetting problem. Although there have been numerous studies aimed at the offsetting problem, they can generally be collected under a few main titles. The first of them is the method of offsetting process through “voronoi curves”. These curves are used in order to prevent the errors that may arise during the intersection of offset components that are formed in the offsetting process [1-3]. Another commonly used method is the invalid loop elimination method. In this method, closed sub-profiles that form by the offsetting of the closed profile are evaluated independently. These profiles are classified as valid and invalid, and those that are invalid are eliminated. Valid profiles constitute the correct offsetting result. There are various approaches to determine whether the profiles are valid or not. In one of these studies, the profile’s direction was taken as a reference [4]. In another study, the validity of one of the formed profiles was determined through mathematical functions. Afterwards, other profiles were evaluated and their validities were determined according to this profile [5]. In another common method, the circle with a radius that is equal to the offsetting distance is dragged in a tangent line with the profile to be offset. Offsetting result is achieved by using the orbit where the circle’s center moves [5-7]. In the process of offsetting the pocket profiles with islands, the border components that form island profiles are also subject to the same processes together with the components of the main profile. Unlike the main profile components, island profiles are offset outwardly [1, 8-10].