Original Article A discrete simulation-based algorithm for the technological investigation of 2.5D milling operations Adam Jacso 1 , Tibor Szalay 1 , Juan Carlos Jauregui 2 and Juvenal Rodriguez Resendiz 2 Abstract Many applications are available for the syntactic and semantic verification of NC milling tool paths in simulation envir- onments. However, these solutions – similar to the conventional tool path generation methods – are generally based on geometric considerations, and for that reason they cannot address varying cutting conditions. This paper introduces a new application of a simulation algorithm that is capable of producing all the necessary geometric information about the machining process in question for the purpose of further technological analysis. For performing such an analysis, an image space-based NC simulation algorithm is recommended, since in the case of complex tool paths it is impossible to provide an analytical description of the process of material removal. The information obtained from the simulation can be used not only for simple analyses, but also for optimisation purposes with a view to increasing machining efficiency. Keywords 2.5D milling, tool path, material removal simulation, material removal rate, cutter engagement Date received: 17 August 2017; accepted: 10 January 2018 Introduction Many applications are available for the investigation and control of milling tool paths in simulation envir- onments. The syntactic and semantic verification of NC programs can easily be executed with the help of virtual CNC controller software applications on PCs, or even with the help of real CNC controllers using the test mode. Nonetheless, these solutions are similar to the conventional tool path generation meth- ods, which, as a rule, are based on geometric consid- erations, and they are not able to address varying cutting conditions. 1 Even in the case of NC programs, which are produced with the help of CAM software, little is known about the cutting process that takes place during machining. In fact, the above-mentioned applications allow only for geometrical investigations: with their help, it can be verified if any uncut regions remain, if any collisions occur, etc., but the material removal process itself remains undiscovered. This paper introduces a novel technological analysis that specifically focuses on the material removal process. Before presenting the algorithm itself, we wish to jus- tify why technological analysis is necessary. The importance of cutting process analysis One of the needs for these analyses is in rough milling. Rough milling operations are generally produced by way of 2.5D milling, in which case machining is car- ried out on X–Y plane and the movements along Z- axis are used exclusively for positioning the tool in accordance with the cutting depth. In that case, the task of tool path generation can be considered as a planar problem. As a result of this, it is quite easy to plan a geometrically correct tool path where the com- plete removal of allowance formation is carried out. However, the situation is actually more complicated from a quality point of view. 2 1 Department of Manufacturing Sciences and Engineering, Budapest University of Technology and Economics, Budapest, Hungary 2 Faculty of Engineering, Autonomous University of Queretaro, Queretaro, Mexico Corresponding author: Adam Jacso, Department of Manufacturing Sciences and Engineering, Budapest University of Technology and Economics, Budapest, Muegyetem rkp. 3, Hungary. Email: jacso@manuf.bme.hu Proc IMechE Part C: J Mechanical Engineering Science 0(0) 1–13 ! IMechE 2018 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0954406218757267 journals.sagepub.com/home/pic