Optimal workpiece orientation to reduce the energy consumption of a milling process

Energy consumption in the manufacturing sector is becoming a very hot topic due to its significant ecological relevance, especially for energy intensive processes such as machining. Machining finds nowadays large application mainly due to its high performance, in terms of both surface finish and tolerances achievable; as an example this is the key technology in dies and molds production, largely used in the automotive and housewares sectors. Process optimization could be carried out using different strategies, as already proposed by many authors, such as by optimizing machining parameters or implementing alternative toolpath capable of reducing both machining time and energy consumption. Within this paper will be presented a novel approach that takes into account the product orientation within the working zone of the machine. Milling machines are usually non symmetric regarding the energy consumptions of the axes due to the different masses that have to be moved, hence product orientation could sensibly affect energy consumption in performing a toolpath. Optimizing product orientation has the advantage not to affect product quality and require no adjustment of machining parameters. An approach to model the machine power consumption and to optimize the workpiece orientation is presented together with the results of validation experiments.