Study of thermostable polyurethane material produced by robotic milling machining

Abstract

The thermostable polyurethane is a material used in the modeling sector and is currently replacing structural parts in control models of the automobile and aeronautics sector, for its ease of machining, in addition to providing good mechanical properties. In this work a robotic machining of a commercial polyurethane material type Necuron® 651 has been experienced. Robotic machining offers a wide possibility of machining and modeling materials with the advantage of increasing the accessibility to pieces, compared to conventional machining centers of three or more axes. Machining has been carried out with a system consisting of a ABB® 6640-235 robot with a Peroni® high speed head and ABB rotary table. The disadvantage of robotic machining, caused by the lack of rigidity of the robot’s morphology, are macro and micro-dimensional errors. Simple geometries with high speed steel tools have been made. The CAM programming has been obtained with the Software Powermill® of the company DELCAM, taking into account two types of strategies for limiting the freedom degree of the robot, to verify geometric results. Finally it has been measured and analyzed the surface generated by interferometer autofocus Alicona and has been measured the geometry of the samples in a coordinate measuring machine (CMM). The results show that both micro and macro errors are significantly reduced by making fixed one of the seven axes of the robotic system.