Thin Wall Manufacturing Improvement using Novel Simultaneous Double-Sided Cutter Milling Technique

Abstract

Thin-walled parts are commonly used in the aerospace sector. However, there are serious machining challenges, such as deflection, deformation and vibration. The final thin-walled component machining will deteriorate the dimensional accuracy and surface quality. This is due to the vibration and deformation that occurs during flexible milling of thin-walled structures since the workpiece rigidity is lower than the cutting forces of the milling cutter. The gradual reduction of the thin-wall thickness during the end milling process results in significant deflections and deformations due to its low rigidity and low stiffness. In recent years, different approaches have been used to deal with these challenges. This paper presents a new technique for machining thin-walled parts with great accuracy, excellent flatness and straightness properties, and good productivity. The authors have developed a new milling technique using simultaneous double-sided cutter milling, in which synchronized vertical double end milling cutter finishes and machines both thin-wall surfaces simultaneously. This produces lower cutting thrust forces on the walls, as each cutting thrust force cancels out the other. The rotation of the milling machine spindle is transmitted to the double cutters by an in-house double-axis adapter. Surface errors are minimized, flatness and straightness properties are significantly improved, and the thin-wall deflection can be neglected, as shown in our results. The thin wall can be finished in only one pass, and a 50% reduction in machining time can be achieved. In addition, thin-wall flatness is improved about two to three times, compared to the conventional milling procedure.