Virtual compensation of deflection errors in ball end milling of flexible blades

The deflections of highly flexible turbine blades and slender end mills lead to tolerance violations during milling. This paper presents a digital simulation and compensation model for blade machining operations. Stiffness of the blade at the cutting zone is updated as the metal is removed without re-meshing using a computationally efficient sub-structuring technique. The cutter-workpiece engagement is evaluated by considering the deformations of both end mill and the blade under the cutting loads. The estimated deformations are compensated by modifying the tool path coordinates. The model has been experimentally verified in ball-end milling of a blade whose dimensional errors have been reduced from ∼70 μm to ∼10 μm.