An advanced balancing methodology for the propeller of a wind-tunnel model

\The focus of this paper is a versatile balancing procedure, developed to compensate for the asymmetries of a propeller blade's settable angle, in the range -5 to +35. The standard balancing procedure (ISO 1940-1) was found to be inconsistent with the required quality grade, so a new balancing technique was created. A case study of propeller unbalance revealed a set of important details that must be uniquely assessed for such a complex balancing task. For the existing ISO notes, most of these details are descriptive rather than comprehensive. The new balancing concept defines the following: acceptable tolerances (shape, run-out and roughness), balancing order and priorities, a lower margin of residual unbalance, balancing accessories and regimes, unbalance correction and the verification of the results. (C) 2007 Journal of Mechanical Engineering. All rights reserved.