Design of a fixture to balance helicopter rotor blades
Parellada Roura, Manel
This report describes the design project presented by Advanced Composite Structures (ACS) regarding the balancing of helicopter rotor blades after repair and the design was recommended for performing the balancing procedure. The final recommendation was comprised of three separate designs, each for a different blade length. The team recommends ACS continues using the current setup for the small and medium sized blades, but recommends a new design for weighing of larger and heavier blades. The recommended final design makes use of the same parts as used for medium blades and therefore requires no retraining of personnel to assemble. The final design consists of a box-shaped frame which rests on three scales. Different scales are recommended for use with the final design in order to increase the maximum weight of blades able to be balanced. The tip rests on two scales to allow for chord-wise and span-wise balancing while a third scale at the root end of the blade allows for calculation of the total weight of the repaired blade. In the design, criss-crossing cables are used to eliminate error caused by lateral forces applied to the fixture when the helicopter blades are placed on it. Cables running below the fixture allow for deflection caused by the weight of the blade to be negated. The final design meets all the criteria were provided by ACS other than maintaining the same level of accuracy in the scale readings. The team feels this was the best option as it increases capacity but still takes into consideration the budget limitation.
fixture, balance, helicopter, rotor, blades