aluminium. Since the parts are stressed mainly by bending torque, a truss structure, where most of the material is placed as far away form the middle axis as possible, was used to guarantee a high flexural stiffness and a low mass at the same time. The lateral arms were welded using normal 20 mm x 20 mm rectangular aluminium profiles with a wall thickness of 2 mm. Aluminium was chosen because of its low density at comparatively high strength and the low risk of corrosion. All parts add up to an aggregate mass of 6.7 kg, which represents about 11% of the total mass.
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