In order to fulfill the increasing requirements of modern production machines in terms of precision and quality with optimal resource efficiency, new concepts are needed to reduce the consumption of materials and energy during their manufacture. In this paper, an empirically substantiated strategy for weight and energy reduction in automatic sheet metal bending machines is presented, in which a lightweight design of geometrically complex and mobile machine parts is obtained by means of topology optimization. This strategy was successfully applied to three-dimensional machine frames of the "Lean Panel Bender" machine family of the Salvagnini Maschinenbau GmbH. Compared to older designs, this strategy resulted in large savings in weight, manufacturing and transport costs as well as energy consumption. In this manner, this enables both cost-effective and high-precision production of complexly shaped sheet metal products, both in batch size 1 and in series.