Three pass incremental sheet forming: a new strategy for the manufacture of brass musical instruments

This paper presents a new three pass forming approach using incremental sheet forming (ISF) for the manufacture of a trumpet bell. Brass musical instruments are traditionally manufactured using artisanal methods (cutting, hammering, spinning and finishing) which are labour intensive but deliver superior quality instruments. The aim of this work was to achieve comparable levels of control using ISF. A series of 20 trials were undertaken to establish optimum set up, forming strategy and tool selection. This has resulted in the three pass approach that delivers consistent wall thicknesses within the tolerance zone and a higher component wall angle (79°) than previously achieved axially in ISF. The resulting components are evaluated using GOM scanning to set out the wall thicknesses and surface finishes achieved, and sets out future avenues for investigation in the forming of brass.