Reducing Build Variation in Arched Guitar Plates

Abstract

The objective of volume production is to produce identical products with little to no build variation in their parts. However, in instrument manufacture, this can be a challenging task due to the natural variation in wood properties. The purpose of this paper is to illustrate an approach to reduce build variation in the production of arched plates for acoustic guitars by using CAD/CAM software and the CNC machine. To accurately machine the arched plates, a family of curves called curtate cycloids was used during the design phase. The paper will also discuss the effort to reduce build variation during the manufacturing process by placing the arched plates under load while being machined. A series of arched back plates has been produced using this approach, and the build variation, as measured by resonant frequency, is notably reduced.