Analysis and Synthesis of Violin Arches

Abstract

Modern methods provide extensive data on the shape of fine old violins.  This should allow makers to copy the arches (for example) of old violins—except that a modern maker would not want to copy exactly the arch of an old instrument.   The arches of old instruments are asymmetrical, and have asymmetrical outlines and bottom edges which are not flat.  The modern maker wants to make a symmetrical arch, with a symmetrical outline, and flat bottom edges.

So the problem is to use the data from an old asymmetrical instrument to somehow construct the arches of a new symmetrical instrument.  In this paper, we describe a construction method that, starting from CT scan data,

• Is strongly based on data from an instrument
• Completely defines the arch from edge to edge
• Involves minimal human choice
• Allows controlled alteration of the arch.

The method produces a 3D model of a violin arch.  The model can be used, for example, to drive a CNC router or 3D printer, to cut cross-section templates ("quinte"), or to be part of modeling the acoustic behavior of an instrument.