Cox Violins Blog

Building the Ribcage

Violinmaker-in-Residence #5

Violin ribcage photo array

Left to right: Form with shaped mid-ribs / Mid-ribs attached / Clamping mid-ribs / Shaped ribs / Ribcage attached

Rough blocks spot-glued to form.

Rough blocks spot-glued to form.

The ribs, or sides, of the violin are built around a form-board (link for more on this).  The rough blocks (4 corners and 2 ends) are spot-glued onto the form-board and the shape of the ribcage scribed on them from the template.  The blocks are then carved to shape to receive the mid-ribs, and, after the mid-ribs are in place, carved to receive the upper and lower ribs.

The ribs are 1mm thick pieces of maple, usually similar to the back.  The height of the ribs varies from model to model and has an affect on the air volume of the violin and thus on its tone.  The ribcage can also vary in stiffness through choice of material, thickness, block size, and liner material and dimension, also affecting the sound of the violin.  The ribs are bent to shape on a hot iron and glued to the blocks using hot hide glue.

Liners are added to increase the gluing surface with the plates, and to stiffen the ribs with an “I” beam type of geometry.  Strad consistently used willow for the blocks and liners and that is what is used on the VSO violin.  Spruce or poplar can also be used and have different acoustic properties.

Setting the Liners

Left to right: Ribcage with liners shaped / Liners glued and clamped x 2
Violin back with liners glued x 2 / Violin top with liners glued

The form-board is left in place until the final assembly of the body, when the blocks are freed from the board and the board is removed.

Bending the ribs can be treacherous if the material is deeply flamed such that the grain can run almost cross-ways through the rib. The material for the VSO violin was well behaved and a pleasure to work.

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