‘BBT’ Acoustic Guitar Kit Tooling & Alternate Top Bracing Development

Shepherding inexperienced students as they build playable, customized acoustic guitars is often daunting; STEM faculty may help meet challenges with access to appropriate tooling and following best practices. The ETSU Guitar Building program has developed, tested, and refined numerous molds, dishes, templates, jigs, gages, & fixtures and top bracing patterns for use with the STEM Guitar Project’s (BBT) Acoustic Guitar kit to ensure that engineering technology and bluegrass students will be able to build ‘performance quality’ instruments of desired tone and voicing. Significant effort was made to create accurate yet inexpensive designs that can be easily shared digitally for production by facilities with access to CNC routers and/or CO2 laser cutter/engravers.

Part I of the presentation will be an overview of the infrastructure, tooling, typical uses, and some best practices. Topics will include BBT-specific (a) side mold assembly; (b) radiused workboards & dishes, (c) go bar deck, (d) orientation, positioning, layout, & marking templates; (e) jigs to ensure proper alignment during gluing and installation; (f) a modular lofting gage set for customizing variable neck contours; and (g) binding bending fixtures.

Part II will highlight alternate top bracing designs developed & prototyped to provide students with tonal options to the traditional Martin-style X-braced guitar. Alternative designs based upon Doug Hunt’s innovative ‘tab and slot’ design will be presented: a vintage ‘ladder’-style bracing layout, a hybrid ‘X-braced fan’ bracing layout in the style of European or classical instruments, and early effort in a laminated curve or ‘falcate’ style of bracing.