Stephen Bannasch (316 ppm)Lots more info here about intonation adjustment after the top is glued to the body: https://learnmaketeachshare.org/making%20instruments/2018/11/20/intonation-for-small-high-performance-guitars.html
Intonation for small high-performance guitars.
I’ve recently finished two small high-performance steel-string guitars inspired by the 1918 Martin 1-18 plans Ted Nelson created for GAL. There are some interesting intonation issues I am investigating that I suspect are inherently more difficult to ameliorate because the tops have been designed to work very efficiently with lightweight steel strings.
At this stage I generated chladni patterns at multiple resonances and took away stiffness in order to make the main lower bout resonance a larger area with smoother borders.
Here’s an example of a Sitka Spruce top fora parlor guitar size at the beginning and end of probably 10 incremental steps carving and sanding away the braces. These steps both reduce weight and make the top less stiff.
See alt text for more info.
