When I wanted to build my first Hammered Dulcimer I sent to The Smithsonian and asked for free plans. Which they had and sent to me. I heard some place that they would and , as it happened, they did.

Spaw, I built one from Phil Mason's design and while the theory is correct and the measurements where ok it sounded like an exterior door with strings.

Type hammered dulcimer plans into Google and you will find about 30 hits.

Don