Diane Kauffmds wrote:I might be interested in experimenting with this top.
Couple of answers, I made the outer edge thickness (.080) 2mm as original and the inner between brace panels on this version .030 with the "isogrid" panel stiffeners .080 (weigh saving stuff) The braces are .050 thick x .375 high. The board is flexible and weights 400-435 grams. Which will get lighter next version. The board machining starts flat, curls concave when material is removed from the underside, Then I straighten it by hand to get to flat again. The soundboard is installed without a "dome" and when the strings are tensioned, it creates a .100-.080 doming from the string pull.
This versions' thicknesses are a raw guess, and the brace positions are derived from the Geo.Luthier supply drawing. (1914 Martin soundboard) Next version will be lighter
The "Tap Tuning" is a deep gong with long decay duration (i don't know the frequency).
Before the first one was made, the luthier said "it won't work" he was astounded when he first heard it plugged it in. So have other master Luthiers.
The 6061 t6 material Vs wood differential expand/contract question is moot. It provides a stable base for everything else to attach to.
Keep up the questions, I think they keep me motivated.