Acoustic guitar building is an exercise in balance. On one hand you have to consider that you are creating a tool for the making of music, it has to be sturdy, able to take a certain amount of abuse, the small nocks and nicks that even the best cared for instruments are subject to. Couple that with the fact that ever stringed instrument has to contend with the cumulative compression from the pull of the strings, and the changes in humidity that can cause expansion and contraction. So strength or the ability of the instrument to resist these forces has to be in the mind of anyone who is going to build successful guitars.
If strength were the only concern then, guitars would be constructed like kitchen cabinets! Obviously this approach would not produce the kind of sounds we have come to expect from a well built instrument. So the counter balance to strength has to be the weight of the plates ( top and back ) braces , sides and the other components that make up the whole.
So the true balancing act is to come up with a design that is strong where it is important and light where it needs to be. In the first photo you see a view of the completed rim of my HJ45 the U shaped block is an idea that came from renown builder Charles Fox and is referred to as a faux Spanish heel. This block strengthens a traditional weak area of the guitar. As I’ve seen many times in my role as repair guy there is a very common problem with many guitars of all makes to develop a hump in the fingerboard where it goes over the body , the reason for this is simple, necks are linearly stiff , but the area above the sound hole is comparatively weak thus the possibility of the hump. With the faux Spanish heel, this potential headache is all but eliminated.
Photo two shows the completed body with neck . As you can see the tongue of the fingerboard is supported by the neck extension. Additionally the neck has two imbedded carbon fiber rods that run the length of the neck and extension making it a complete unit.