Too Much Strain On My Neck?

The formula for deflection with normal force at the end of a cantilever is well known. If a string is stretched from the end to a bridge at some angle to the end then Tension sin (string angle) gives that normal force. Tension X cos(string angle) gives the compression in the cantilever - not usually an issue....

Is that enough to go on?

Brian W

That isn't really the issue your guitar maker friend was raising. And one can only guess what you might do with the information if you did know the answer to your question. The issue is that wood will split fairly easy in one direction. the difference in tensile strength depending on direction for wood can be enormous. What your friend is probably trying to tell is that by making it from one piece of wood there is no way to arrange the grain of the wood so that it won't be extremely weak at some point and when you tighten the strings it will just split along the grain.

-jim

Ho hum, I finally took the precaution of looking up an image of a Vulcan harp, and I see that the neck axis is side-offset to the strings' direction. This means that the normal load due the bridge offset is small in comparison to the normal load due to the strings' angular offset. This puts a twist into the neck..

It may be worth saying that the main spar of light aircraft with wood wings can be a hollow box, or sometimes, a single solid timber of spruce.

Brian W

Mr. Spock would probably say that there always possibilities-- but in this case there aren't that many options, construction-wise.

Ron

Dear Ron:

If you form up a composite structure, laminating layers of wood with intelligently-placed grains, I suspect you can make it work. But tuning it would be a nightmare.

The Greek's had an "open-sided harp", if you want to do a Google search for it.

David A. Smith

Thanks for the suggestion David, I'll look into it. But I always thought that the cantilever principle was a way to get strength where it might not be otherwise?

Ron

Dear Ron:

Strength =/= stiffness. Stiffness retains tune.

David A. Smith

Than I better use some high quality wood. Happy Holidays! :-)

Ron