In The Thick Of It
Ron
using were flawed-- badly flawed. So eventually I started making
changes on my own; I just about managed to get everything all sussed
out but there's a wee design question that needs to be resolved.
I have a choice between a wide neck or a somewhat scrawny neck-- each
one has their own aesthetic appeal but I worry about structural
failure as the neck must hold up under the strain of nineteen 0.070"
steel strings. If the wood is a good strong wood and the neck suitably
thick-- in this case 1-1/2" thick-- does the actual width of the neck
matter? Will a "thinner" neck hold up as well as a wider neck? Any
help here would be deeply appreciated.
Ron
brian whatcott
bending, and the anti-sway anti-buckle width direction.
Depth is really your friend in resisting bending, which otherwise lets
you lose tune easily. Twice the depth gives four times the resistance.
Thickness needs to prevent buckling sidewards, if you keep the width
at least 1/10 the length, that should not be an issue: a slenderness
ratio of width/length less than 1/20 gets a little more iffy.
Brian W
dlzc
There are two loads you need to consider. The static string load, and
the "plucking" load. Lets say your harp is shaped like a "C". The
strings static load will try to close the "C", and the dimension of
the neck, the side opposite the opening in the "C" (let's call this
inboard), I think you want to call "thickness". In and out of the
screen, I think you want to call width.
Width keeps the strings from folding the harp in "half" by pulling it
into a spiral, and returns the strings to the position that fingers or
picks will need to find them to play notes. 1-1/2" will probably be
OK here, if you stick with wood.
Your first three strings, closest to the opening, when suitably
tightened, will fail your 1-1/2" thick neck, and tightening the
additional strings "inboard" will loosen the outer strings. So I'd
recommend the cross section look something like this:
/|
< | strings-> o o o o o o o
\|
And / or for artistic effect, you may want to stick with a metal
frame, or at least a metal reinforced neck. The sounding box
components are most important, the neck is less so. You can possibly
get less than 1-1.2" thick, and even use hollow members, if you want.
David A. Smith
Ron
dlzc wrote:
> Dear Ron:
>
> On Nov 15, 6:33 am, Ron <r...@dslnorthwest.net> wrote:
> > A while back I started on building a Vulcan harp but
> > the plans I was using were flawed-- badly flawed. So
> > eventually I started making changes on my own; I just
> > about managed to get everything all sussed out but
> > there's a wee design question that needs to be resolved.
> >
> > I have a choice between a wide neck or a somewhat
> > scrawny neck-- each one has their own aesthetic
> > appeal but I worry about structural failure as the neck
> > must hold up under the strain of nineteen 0.070"
> > steel strings. If the wood is a good strong wood and
> > the neck suitably thick-- in this case 1-1/2" thick--
> > does the actual width of the neck matter? Will a
> > "thinner" neck hold up as well as a wider neck? Any
> > help here would be deeply appreciated.
>
> There are two loads you need to consider. The static string load, and
> the "plucking" load. Lets say your harp is shaped like a "C". The
> strings static load will try to close the "C", and the dimension of
> the neck, the side opposite the opening in the "C" (let's call this
> inboard), I think you want to call "thickness". In and out of the
> screen, I think you want to call width.
Hmmm, like Alice, I try to learn six impossible things before
breakfast. <g>
But, you know, I never even thought of the shape which is actually
swan shaped; the three lowest strings are at the base of the neck
while the highest strings go upwards towards the ... "beak"... so to
speak. I always thought the design was quite elegant, but then I
hadn't started building one at the time. :-)
Ron
dlzc
It will be a degree or two easier, if you move the high frequency,
therefore tighter, strings towards the "neck of the swan". (Read
"easier" as lighter, smaller.)
Elegance is to use your voice. Beyond this, is less elegance (or loss
of voice).
David A. Smith
Ron
Thanks for the tip David but I don't know if it's applicable here;
unlike with traditional designs, instead of using strings that go up/
down in thickness for the various notes, this harp just uses one size
[electric guitar] string only. But I was thinking about using standard
harp strings, and I may try them some day... :-)
> Elegance is to use your voice. Beyond this, is less elegance (or loss
> of voice).
Lol, people tell me that my voice is anything *but* elegant and I
should stay far away from any American Idol auditions. <g> However as
for the harp, designer Wah Chang was a creative genius-- doing makeup
and designing a variety of gizmos to be used as props for movies as
well as TV shows like Star Trek, the Outer Limits, et al. I think his
harp design was his best work:
http://www.maidenwine.com/08_discography/startrek/twte_08.jpg
but too few people appreciate it the way I do. Pity... :-)
Ron
------------------
"In the beginning was the rhythm; but I had forgotten and I was
waiting for the word."
-- Ray Manzarek --
>
> David A. Smith
dlzc
On Nov 16, 7:20 pm, Ron <r...@dslnorthwest.net> wrote:
...
> Thanks for the tip David but I don't know if it's
> applicable here;
It absolutely is.
> unlike with traditional designs, instead of using
> strings that go up/ down in thickness for the
> various notes, this harp just uses one size
> [electric guitar] string only.
A lot of older instruments use a single "grade" of string.
> But I was thinking about using standard
> harp strings, and I may try them some day... :-)
The frequency goes up with tension (for a fixed length). Putting
higher tension wires further from the "neck", stresses the neck more,
than if they were closer.
Its your free time...
David A. Smith
Ron
Well, as Admiral Kirk once said "We learn by doing..."
Ron