X bracing angle
Benoīt Meulle-Stef
particulary 90°. I used 90 on one guitar I did but looking at the Ds OM and
OOO guitars I realized they all have a different angle... Anyone have
noticed a different in tone with angle change? Or the angle in only they to
acomodate bracing depending on the space between the bridge and the
soundhole?
Cheers
Ben
alcarruth
lengthwise and crosswise directions needs to be 'balanced' in some
sense for it to work right, then the function of the X brace angle
becomes obvious. If the top is particularly 'floppy' in the croswise
direction, or the body is relatively wide, then you might want to run
the bracing a little more across the grain.
Of course, the main job of the bracing is to resist bridge torque, so
you don't want to flatten the brace angle too far. Small changes can
make a difference, though.
Alan Carruth / Luthier
Kevin Hall
In general terms the tighter the X the brighter the tone, and the more open
the angle the bassier it sounds. Of course other considerations like the
distance from the crotch of the X to the soundhole, relative distance from
the bridge, size and weight of braces etc. have their own effect on
performance, but you'll find the above rule of thumb pretty decent.
Another consideration is the half-lap joint of the X itself. Most
factories contour the braces before they're fitted to each other at the
crotch, which means that the rounding of the top surface of the brace
reduces the contact area of the two sticks in the traditional half-lap
joint. Many hand builders, including this one, prefer to glue their
braces down prior to contouring their tops. That means you can leave the
braces at full height and in full contact where they join, and round the
tops of the braces off from their outward. Makes a much neater looking
joint, and probably noticeably stronger as well.
Manufacturers usually conceal the gaps in the pre-contoured joint by soaking
a cloth .22 calibre firearms cleaning patch in white glue, then slapping
that over the joint as a reinforcement.
KH
"Benoît Meulle-Stef" <bmsguita...@biz.tiscali.be> wrote in message
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Benoīt Meulle-Stef
blueprint! Mike doolin uses a bar just under the bridge plate to prevent
warpping, taht could be a great idea with wide angle and many strings....
Cheers
Ben
"alcarruth" <alca...@aol.com> a écrit dans le message de news:
1152120200.4...@l70g2000cwa.googlegroups.com...
Clifford Heath
I saw that Cole Clark have some guitars using it. It looked
pretty good to me, but I didn't play or listen to one of the
instruments.
Kevin Hall
amazing load of promotional cobblers ever heard by mortal man. According
to the factory rep at the Canadian trade show ( MIAC) of 1971, Gibson
employees had 'discovered' the recipe for the new bracing in Orville
Gibsons' old travel trunk, and the factory immediately put it into
production.
Given that the link between the Gibson guitar company and Orville Gibson was
tenuous at best, that's a highly unlikely bit of fiction.
The idea of their design was to brace the top rigidly enough to allow the
use of very thin and flabby spruce plates. It didn't work. The incidence
of failure in those models was incredible, and the sound of the majority
which survived past the first 2 or 3 years was awful.
The system creates a 'diamond' of bracing around the bridgeplate, and that
makes it virtually impossible to replace a cracked or warped plate without
doing serious damage to the top and the techs' arm. Overall dimensions of
the bracing were too large and the brace stock itself was usually very poor
in quality. Bridgeplates were thick, sometimes plywood, and the
workmanship was dreadful.
It may be possible to use a similar design to produce a decent sound and
acceptable reliability, as long as the luthier used some sense in the
selection and dimensioning of materials, but I doubt such an excercise
would be worth the time and effort.
By 1974, top failures on the double X models were so numerous that Gibsons'
Canadian warranty centre, 'Len Davies' in Scarborough was buried in them.
The chap who ran the place at the time was Jerome Kern ( not that one), and
he enlisted the aid of the shop in which I had an interest then; Ring Music
in Toronto. They supplied us with stacks of new replacement double-X tops,
and for a while we were re-topping a couple a week for them in between our
'real' work.
To be fair, the tops were not the only problems with those guitars, but
they were the major irritant. Laminated rims and backs on some models
didn't help, nor did back bracing which looked like wall studding for an
outhouse.
KH
"Clifford Heath" <no....@please.net> wrote in message
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Benoīt Meulle-Stef
bridge plate looks more like a piece of furniture... Amazing piece of
junk...
Ben
"Kevin Hall" <timbe...@webhart.net> a écrit dans le message de news:
12aq7vg...@corp.supernews.com...
alcarruth
spoken with some Gibson folks after the double-X was taken off the
market. They told him that when the line was dismantled, somebody
checked the setting on the top sander, and found that it was putting
out tops .090" thick. The blueprints called for .120". That alone would
reduce the stiffness of the top by about 30%.
A few years ago I decided to check out how double-X bracing would work
when properly done. I built a matched pair of small Jumbo guitars, with
that as the major difference. I took them to the ASIA Symposium and
passed them around, without telling anybody in advance what the
difference was. The playing/listening tests were conducted partly in
the exhibition area, which was noisy, and partly in the lobby, which
was more like a living room setting. In the end, the preference was for
the double X top, by a margin of about 2:1, with the preference being
more pronounced in the quieter setting. The two guitars don't sound a
lot different, but the difference is clear.
One very fine builder, toward the end of the testing, spent some time
getting the two accurately in tune, without playing them much. She then
played three selections on each one; in flattpick, fingerstyle, and
jazz idioms. At the end she expressed a prefference for the double-X,
and asked what the difference was. When I told her, she exclaimed: "But
that doesn't WORK!". ;o)
I wrote up the experiment, and it's been published in 'Guitarmaker'
magazine.
Alan Carruth / Luthier
Benoīt Meulle-Stef
Ben
PS: Ther are a couple of folks who built guitars with double X nowdays.
"alcarruth" <alca...@aol.com> a écrit dans le message de news:
1152210583.8...@k73g2000cwa.googlegroups.com...
Kevin Hall
sander was an error. I can distinctly remember the Gibson reps droning on
at the ' 71 show about how the new bracing was designed to allow them to use
much thinner and more flexible tops. They used it as part of their sales
spiel, and the difference in thickness was obvious. On many of those
guitars you can see the bracing right through the top while they're hanging
on the shop wall.
I would suspect that Mr. Umanov was the victim of yet another attempt by
someone at Gibson to explain the unexplainable. Even at Gibson someone
somewhere along the line would notice a .030" discrepancy in top thickness
if it been done accidentally.
KH
"alcarruth" <alca...@aol.com> wrote in message
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Clifford Heath
> Gibson introduced 'double X' bracing around 1970,...
Thanks all for your thoughts. I did some more googling, and
realised that what's known as double-X bracing isn't at all
what I saw at Cole Clark. The Gibson double-X puts an X
crossing between the bridge and the sound-hole, and another
X behind the bridge to cross half-way to the end block.
Cole Clark have a top that has two tall narrow X's, one each
side of the bridge plate, running the full length of both bouts.
There was some cross-bracing as well, I guess it ran under the
two X's. All their bracing drops into CNC'd channels in the top
wood itself, for a kind of kerfing effect.
Anyhow, has anyone seen this pattern elsewhere or have a comment
on it?
Clifford Heath.
Mattia Valente
The Cole Clark guitars have a pretty unique bracing setup. One of the
mags (either ASIA's or GAL's, can't recall) ran a feature on them a few
months ago...
Mattia
alcarruth
Kevin Hall wrote:
<< I would suspect that Mr. Umanov was the victim of yet another
attempt by
someone at Gibson to explain the unexplainable. Even at Gibson
someone
somewhere along the line would notice a .030" discrepancy in top
thickness
if it been done accidentally.>>
Hard to say: they've passed some pretty amazing stuff, so I wouldn't be
surprised either way. I've read that the philosophy at Gibson is that
the onlt person on theline who has to knopw anything about guitars is
the guy who sets it up. They're trying to get away with using
semi-skilled labor, and that's the sort of thing that happens.
When the Gibson 'Mark' series first came out I stepped into a local
music store, and one of the employees pulled me aside to show me one
that had just come in. You could see the brace pattern on the outside
of the top: the finish had turned dark owing to migration of solvents
from the hot melt glue they used. With siuch a complicated brace
pattern they had to do something to speed up production, but nobody
thought to check and see what unexpected effects might come up. That's
the problem in a nutshell.
Alan Carruth / Luthier
Kevin Hall
That Mark series was an even bigger disaster than the double x stuff. At
the time, some of those things which had been meant to retail for around
$2k were being pushed out to employees as 'thirds' for $80. Awful design
and even worse execution.
My point on the double X jobs was that if the skinny tops had been a product
of an error in set-up which was discovered only when they shut the line
down, the sales reps wouldn't have been trumpetting the thin lids as a
virtue back when they first went into production. The reps from Kalamazoo
who were at the ' 71 MIAC show in Toronto were definitely claiming the thin
tops were intentional, made possible by the cunning new bracing design.
Old time repairmen who visited the booth and heard that pitch were warning
other potential victims not to step in any marketing on their way through.
KH
"alcarruth" <alca...@aol.com> wrote in message
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Benoīt Meulle-Stef
putted the most amazing bridge thickness. Frank Ford told me they have about
7 bidge mesures to be shure to have one who will almost fit. Or they sand
the body to change the neck angle (a lot of them have a very thin binding
near the neck jonction...)... When I take a look at my Style U harp guitar
from 1908 I cant believe it came from the same maker...
Ben
"alcarruth" <alca...@aol.com> a écrit dans le message de news:
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