BRACING / STRUT PATTERNS (Full Version)

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JBASHORUN -> BRACING / STRUT PATTERNS (Dec. 31 2005 17:08:15)

Hola,
I'm in the process of making my first guitar. It is sort of going to be a blanca. But with maple instead of cypress, as the cypress was not available.
I have made the body slightly shallower than recommended for a classical guitar by about 5mm. I have also made the soundboard about 2.6-2.7mm thick.
Now comes the bracing. We were only taught one method of bracing for classical guitars. I think its a torres style layout with fan struts, 2 harmonic bars (upper and lower), 2 angled struts between the harmonic bars, and a soundhole patch.
But as far as I know this is a standard classical strut pattern. I would like to know if there are many variations of strut patterns, and in particular for flamenco guitars. If so, which is best? I would ideally like to create a bright sound with more treble and much less bass.
I know there is some degree of "secrecy" around each luthier's special techniques to make their guitars sound better. But if anyone can help me out it would be appreciated. or even recommend a website listing specific bracing patterns just for Flamenco guitars.

Thanks,


James




Skai -> RE: BRACING / STRUT PATTERNS (Jan. 2 2006 5:01:29)

Hi James,

Just a thought. I don't really think that bracing designs are all that secret anymore. Just look inside through a dentist's mirror! [:D] Sure the finer details aren't visible but the rough bracing patterns should be found quite easily.

Good luck with your first guitar, it's always better to experiment with cheaper woods. Hope you can make me a handmade flamenco later on.

Cheers,
Cheston




JBASHORUN -> RE: BRACING / STRUT PATTERNS (Jan. 2 2006 14:22:45)

Cheston, thanks for the advice. I think I'll check out the bracing patterns in all my guitars at home. But the problem is that I only own one Flamenco guitar, and thats my Yamaha. I can check the inside of the Yamaha and see what the strutting is like, but as I might have mentioned, the Yamaha doesn't particularly have a good Flamenco tone.
I would be more interested to see the inside of a better guitar. for example, one of Anders' blancas. Simon says that Anders' guitars are "the brightest he has ever tried" and I would be keen to know what his secret is and exactly how he does it.
For example, Anders once mentioned that he only uses ONE harmonic bar. whereas my guitar has TWO. Its small details like this that make a lot of difference to the sound of a guitar. And that can make the difference between a good guitar and a bad one.



James




Skai -> RE: BRACING / STRUT PATTERNS (Jan. 2 2006 22:21:38)

Ahh.. Now that's a secret! [:D]




JBASHORUN -> RE: BRACING / STRUT PATTERNS (Jan. 2 2006 22:44:31)

11.21pm?!!!

Cheston, you're up very late aren't you? Or maybe early? Isn't it like 6am over there? You must be getting ready for work?


James




Armando -> RE: BRACING / STRUT PATTERNS (Jan. 3 2006 15:33:20)

quote:

I would like to know if there are many variations of strut patterns, and in particular for flamenco guitars. If so, which is best?


Hi JBASHORUN

Welcome in the club. I have recently finished my second flamenca blanca as well. Pictures and videoclips will be availlable soon on my website.

Let me give you some comments.

The seven fan bracing pattern with the two lateral closing braces as by Torres is in fact the standard pattern applied on guitars built in the traditional spanish style. I wouldn't say that this pattern is only suitable for classical guitars. The top sevillan Luthier Francisco Barba uses a similiar pattern for his flamenco guitars too and the result is excellent. Many of the old school spanish luthiers applied their own bracing pattern which many of them developped during their lifetime to an individual design. Professional luthiers do not consider the bracing pattern as something which is to be separated from the whole. They always use a specific bracing pattern as part of a whole system. I think it's important to get the so called "big picture" of guitarconstruction. The bracing pattern is to my opinion not the most important factor in the guitarmaking process allthough it has an influence but it's just one of many, many more. José Ramirez wrote in his book "things about the guitar" that he spent a lot of time in his earlier years in order to experiment with new and innovative bracing patterns. The result was disappointing though, as non of the new bracing patterns did result in a better tone than any of the guitars with a traditional bracing pattern. His conclusion was, that there must be other factors who could more dramatically improve the sound of a guitar than the just the bracing pattern.

However there are some rules that really seem to change the voicing of the instrument.

It's the so called focal point of the fan bracing. A focal point around the 8,9,10th fret will most likely make the sound of guitar more open and somewhat warmer while a focal point around the 11th and 12th fret results in a brighter tone with more trebles. A focal point in the upper frets (11+) will increase the lateral stiffness of the soundboard which may result in a stronger treble response. But as already mentioned the focal point is also only one part of the "big picture".

Today there are mainly two bracing patterns considered to be superior for flamenco guitars. It's the 1933 pattern by Santos Hernandez and the 1951 pattern by Marcelo Barbero.
The correct thicknessing of the soundboard, the correct thicknessing and shaping of the braces is easily ignored by newstarting luthiers, but this factors may be even more important than the bracing pattern. All this factors depend on the soundboard material that you have on hand when starting to build. Therfor it is actually a mistake to build a guitar exactly to the specs indicated on a blue print. The reason is, that the luthier who built the originial instrument worked with different materials with different physical and acustical properties. This fact should not be left out.

I wish you a successful building of your first guitar.

Armando




Guest -> RE: BRACING / STRUT PATTERNS (Jan. 4 2006 8:14:06)

quote:

For example, Anders once mentioned that he only uses ONE harmonic bar. whereas my guitar has TWO


Bop bop bop. James. I said that my guitars have one UPPER harmonic bar.

Most makers work a traditional 5 or 7 piece strut, with or without closing struts. I think that many makers here in Spain have their own "formula" of how to do things. Me to.

Everything might look the same, but remember that there might be a big difference in something that looks similar to the eye, when we talk about differences in tenth of milimeter. A lot of things you feel more than you see.

You can make very nice flamenco guitars using Torres bracing pattern, in fact more or less all traditional bracing (abanico) comes from Torres, and remember also that Torres made MANY different bracing systems............

BTW: 2,6 - 2,7mm thick soundboard is very thick for spruce. That's what I do with cedar!!!! A spruce topped flamenco guitar should be around 2 - 2,3mm (IMHO) depending on the quality of the soundboard.




JBASHORUN -> RE: BRACING / STRUT PATTERNS (Jan. 4 2006 13:23:03)

Thank you Armando and Anders! very helpful information- exactly what I wanted to know. I have already glued the fan struts in place, so can't change them now, but I will bear it in mind for my next guitar.
The soundboard... Hmmm, my teacher told me to make it 2.6-2.7, and I did think it was quite thick at the time. I will try and get it down to 2.3 with a scraper plane. It is medium quality Spruce, but I have already glued in the rosette, so I'm not sure if I can get much off it... lets see.


Thanks again!


James




JBASHORUN -> RE: BRACING / STRUT PATTERNS (Jan. 6 2006 12:37:27)

quote:

Bop bop bop. James. I said that my guitars have one UPPER harmonic bar.



Hang on, Anders...

One upper harmonic bar?

By this do you mean that you don't use another smaller bar just above the main upper bar?

On my guitar, I used an extra bar just above the main upper harmonic bar because my teacher told me this would help stiffen the soundboard the therefore increase the treble response (brightness).

I also used two small struts running perpendicular to the upper and lower harmonic bars, as I was told this would do the same thing.


Please let me know what you think about this, as I could plane the other struts off if that would give the guitar a better and brighter tone.


Thanks very much.


James




Armando -> RE: BRACING / STRUT PATTERNS (Jan. 6 2006 14:35:00)

Hy JBASHORUN

Allthough i'm not Anders i'd like to give my comments as well.

quote:

On my guitar, I used an extra bar just above the main upper harmonic bar because my teacher told me this would help stiffen the soundboard the therefore increase the treble response (brightness).


Some Luthiers put an additional transverse brace in between the end of the neck and the upper harmonic bar. Others use a batch and some Luthiers none of it. Most flamenco guitars feature a batch in this area. The main purpose of this additional bar or batch is to stabilize the soundboard beneath the ebony fretboard. Ebony absorbes and evaporates easily room humidity. This will cause the fretboard to either swell or shrink. This in turn will cause a stress to the soundbaord due to the fact that the soundboard is rather sensitive to lateral shrinkage. The aim of this batch or brace is to avoid cracking of the soundboard along the fretboard. Acustically i don't think that a batch in this area will have a great influence on the tone.

quote:

I also used two small struts running perpendicular to the upper and lower harmonic bars, as I was told this would do the same thing.


If i understand you correctly you refere to the area at the left and right side of the soundhole. Most luthiers glue either a batch to the left and right side or even a whole batch in form of a ring around the entire soundhole. The main function of this batches is to support the area below the rosette, because the rosette channel takes away stiffness
from the soundboard in this area. This need to be compensed. Some Luthiers use bars instead of batches to support this area. Some luthiers add an additional short brace on either side of the bathches, but this is mainly seen on classical guitars. In regards to the sound i always make sure the batches are as light and stiff as possible and everywhere well rounded and sanded. That's all. Whether your soundboard is too stiff or not is difficult to say, as this depends on the quality of the soundboard material, but 2.7mm is most likely too beefy for a spruce top unless the soundboard is terribly floppy.

If you have made your soundboard rather too thick, you may still tapper it towards the edges to about 2.2mm. This would make your soundboard somewhat lighter, which is good for a flamenco guitar. It would also lower the pitch of the soundboard and make the soundboard somewhat more flexible. This could add basses to the guitar, but does not necessarily take away trebles, as long as the soundboard is stiff enough in the center area. The braces could be shaved to a rather flat profile (around 3mm height) unless the soundboard material is too floppy as already mentioned above.

I hope this helps a bit.

good luck

Armando




TANúñez -> RE: BRACING / STRUT PATTERNS (Jan. 6 2006 15:40:57)

James,

I'd like to add my 2 Euros for whatever it's worth. You shouldn't build a certain way or add or subract braces because someone told you to do it this way. You need to let the top wood dictate what needs to be done because not every top is the same. Even tops that are the same thickness. Some will still be stiffer than others. You need to listen to the tap tone and go by the flexability of the top.

For example, if you already have a spruce top that is very stiff and you start adding braces in certain ways because you were taught to do it this way, you'll end up making the top very stiff. Possibly stiffer than it should be. If you start building to a strict formula without considering the stiffness of the tops, you'll start getting inconsistant results. I'm not saying a strict formula is wrong but you need to know just how much of the braces to shave off to compliment the thickness of the top. Learning how to listen to the top and work the flexibility will come with experience. This can't really be taught but you'll get it sooner than later.

The brace right above the top harmonic bar and below the heel (if this is what your talking about) isn't really so much for acoustic purposes but for structural ones. This helps prevent the top splitting alongside the fretboard if the fretboard were to shrink. This brace helps counteract the pulling of the top if it starts to shrink in with the fingerboard. Doesn't always work depending on much it shrinks but it does help a lot. I believe Armando already mentioned this.




Guest -> RE: BRACING / STRUT PATTERNS (Jan. 6 2006 17:58:12)

James.

I will strongly recommend you to stay with the Torres plan for your first guitar. It's the mother of all guitars.

The only problem I see is that your soundboard is to thick... If it's so floppy that you have to work it so thick, it's worthless and will never sound. As far as I remember, the Torres plan you can by says something around 2mm, but I might be wrong. On a very good soundboard (stiff) you can go down to 2,1 - 2,2 in the center and 1,9 - 2mm in the sides, but don't go so thin on the sides on your first guitar, maybe you will scrape or sand to much away on the edges when yo trim the bindings of finish sand the guitar. That's a typical beginners error and I,ve done it myself.

I personally use a 2mm batch between the heel and the UPPER harmonic bar. This because of what Armando says, to minimize the risk of soundboard cracks to the sides of the fingerboard.




JBASHORUN -> RE: BRACING / STRUT PATTERNS (Jan. 7 2006 20:00:36)

Thank you Armando, El Zurdo and Anders!

I will try and keep to the Torres pattern as much as possible... but I do want my guitar to sound distinctly Flamenco rather than just being classical guitar with golpeadores. I guess maybe the soundboard thickness might be the crucial factor then, and I'll try to thin it down. The trouble is that I have already glued the struts and harmonic bars in place, so I can't really test the flexibility very effectively. I just blindly followed my teacher's instructions on the best thickness according to how flexible he felt the soundboard was. As it is my first guitar I had no idea how to tell.


quote:

If I understand you correctly you refer to the area at the left and right side of the soundhole. Most luthiers glue either a batch to the left and right side or even a whole batch in form of a ring around the entire soundhole. The main function of this batches is to support the area below the rosette, because the rosette channel takes away stiffness
from the soundboard in this area. This need to be compensed. Some Luthiers use bars instead of batches to support this area. Some luthiers add an additional short brace on either side of the bathches, but this is mainly seen on classical guitars.



I have already glued the soundhole patch in place... I used 2 strips of wood either side of the soundhole. I also added a small strip to above and below the soundhole (just inside the harmonic bars) as I was told this would also stiffen it and make the sound brighter.
But I did add the 2 braces on either side of the soundhole patches, which you said is mainly used on classical guitars... The model I am following is a Torres (?) Classical style, so I just put them in. None of my teachers knows much specifically about Flamenco guitars, so they weren't sure.

If you have time, let me know if you think I should plane off these outer braces, and what effect it will have on the sound (if any).


Thanks again!



James




Armando -> RE: BRACING / STRUT PATTERNS (Jan. 10 2006 11:14:22)

Hy JBASHORUN


quote:

If you have time, let me know if you think I should plane off these outer braces, and what effect it will have on the sound (if any).
^

To be honest i can't tell you out of my own experience whether or not these additional bracings left and right side of the soundhole influence the tone of the guitar as i have not built any with such bracings yet. My feeling sais, that there wouldn't be a remarkable difference in tone. If there is any, it would be very slightly and probably not be noticed by the majority of people. From the logical point of view it would most probably have a an influence on the trebles because it causes additional stiffness to the soundboard in the area of the soundhole. I don't think it's a mistake to have placed them. I would not take them off anymore. I'd rather make sure to get the right stiffness in the lower bout area. In case that the soundboard is too stiff, i'd most likely plane down the braces in order to get the soundboard to the right thickness first. After this i'd re-brace the top. I think the additional workload is worthwhile because the soundbord will have the most influence on the final sound character of your instrument. It may take you up to 200hours of work to get the instrument completed. Now you are still in the beginning. once the sides are attached to the top, it will be much more difficult to make any adjustments ot the top.

That's all my opinion. At the end you must be clear about what yout going to do.

regards

Armando




Guest -> RE: BRACING / STRUT PATTERNS (Jan. 10 2006 15:24:25)

I Totally agree with what Armando has just written. These are very advices.

I build with these little finger braces to the sides of the soundhole, and have build without.... I´m not sure I could see any difference. The reason I use them I that the area around the soundhole is supposed to be as stiff as possible, in order to let the sound out without to much turbulence.

Don´t worry about the Torres layout. It will work if you get the right stifness in your soundboard.

I´ve said this before. IMO it´s not so much the bracing layout, but much more how you work it which matters. I build 7 piece fan with 2 closing struts and a slightly slanted lower harmonic bar, but this basic layout can be worked in so many ways that it´s almost endless.




JBASHORUN -> RE: BRACING / STRUT PATTERNS (Jan. 10 2006 18:17:19)

Thank you SO much Armando and Anders!!! [:)]

I will leave the small struts to the sides of the soundhole as they are. I will also try and thin the soundboard down to around 2.0- 2.3mm. I tried flexing it today, and there is still some flexibility in it... even with the bracing on. not so thin it might break, but still noticeably flexible. But I will try and make it thinner.

Thanks again... lets hope it sounds as good as the guitars you guys make (when its finished)!



James




JBASHORUN -> RE: BRACING / STRUT PATTERNS (Jan. 10 2006 18:23:41)

quote:

I build 7 piece fan with 2 closing struts and a slightly slanted lower harmonic bar


One last thing, Anders...

If you have time, please tell me at what angle the lower harmonic bar is slanted... or whether it is just the top sanded/planed at a slant.

I know its just personal preference and there are many different styles, but from what I hear your guitars sound better than most.


THANK YOU!!!



James




Guest -> RE: BRACING / STRUT PATTERNS (Jan. 10 2006 21:49:43)

It´s about 10 - 15 degrees




Armando -> RE: BRACING / STRUT PATTERNS (Jan. 11 2006 18:36:10)

Hy JBASHORUN

quote:

Thanks again... lets hope it sounds as good as the guitars you guys make (when its finished)!


I understand that Anders is a professional luthier whereas i'm just an amateur luthier. Therefore i can't measure or compare myself with him.
I'm just working for my dayjob during the week. The only time to spend for luthiery is on saturday afternoon. That's why it takes me one year to build a guitar. Nevertheless i consider myself to be passionate for the flamenco guitar and the guitar luthery. I've just read all books and articles i could find about this subject. The fact that Anders shared most of my opinions or advices is very rewarding for me. It means that my study was not in vain and i'm on the right path to go. It could be an example for you as well how much knowledge you can gain in quite short time if you really dedicate yourself to the subject.
I think that my theoretical knowledge is more advanced than my practical experience, allthough i had good success with the two flamenca blancas that i have built so far. As already mentioned i'm looking forward to go online with my homepage www.spanishguitars.ch before the end of this month. You will then be able to see pictures of my guitars and the making process including videoclips with sound samples.

good luck

best regards

Armando




JBASHORUN -> RE: BRACING / STRUT PATTERNS (Jan. 11 2006 23:19:14)

Thanks again Armand!
I am new to guitar making, so I haven't got many books and much technical knowledge yet. But I am learning fast. Apparently it takes my teachers 8 weeks to make a guitar (full time), but it will take me over a year for my first guitar (full time too).
I look forward to when your website is up and running... I will visit, and see/hear what your guitars are like.


Good luck with your luthiery!


James




Guest -> RE: BRACING / STRUT PATTERNS (Jan. 12 2006 16:17:04)

Armando.

Tell us when your webpage is up and running.
A lot of amateur builders build very fine instruments. Dedication and time is a very possitive thing in building.
The last thing, the touch, is what takes a lot of time.... A life or more.

Also, there are so many things which are difficult to explain, because they are intuitive....[8|]




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