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View Full Version : To Butt or Not to Butt: That is the question



sequoia
05-21-2015, 10:39 AM
I've noticed that on my top bracing pattern blueprint and neckblock sizing dimensions, that the top brace furthest north comes very close to my neck block. On my past ukes, when I'm fitting my top for gluing I butt the top brace to the neckblock and then ease it back about an 1/8 inch to leave a gap. My theory has always been that the top braces touch nothing including the linings leaving them free to vibrate the top. Floating if you will. Now I'm thinking that the designer (unknown) wanted the top brace to butt firmly against the neck block. I would think a butted top brace would really kill any movement on that upper bout killing the top in that area. Maybe the idea is to transmit the vibrations from the neck and neck block into the top by directly attaching the block to the brace? Maybe the idea is to kill that area? It certainly would be structurally stronger. What do you think? To butt or not to butt?

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Beau Hannam Ukuleles
05-21-2015, 12:28 PM
butt it any way you can

tobinsuke
05-21-2015, 01:46 PM
butt it any way you can



Rats! Why can't I think of a smart alecky comment?! ��

sequoia
05-21-2015, 02:24 PM
butt it any way you can

Butt seriously Beau, attach right to the neck block? I haven't put on the back yet so I can still slide a shim in there and glue it up. Certainly makes a strong structural connection.

BlackBearUkes
05-21-2015, 03:28 PM
You have to ask yourself, what you will be gaining by using such a large block in the first place. If you are trying to get the top to vibrate that much in the upper bout, is using that block going to hinder or help? Also, I hope you are tucking the transverse braces into the kerfings or linings. If you are not, why not?

Allen
05-21-2015, 03:38 PM
Any guitar like instrument it trying to fold itself in half and swallow itself down the sound hole. So the upper bout needs to limit the neck and fret board from rotating up and into the sound hole. Now within reason, you're design and bracing intent should accommodate that tendency.

sequoia
05-21-2015, 06:47 PM
You have to ask yourself, what you will be gaining by using such a large block in the first place. If you are trying to get the top to vibrate that much in the upper bout, is using that block going to hinder or help? Also, I hope you are tucking the transverse braces into the kerfings or linings. If you are not, why not?

Now don't flame me Duane and I will try to answer your questions. Aloha.

1) If you look at the picture, the block isn't really that large. It not a monolithic square piece of wood, but a three way laminate with the the radiused part that contacts the sides pretty thin. It has two upper and lower parts that support the neck and back. A 'U' on its side. I was inspired by a design from an SMD kit because I liked it and it makes sense to me. The part that contacts the upper bout crossbrace is only about 1/2 thick. Why do I do it this way? Probably because that is the way I did it when I first learned and I continue to do it because it is the only way I know. Is it the best way to make a neck block? I dunno. Maybe and maybe not, but it works for me just dandy.

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2) I used to laboriously cut out my linings and feather the braces right up to the sides. I don't do that anymore for a couple reasons: I think it looks ugly, is extra work and in the end doesn't make that much difference. So now I just feather my braces up to and a hair under the lining. Theoretically I suppose one should get the maximum span on the top brace by running them up to the sides, but I think that little extra isn't going to effect the sound.

Aloha

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DennisK
05-21-2015, 07:00 PM
Either use a smaller headblock, or butt it and glue it to the brace. If it is attached to the brace, make sure the brace is good and strong because that focuses the neck rotation stress onto it, and can warp it over time.

With a small headblock, I like to use A-frame braces, which are notched into the headblock and run all the way down past the soundhole to the lower cross brace. Spreads the stress over a larger area than the headblock extension style.

EDIT: Didn't see your new pictures. That's quite a short span from the edge to the upper brace, so the A-frame style might not really fit on that model. Also, Pete makes a good point that it probably doesn't even really matter on such a small, low tension instrument... I mainly build steel string guitars, which are a lot more susceptible to cold creep.

Pete Howlett
05-21-2015, 07:01 PM
Your design is over engineered for a ukulele. Also you should always tie transverse braces into the lining. It's good luthiery practice.

sequoia
05-21-2015, 08:43 PM
Your design is over engineered for a ukulele. Also you should always tie transverse braces into the lining. It's good luthiery practice.

I'm hearing you Pete and Dennis. Actually the phrase "over engineered" is music to my ears because why do something if it is unnecessary? The things are a pain in the ass to make and if it isn't needed then I'm more than willing to abandon the design. I've actually been thinking of a simple unradiused block to simplify things. A flat neck block profile would save me an immense amount of work when it comes to neck-body connection. I'm all ears.

Now tying off the transverse bracing to the lining makes structural sense to me, but don't we want that upper bout to move? I visualize it as giving some treble to go with the lower bout. My research tends to show me that I'm wrong and that the upper bout is dead and shouldn't move. At least that is what the classical guitar builders say. But ukes ain't classical guitars. You will have to forgive me. I am a student and self taught and I struggle with these concepts. Sometimes I feel like I'm building in a vacuum and I get lost. Thanks for your input.

Beau Hannam Ukuleles
05-22-2015, 09:29 AM
On ALL my instruments I add a wood segment (as wide as the headblock) between the end of the head block and upper transverse bar- for the reasons Allen mentions.

Here is a guitar segment- the ukes have a shorter bit. Some makers make the top of the headblock long enough to reach the entire way but i think its a waste of good wood- just fit an nice bit of off cut into it- its not hard to get a nice fit
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Moore Bettah Ukuleles
05-22-2015, 10:03 AM
Personally I'd be more concerned about the lack of sound hole bracing. I'm also in the camp the believes that the upper bout adds little if anything to the resonance of the top. I don't want that area to move. Also, the fretboard, if glued on, will add some structural support.

little timber
05-22-2015, 11:26 AM
Your design is over engineered for a ukulele. Also you should always tie transverse braces into the lining. It's good luthiery practice.

Why tie the braces into the lining?

Allen
05-22-2015, 12:57 PM
Your transverse braces should be tied into the linings to help support the ends.

If either to top or back get a good knock they will flex to the point where the brace will pop off or crack at the end of the brace if it's not supported.

Beau Hannam Ukuleles
05-22-2015, 01:25 PM
Personally I'd be more concerned about the lack of sound hole bracing. I'm also in the camp the believes that the upper bout adds little if anything to the resonance of the top. I don't want that area to move. Also, the fretboard, if glued on, will add some structural support.

Yep- i really don't think the headblock or upper transverse brace can ever be tooooo big.

And tuck both tranny braces in, like everyone has said :)

sequoia
05-22-2015, 08:22 PM
Personally I'd be more concerned about the lack of sound hole bracing..

I think you nailed it Chuck. I too am concerned about the lack of sound hole bracing. The reason is I I know where the bodies are buried and cut the rosette a little too deep and that top is thin creating a structural instability. But the jist of the question was as I tie off and butt everything up, haven't I killed any hope of letting that upper bout move? I think the answer is: Yup. And that is how it has to be. Structure trumps sound every time.

Pete Howlett
05-23-2015, 05:12 AM
Sometimes you simply have to bow to the wisdom of tradition. My first brace, the one under the fingerboard is flat and wide: 3/8" x 1/2". I have two strengthening 5bars that are 3/8" wide by 1/8" thick that are glued either side of the soundhole. The next transverse brace is 5/16" wide x 9/16" thick. This second brace and all braces below it are radiused to 22'. Because this part of the front is in tension and the soundhole fully supported with the transverse bars notched into the sides you have strength where it is needed and flexibility (you can make the front 0.072" because of the tension)so you derive from sound principals a strong responsive top. Now all of this 'technical' stuff I developed from the thesis I wrote for my degree on the construction of the classical guitar. This paper was backed up by research and interviews with top British luthiers - if you really want to know. It's not just experience that is required to make a good instrument. It is sound construction methods, backed up by tradition and allied with empiric research. Oh, and you have to 'have it' or 'get it' because either you do or you don't - like anything in the music trade!

pt66
05-24-2015, 12:55 AM
Braces being tied to the lining may prevent it from popping off at the end but I have seen plenty of cracked and broken braces where the crack has started just off the top or back. A popped brace is easier to fix then a broken one.

jcalkin
05-24-2015, 08:24 AM
I dislike being told what I have to do, either by other luthiers or tradition. I built a pair of strangely shaped steel string guitars with no braces that reached the lining, either top or back. They sounded fine and gave me no troubles over ten years or so. All plates were dead flat (no radius) and never caved or bulged. I had no cases for them so they got a little dinged, but I can't remember ever giving any instrument a hard knock.

I never take such construction liberties with instruments meant for sale, but I think that any design that lasts ten years with no problems is a good one. I don't warrant instruments against rough handling and don't build heavy enough to have them live through it unscathed should they be mistreated. I'm beginning to hear about instruments I built twenty or more years ago and they are still making music the way they were designed to. If you're not dependent on making instruments for a living I think its a good thing to build some risky ones and keep them around. They will teach you more than anyone else's advice.

Hluth
05-24-2015, 12:48 PM
The heel block in the pictures looks like a Spanish heel with the neck cut off at the upper bout. This kind of block does add additional support at the end of the fret board, and I also think it should be glued to the transverse brace. The brace should also be tucked under the lining. One of the favorite heel joints I make is pictured below. There actually is no joint, and the structure between the "joint" and first brace is both strong and light.

79888 79889

pt66
05-25-2015, 02:41 PM
I agree with jcalkin. If we all do what everyone has always done there is no progress. If C.F. Martin would have said a dreadnaught guitar is outside of tradition, then what. I don't tie my braces into the lining. Never have and never will. I have been building for 52 years and it works for me.

Pete Howlett
05-25-2015, 02:53 PM
Progress always reaches a zenith. Some things just cannot be developed any further....IMHO

pt66
05-25-2015, 04:51 PM
"Progress always reaches a zenith. Some things just cannot be developed any further" I feel sorry for you if you believe this.

Pete Howlett
05-25-2015, 07:38 PM
As you cite Martin....don't see much development there. Been using the X brace system forever and though they have fiddled about with the forward position of the X they eventually reverted to the pre-war position which indicates zenith reached and if anything, regression! I also think it's a high risk strategy to experiment on clients who are paying for something a little more than a guess. As with all things there are rules and boundaries. I am pretty much happy with the sound and construction I have evolved to - only recently did I "thicken-up" the brace under the fingerboard. I don't consider this progress; it's development. I use a different bracing pattern on my spruce top tenors and CF in my baritone necks (yes folks, I have succumbed). I don't see what more i can do to 'progress' my design hence my view I have reached the peak and since my clients continue to order and re-order from me I would consider it a high risk strategy to change what is a proven formula. Now I don't need to be pitied for this approach - this is my business and having arrived at a point of success, I'm not going to change direction for ideological reasons... that would be tantamount to business suicide. I need to put food on the table, not ideas.

pt66
05-26-2015, 10:26 AM
Martin currently uses 4 different X brace patterns and some have variations within the pattern depending on the series guitar. You may have reached your zenith but some of us are still trying to advance the art and science of luthierie.

BlackBearUkes
05-26-2015, 10:36 AM
So we all know to whom we are talking, who is pt66?


Martin currently uses 4 different X brace patterns and some have variations within the pattern depending on the series guitar. You may have reached your zenith but some of us are still trying to advance the art and science of luthierie.

pt66
05-26-2015, 05:06 PM
I just went to C. F. Martins web sit and they show 5 X bracing patterns. My name is David Schneider. I live in Illinois. I built my first instrument as a freshman in high school. I owned my own guitar repair business. I had an article published in American Luthierie recently. I build guitars, mandolins, ukuleles, banjos and dulcimers. I worked at C. F. Martin the summer of 1966 before joining the Navy. Any other questions?

Pete Howlett
05-26-2015, 07:30 PM
It's still X bracing ain't it?

I just don't buy the line you must always seek to improve on the design. I think once you have settled on your design as I have, you then spend the rest of your life trying to improve the execution of it. That's a whole other story.

Michael N.
05-26-2015, 11:44 PM
In terms of Nylon Guitar design there has been very, very little improvement in the last 150 years! Even some of the so called improvements are a little contentious. I can only really think of the Lattice and the double Top designs. Not everyone see these as an improvement though, in fact some think that they are a backward step.
The rest are really old design factors that have been reintroduced - cutaways, soundports, adjustable necks, fanned/scalloped frets etc. Even the X brace pre-dates Martin, although not by much. When something is relatively simple (as plucked/bowed instruments are) it's mighty difficult to come up with absolute improvements. Our ancestors weren't idiots and you only have to look at how much development was going on in the 19 th century to realise just how experimental these people were. The vast majority of these experiments/marketing ploys (countless thousands) never saw the light of day, probably for very good reason. It didn't stop them from trying to tell us all what great ideas they had though.

pt66
05-27-2015, 04:23 AM
I guess we got away from the original post. For those how have a design that works for them, that's great. I have too many "what ifs" in my head to follow a plan over and over again. When I build an instrument that is not in the range of normal and someone buys it that's great. If they don't that's okay too. I understand if you make your living at this you have to be consistent to a degree. In my mind there is never just one way to do anything. Make chips and enjoy life.

Lapsteel
09-03-2015, 03:50 AM
"Principles" , not "principals"

sequoia
09-03-2015, 07:24 AM
peĚdanĚtic (pə-dăn′tĭk) adj. Characterized by a narrow, often ostentatious concern for academic knowledge and formal rules: a pedantic attention to details.

Philstix
09-06-2015, 07:24 AM
Their, they're, there is no reason to insult someone for pointing out proper use of English words. Although I must admit there have been occasions when the use of the wrong spelling for a word on the forum has kept me laughing for weeks. Since the purpose of the forum is communication it wouldn't hurt if we were all a little more pedantic.

lauburu
09-06-2015, 11:34 AM
Yes, the poor spelling of some of this forum's best contributors can raise a smile. It surprises me that people who are so particular about achieving perfection in the instruments they make can be so careless in their use of language.
However, it's our collective blend of skills that makes the world an interesting place.
I was lucky to have been taught the 3 Rs by Catholic nuns who insisted on getting it right first time every time. After a while precision in these disciplines became a habit.
If the Catholic nuns had taught wooodworking, I could be a master luthier by now. :)
Miguel