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PostPosted: Fri Oct 23, 2009 6:16 pm 
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Cocobolo
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First build. I got stalled because of work but I am ready to "close the box". Has anyone done side braces like this before? What do you think? I know what they will do if I imitate Martin or Gibson..... I just wanted to know if you've tried tall sidebars before?
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BTW all the ook on the first image was filler wood that was cleaned up


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PostPosted: Fri Oct 23, 2009 6:30 pm 
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Brazilian Rosewood
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The finger braces are way oversized. Still it is best to do something and learn. You can always reach in and cut them down later

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PostPosted: Fri Oct 23, 2009 6:31 pm 
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What are you trying to accomplish? You seem to be using massive braces in an area that doesn't require much structural support but fairly light, heavily scalloped braces in the areas under the greatest tension. Surely there's some thought behind that choice.


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PostPosted: Fri Oct 23, 2009 7:08 pm 
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Try it and learn from it......it's good to ask for opinions, but don't let that sway you from forging your own path, what you find might surprise you.

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PostPosted: Fri Oct 23, 2009 7:41 pm 
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Yammie? Is that you?

Well, you know what I think! ;)

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PostPosted: Fri Oct 23, 2009 10:45 pm 
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Cut those small,but tall braces WAY DOWN to a max. of 1/4" high. The bridge plate will prevent decent vibration also.


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PostPosted: Fri Oct 23, 2009 10:50 pm 
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Same suggestions here as from several other folks. Cut those finger braces down to about 1/4" high and taper them
down to 1/16" or less where they will meet the kerfing. Next time use a much smaller bridge plate to provide a good
interface for the string ball ends and to provide just enough structural integrity under the bridge without adding so
much weight and mass in that area.

Regards,
Kevin Gallagher/Omega Guitars


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PostPosted: Sun Oct 25, 2009 6:12 am 
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Cocobolo
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So, you guys have tried this?


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PostPosted: Sun Oct 25, 2009 7:14 am 
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Brazilian Rosewood
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Building like that? Not many I think, because it doesn't seem to be very intuitive. You need stiffness to resist the pull of the strings and that is not the best place to put it. You want the outer part of the top to be flexible so it can pump some air.

Abrupt height changes are bad structurally. It is like a car without suspension. Your other braces look much better, with two exceptions: the inner scallops of the X are a bit too abrupt again, and the upper transverse seems weak.

Compared to what the UTB of a classical looks like, and for only 90 pounds of tension, most steelstring tops I see seem to have ridiculously weak UTB's, while the tension is double. They are feathered down to near nothing and to top it, there is a big hole drilled in it! gaah

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PostPosted: Sun Oct 25, 2009 7:28 am 
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Brazilian Rosewood
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One thing I noticed also is how hard you have the scallops . Think about the load on the top. The rational force is concentrated at that point and you appear to have it pretty weak , then you over compensated with a very large plate. Those finger braces are so over done but again . you often learn more from a failure than you do a success.
On the top , you have the pull and rotation of the bridge from the bridge to the neck block , then behind the bridge you have a tensional load. With braces that thin at the bridge , you may make the headroom of this guitar very limited. It isn't just about making a light top , you have to design the bracing for what you are trying to accomplish.
I am a traditionalist in my building style but have done some contemporary builds. Shape of the bracing can and does influence the voice of the guitar. I see you also roughed up the braces when shaping . I think I would recommend to start over and rethink this a bit. It is hard to give good advice without it in my hands . How high are how thick is your bracing ? How thick is the top. Also at what point is the bridge sitting . And what scale length is the bracing designed for ?. Where are the corners of the bridge catching ?
We don't want to discourage you and I am sure others may disagree with me , but I see some things here that if laid out wrong can cuase you some problems later. Also if you think you are right build it and see what you get. One never knows , True discovery never comes from status quo .

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PostPosted: Sun Oct 25, 2009 8:27 am 
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Alexandru Marian wrote:
Compared to what the UTB of a classical looks like, and for only 90 pounds of tension, most steelstring tops I see seem to have ridiculously weak UTB's, while the tension is double. They are feathered down to near nothing and to top it, there is a big hole drilled in it! gaah


That is a curiosity, isn't it? Perhaps it is the other way around - the transverse bracing above the soundhole in the classical guitars is overdone?

Would a much heavier UTB in a steel string guitar hurt it's tone or volume? Would a much lighter UTB in a classical do the same?

The open UTB's in some classical guitars seem to be an experiment in this direction, although I'd guess that the people who have tried them have not concluded that they are an improvement across the board. I notice that Jose Romanillos goes back to a solid UTB when he does his more Torrez-style soundboards.

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PostPosted: Sun Oct 25, 2009 10:28 am 
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Who knows, maybe we are over doing it, but I also don't hear much about the notion of "neck reset" in our circle :)
My latest has open bars. I am sure it is still giving good support. I've used some very heavy spruce and I can't flex it at all, the profile is 5/16 x 5/8 with bullet-shaping. The lower transverse is knife shaped to remove some more mass.

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PostPosted: Sun Oct 25, 2009 10:36 am 
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Here is a pic. The important thing is that, open or not, there is no scalloping so the thing does not flex. And after the short wide patch, there is a third brace coming up, similar to the popsicle brace on a Martin, only that is is just 5/18 wide.


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PostPosted: Sun Oct 25, 2009 11:48 am 
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Cocobolo
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Todd Stock wrote:
If the guitar sounds worse after starting your trimming, retain a patent attorney to handle intellectual property stuff and trademark "Tone-o-matic Finger Fins" and "Mega Magic Harmonic Fingers"....I promise not to counterfile ;)

I'm gonna hold ya to it! Ya made me laugh.


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PostPosted: Sun Oct 25, 2009 11:56 am 
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Cocobolo
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Ok here is my theory.
Don't play pool against me. I'll kick yer butt. I am treating air as a Pool ball and the braces as bumpers. I know what will happen if I copy my Martin sample braces. I am pretty sure I will know what will happen if I copy what I have seen and heard. This is a learning thing for me. I figure my first build is gonna crap out for 300 reasons. Why not learn from it?
Theres a reason I started from scratch and not a kit. Not sure what the reason is....... lol


BTW I based some of my "theory" on a side conversation with a fellow named Bill Collings and another fellow that wants to remain nameless :) Lets see what we get.


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PostPosted: Sun Oct 25, 2009 2:41 pm 
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Koa
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Might sound like a '60 Caddy


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PostPosted: Sun Oct 25, 2009 3:12 pm 
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Brazilian Rosewood
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If your first guitar sounds like crap, then you will know that those tall braces were a bad idea? No, there may have 299 other reasons it doesn't sound good. But you will never know if if was the tall braces or something else.

A first guitar is not the place to try out new theories. You should build to a plan and try to get something decent, then start experimenting on the second. Surely you have heard this recommendation before?


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PostPosted: Sun Oct 25, 2009 3:35 pm 
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Brazilian Rosewood
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A few of us here have built over the century mark of guitars , and I hope your enthusiasm remains strong . I agree that your first guitar should be of a stock print or some other base kit guitar . Once you get the building process and an understanding of the physics and engineering involved you will have a better understanding .
Don't think your first guitar will be your best guitar . As Todd points out it is more an exercise in process and technique. Have fun keep a building log and learn . Many of my early opinions have been tossed aside as I gained experience and training.

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PostPosted: Mon Oct 26, 2009 10:15 am 
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Your best guitar will usually be your next one. Best advice if you want to experiment is to start with a known and make small incremental changes one change at a time.
Like this! laughing6-hehe
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PostPosted: Mon Oct 26, 2009 11:33 am 
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Interesting idea/concept. I do agree that a first build may not be the best place to experiment, but I can't say don't do it...because I did! laughing6-hehe

One idea for the baffling...maybe do the baffles on the back plates so you can leave the bracing on the top alone. If you used a non-permanent glue (hide glue, etc) you would have the option of moving the baffles around without changing anything on the top. A strong double-stick might work too.

Interested to see how it come out when done!

Matthew


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PostPosted: Mon Oct 26, 2009 11:51 am 
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i am baffled at your idea of using baffling. i may be the only one that doesn't know what your talking about but whats baffling in a guitar? idunno


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PostPosted: Mon Oct 26, 2009 12:27 pm 
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Hey John -

Delighted to see you're tackling your first build.

Lots of more experienced folks have commented - I'm on build #5 - so....."what they said".

One new thought, though. Dana Bourgeois gives a pretty interesting presentation on his approach to scalloping braces, through holding the braced top lightly between forefinger and thumb, and tapping on the top to listen for a variety of tones, while tapping at various points on the top. His goal is not to go for a specific note or pitch - but rather a multitude - from various tapping points. You can find a pretty good description of his technique by googling "Bourgeois voicing". It's not specific about WHERE to remove mass (as he says "where it looks overbuilt" :? but then again some of this just isn't going to happen without some trial and error.

So, my only point is, given some of the feedback that the tonebars are overbult and the bridge plate may also be large, try tapping it - see if you're getting tones that sound musical and varied.

Have fun!


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PostPosted: Mon Oct 26, 2009 1:04 pm 
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I'm not one to discourage experimentation, even on a first. I experimented quite a bit on my first, though I had the guidance of an experienced builder on the bracing, and, though the bracing doesn't look quite like a Martin, it's not that weird either. There are other somewhat weird things about that guitar, but nothing that really flies in the face of traditional wisdom (or basic facts of how guitars and acoustics work). Anyway, it sounds really good (not just my own opinion) and the playability is very good as well (I took a very long time building it and studied/worked hard to get all the playability factors right).

Now, as to your bumpers, my first thought is that air doesn't move around inside a guitar like a pool ball. In fact, it hardly moves at all. Sound waves travel from here to there, but the air molecules themselves just kind of jiggle a bit, they don't go anywhere (this is true not just inside a box like a guitar, but everywhere). The air is simply the medium through which the sound waves travel. Am I telling you something you already know? Is it sound waves you want to reflect in some way?

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PostPosted: Mon Oct 26, 2009 5:46 pm 
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Todd Rose wrote:
Is it sound waves you want to reflect in some way?

That was the idea :idea: What you said made sense.


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PostPosted: Mon Oct 26, 2009 7:28 pm 
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I think it's anybody's guess what effect the tall finger braces might have on the complex behavior of the air resonances in the box, in terms of acting as reflective surfaces - my own guess would be very little audible effect at all. On the other hand, as others have suggested, the drastic stiffening of the top in that area will certainly have a significant effect on the behavior of the top.

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