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I heard a great sounding classical at a concert this week. It was built in Ireland by Michael O'Leary and played by Berta Rojas. Great volume and projection, and fat, sweet trebles. I looked him up and saw that he builds in the Australian style--heavy laminated sides and back, lattice bracing. But the guitar did not have the tiring nasal quality of a Smallman. I've also been very impressed with a lattice braced guitar made by Jim Redgate, which I recall as sounding piano-like.

Sooo . . . I'm thinking to try lattice bracing a steel string. Does anyone know of attempts at this? I'd also appreciate any information on the details of lattice bracing systems, such as the spacing and angling of the lattice, joining of the lattice (I'm assuming lap joints like an X brace), use of CF reinforcement, etc. Any useful sources? I've found David Schramm's site, BTW.

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

Hi Howard,

John How has a run of ladder braced guitars, probably all parlors. Very handsome, the ones I've seen....

Howard - I can't think of the right web reference off the top of my head. For a different steel-string instrument, though, Graham MacDonald's bouzouki book shows lattice braced top plans for an Irish Bouzouki.

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Jim Kirby
kirby@udel.edu

Hi Howard,

I've used lattice bracing in conjunction with a traditional "X" brace system and the guitars sounded awesome. One thing I found was that the lattice system is inherently stiff so take that into consideration when you build one..... I make my lattice braces as thin as I dare. Yes, I used lap joints just like a main "X" joint, the spacing of the lattice varied a bit, but only to fit the specific sized guitar at hand. I hope this is helpful, give me a shout if you have any questions. You can hear three lattice braced guitars of mine on my website....1 is on the front page(youtube video) the other 2 are on my soundclip page.


Cheers,
Greg

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Gwaltney Guitars

Howard,

Michael Lazar had a great build thread at the luthierforum in which he built both a fan-braced and a lattice braced classical. He has furnished extensive photos and information on both layouts and, if I remember correctly was really pleased with the results of the lattice braced instrument. He described the response of the lattice braced guitar much like you have.

Here is the link:
http://www.luthierforum.com/index.php?showtopic=4944

Perhaps some discussion with him would be of value to you.

Regards,

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Peter

Howard-

You might give Sergei DeJonge a call. He builds lattice braced spanish guitars and traditionally braced steel strings. He has done experimental guitars in the past, so it is possible he has info on lattice braced steel strings. He and his wife, Devora, are nice folks - they have always been helpful in the past to me.

Good luck-

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John Lewis
Wannabe builder owned by 2 crazy dachshunds

I have been building all lattice guitars (classicals) for about 5 years now. It took me a while to get the sound that I was looking for though...the basses were very boomy and unfocused and the trebles were very thin. I have found this to be the case with a lot of lattice instruments. I am actually using an assymetrical design now which really brought my instruments to a new level. I use balsa wood with graphite sandwiched in between using lap joints to connect them. I am also using a arched/braceless back which has really helped the tone and volume enormously. I was actually thinking about building a lattice steel string (it would be my first steel string) and would be interested in your ideas. PM if you want to talk more.

Hi Howard,
I did a lattice braced steel string at the beginning of this last year.
The top was .050 thick, spruce bracing with .020 carbon fiber caps. I wouldn't trust balsa on a steel string unless you wanted to use it in an end grain fashion.
The brace angle was 90 degrees and each joint was a half lap. The bridge plate was inset into the bracing lattice and a pinless bridge was used.

I did quite a bit of development on this, primarily consisting of finite element models of various configurations of top thickness, brace angles, number of braces, sizes, etc... I also did fea models of my standard X braced top so I could compare the differences between the designs. Learned a lot!

There is a older GAL that has some information about the Smallman tops and some latticed braced steel string guitars by Jim Williams. I could look up the issue number if you'd like.
This top went onto a body that I use to experiment with. It sounded really great, very well balanced and alive. Everyone who played really liked it. The only thing I don't like about it is the .050 top thickness, it just doesn't seem robust enough to me. Humidity also reacts really fast on thin tops. My double tops are more robust, even though the skins are thinner, as they are supported everywhere.

Here's a jpg of the Cad model I did the FEA on, followed by a photo of the actual top.

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Jim Watts
http://jameswattsguitars.com

Here is one I am working on now. X brace with a lattice braced lower bout. This is only the second one I have built this way, but I was very happy with the first, a redwood topped 13fret 000, so I will continue to experiment with it.

Paul

David Schramm has been very helpful when I was asking questions of him regarding the construction details.

Feel free to fire off an email to him, I'm sure that he will receive it well if you are up front about what you are up to. He has more info on his building-course web pages which are not directly available to the general public, but he will send a link.

He, and others, have posted quite a bit about lattice bracing on MIMF.

He typically builds with a 9 brace grid of balsa, about 1/2" high in the bridge area, tapering to almost nothing at the perimeter, and topped with CF set in epoxy. I seem to recall that the grid is based on a 100:80 degree "square", more tall than wide. The rim of the guitar is supported with a significantly shaped 3/4" thick plywood plate.

You're gonna have fun with this one!

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Expectation is the source of all misery; comparison the thief of joy.
http://redrivercanoe.ca/

Thanks all. More is welcome.

My first reaction when someone says, "Finite Element Analysis" is to feel inadequate to the job. My second reaction is that this sounds kind of limited--why didn't you go all the way and do the infinite element analysis?

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

Howard,

Ervin Somogyi does lattice braced steel strings, in fact there was once an image of his lattice bracing post for all to see here at the OLF for a short while. If that guitar were to create just a fraction of the feather ruffling energy which that image did before it was removed, I would suggest it would indeed have great volume and projection.

Cheers

Kim

Hey Jim, cool concept! May I ask what your design criteria was? Were you designing for a specific deflection range or were you looking more at the stresses?

.050 is frighteningly thin....wondering what FEA told you that gave you confidence in this part of the design...? I guess maybe the lattice supports a super thin top better than traditional bracing would...maybe this is it?

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http://www.PeakeGuitars.com

Parser, There's the rub, what's the ideal top look like under analysis. More generally, what's an ideal top anyway?
I started by modeling one of my conventional guitars and comparing actual deflections of it under string load to the FEA model. I used this as a validation step and also to get a feel for what reasonable deflections were on a conventional guitar. I then used this model as a "guideline" for the lattice braced guitar. BTW, I knew the Modulus for the top materials of the particular guitar I was testing from my previous deflection testing, so everything matched up nicely.
In the model I looked at both stress, deflection and also nodal patterns. Honestly though, I paid the most amount of attention to the deflections unless the stress got out of control.
The lattice does carry the loads better than a standard X braced model. Thin tops require that you beef up the sound hole area, hence the transverse brace below the sound hole.
My real complaint with this design is the .05 top. It takes the loads just fine, but I worry about it's robustness to humidity, bangs and crashes.
I had this top on for about 7 months, it's off now and different design is now on.

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Jim Watts
http://jameswattsguitars.com

Jim,

I like your design. Looks a lot like a classical I would maybe move the central bar closer to the hole, and lose the UTB scallops.
The fact that you only beef up near the bridge is fine, makes for a looser rim and allows you to have the top reasonably thick - at .05 in spruce it is not really that scary thin. A Smallman is half as thin, in cedar! But the tone is...hmm hmm...let's just say I don't like it.

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Build log

Here are a couple of guidelines from David Schramm:

"For a Cedar lattice top anything more than 1.5mm is way too thick. A cedar 9x9 lattice with dimensions of 3mm wide x 8mm-12mm max high is plenty strong. You will be surprised how stiff this is. 4mm wide is too wide IMO. I use epoxy to attach the lattice.
When the lattice top is glued to the sides you will start to hear it ring, or should I say a nice pitched percussive thud. I've built 20+ lattice guitars. You can't think like a fan braced guitar maker. Make the back and sides thick! I recommend 3-3.5mm for the sides and 7-8mm thick for the back. Build an "A" shaped frame with the tip of the "A" pointing towards the tail block. The horizontal line goes from one side to the other slightly behind the bridge location. I also recommend that your bridge be about 11-14 grams. 1/4" high x 6 1/4" long and 1 1/8" wide. The string height should be about 8-8.5mm from the top of the soundboard to the bottom of the string at the saddle location. These specs will produce a very powerful lattice guitar with a great tone.
Keep in mind that the lattice design is for tone NOT volume. Volume is secondary to the design, but seems to be the thing that people talk about the most. G.Smallman hates that and I do not blame him."

One of these days I'm going to try one, but I've other projects ahead of lattice. I'm trying to really get a handle on Torres before I move on.

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Expectation is the source of all misery; comparison the thief of joy.
http://redrivercanoe.ca/

I'll come of of lurk mode with what I can add. Lattice bracing will add a lot of stiffness to a soundboard. Adding CF strips top and bottom to the lattice adds a lot more stiffness. This works with the thin, cedar Smallman classical soundboard to get the treble response, but is going to be overkill to a steel string soundboard where the treble will be there anyway. Quite a few people out here on the far side of the world have tried lattice braced steel strings, and I think have almost always gone with an all-wood lattice. The height and doming of the lattice is the critical aspect, whether all-wood or CF re-enforced, rather than the angle. All wood lattices can be made in different ways. They can be all lapped joints (a lot of work), using different height strips in different directions (10mm in one direction and 6mm in the other, so only the 10mm strips need to have notches cut) or continuous strips in one direction and short strips the same height cut to fit in between (which doesn't require any notching at all and can be done surprisingly quickly) Not having the lattice in continuous strips doesn't seem to make any difference to how it works.

One thing that does have to be kept in mind is what to do with the bridge. If a usual pin bridge design is used then a bridge plate that will interrupt the lattice has to be included, other wise some pinless bridge (with the complications that might entail) has to be used.

A good starting point for an all wood lattice would be 10mm x 3mm strips placed 40-50mm apart in a square lattice using a soundboard around 2mm thick. That basic structure can then be lowered and domed as you feel appropriate and thwe soundboard thinned out a little around the edges of the lower bout. It is all too easy to get an overly stiff soundboardand it can end up more like a banjo that a guitar.

What a lattice bracing does give is a very fast attack to the sound and very distinct separation between the notes. Jim Williams built a 12 string many years ago using the two height lattice and that was as loud a guitar as I have heard with quite incredible clarity between the strings rather than the usual big blurry swoosh of a 12 string. That guitar sent me on the track of using the lattice for the bouzoukis.

Hope that helps a little

cheers

graham

Great thread, really nice to see some inventive stuff going on.

Jim, that sounds like a great approach. I've done some similar work....did you take into account creep? I've read that for structural woods creep can result in as much as 150% of the initial strain levels. It would be great to do some testing and see where well seasoned spruce is...I'm guessing it doesn't move this much...but maybe it does?

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http://www.PeakeGuitars.com

Hey Graham,
Nice seeing you here, it was pleasure meeting you at the GAL conference earlier this year.
Like Graham said adding height to the lattice is by far the biggest effect, and I might also add that this is very, very touchy. You can go from the compliance your looking for to way too stiff by being just a touch off. That's one thing I learned from the analysis models. I took great acre in making my top like the model.
I didn't have any problems with overly bright trebles or banjo sounding, probably because I designed it to similar defelections to a traditional guitar. It would be very easy to make this over stiff BTW.
If I were to explorer this more I would probably make a thicker top and lighter braces to compensate.
Parser, I didn't have any creep figures to go by. That's good information, is it from a reliable source?

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Jim Watts
http://jameswattsguitars.com

Howard,
My last 10 have been lattice braced. I am able to use a much thinner top by making a larger bridge plate and adding 2 crossing braces behind the X brace. I make them split up the area behind the X brace. Just tap tune it like normal, but forget about scalloping. Fast attack and great note separation describes it well. It seems to work great for Adi and other spruces, but I'm not sold on it for cedar and redwood. Its not bat for those woods, but I'm not convinced that it is better, like I am for spruce.

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"An adventure is only an inconvenience rightly considered. An inconvenience is an adventure wrongly considered." G. K. Chesterton.

Howard, you might try to get ahold of Richard Prenkert from the Santa Rosa area. His classical guitars are lattice braced and he's been talking about doing a steel string guitar.

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Ken Franklin
clumsy yet persistent
https://www.kenfranklinukulele.com

This is the only place I have found it addressed, although I am sure the info is in some books that I don't have. I should setup a basic creep test on some spruce...should be easy enough to do....just leave it setup in the corner for a couple years...

http://www.awc.org/wood-design/2006/07/ ... ss-it.html

Here's a quote from the site above:

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http://www.PeakeGuitars.com

I am not sure if this is the same kind of creep, but it think it is something similar. (hope I'm not going off on a tangent here)

Smallman's approach to testing the tops was to measure where the first few top resonances were, rather than Jim's deflection testing (Hi, Jim), though I don't know how he is currently doing it. In the early days it was finding the resonances with some sawdust and hitting the strings hard until he found the fretted notes where the sawdust bounced. If those resonances were right on a note, he would shift them a little by supergluing a little block of wood to the lattice, so the resonances fell between notes. Quite astonishing to watch.

As his testing became more sophisticated he discovered that one or more of the soundboard resonances would be different whether the guitar was strung up or not. The compression of the soundboard by string tension between the bridge and the soundhole would cause a shift in the soundboard resonances and he had a work out a way of compensating for this while bracing the soundboard. One way (from memory) was to build in a slight dome in front of the bridge, which would flatten out under string tension. This is on a cedar sound board, probably a little over 1mm thick in that area, and they can be scarily fragile in some ways and repairs sometimes totally impractical.

The lattice bracing concept has opened up a lot of thinking about how guitars work. There are people out here who are taking varied and divergent paths. Lattices that run up and across the soundboard, rather than angled (have a look at Graham Caldersmith's website), various radial bracing patterns, mostly with CF re-enforcements and some even more wayout ideas.

cheers

graham

I use lettuce bracing on all my hamburgers. Oh wait, you said lattice.

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Mike

"The Dude abides. I don't know about you but I take comfort in that. It's good knowin' he's out there. The Dude. Takin' 'er easy for all us sinners. Shoosh." The Stranger