Narrow Body Acoustic Bracing Patter

[luke_lee]

I have been asked to make an acoustic guitar similar to the Ian Anderson model by Brooks guitars.
It will have steel strings with a 622mm (approx 24.4") scale length. It has a very narrow body only 246mm at the lower bout and would like your thoughts on a suitable bracing pattern.
I normally use a X-brace pattern with a 100 degree angle but this does not sit well in the narrow body. Any Ideas?

Thanks Luke

[GregL]

Hi Luke,

I like Ian Andersons acoustic guitar playing (Aqualung-era early 1970's). From memory he played very old Martins, so maybe look there for some inspiration (eg ladder bracing near the bottom of this page:

http://theunofficialmartinguitarforum.y ... XfTxkZ25uo

Also Bob Connor has made at least one Terz-size guitar (yours is even smaller than a Terz) - try:

viewtopic.php?t=2867

for some terz talk.

Thanks,
GregL.

[GregL]

Oops I forgot to hit "Preview"! Proper addresses:

http://theunofficialmartinguitarforum.yuku.com
/topic/154134/
Featherweight-Champion-1919-Martin-Ditson-34-Size-Terz#.VXfTxkZ25uo

http://www.anzlf.com
/viewtopic.php?t=2867

GregL.

[Nick]

I'd be thinking about ladder bracing as a 'conventional' route or maybe lattice as something different. Bob builds some great lattice braced guitars so he may add some useful thoughts for you. Falcate may even be a solution too?

[Bob Connor]

For something that narrow I'd be inclined to ladder brace it.

Regards

[Bob Connor]

Or x-brace it like in your diagram.

Put in a very fine finger brace either side.

And a wide (50mm) bridge plate with no other bracing in the lower bout.

Your aim would be to stop the bridge rotating too much by having the bulk of the bridge plate behind the bridge (toward the end block) and placing the finger braces prevent the same. Your treatment of the x-braces in the lower bout

If I read your plan correctly this instrument is 249mm wide at the lower bout. It's very narrow so I would thickness an average Sitka top to somewhere between 2mm and 2.2mm.

The gauge of steel strings will influence things but I doubt whether you'd string anything up with lighter than .011-.050.

I think it would be easy to overbuild something this small.

Regards

[kiwigeo]

Falcate bracing also an option...see my current parlour build. It has a Lutz top and scale length is 618mm. A Gore style CF reinforced bridge plate and the primary falcate braces that pass over the bridge plate will help minimize bridge rotation.

viewtopic.php?f=1&t=6821

[Dave M]

Luke

I have met the guys at Brook and they are a really nice bunch. Given that you are hardly competing with them from Sidney it may be that if you asked they might let you know how they built that guitar.

Dave M from green and pleasant Somerset UK