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Top Bracing, position of
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=22587		 Page 1 of 1
Author:  Dave_E [ Mon Jun 01, 2009 5:21 pm ]
Post subject:  Top Bracing, position of
Hi Everyone,

Most of the plans I've seen for steel strings have your basic X pattern, tone bars etc. What happens when you "shift" things forward or aft? My Martin D18 says it has "scalloped forward shifted bracing". I know what the scalloped is, but the shifting part has me perplexed. How far forward and what did it do for the tone and volume? :?:

Dave
Author:  Hesh [ Mon Jun 01, 2009 5:38 pm ]
Post subject:  Re: Top Bracing, position of
Dave buddy this will hopefully help you out: http://www.stewmac.com/tradesecrets/ts0051_xbraces.hzml?jrl=704&utm_source=newsletter&utm_medium=email&utm_campaign=ts0051&clk=191731
Author:  James W B [ Mon Jun 01, 2009 5:58 pm ]
Post subject:  Re: Top Bracing, position of
Hey Hesh,Thanks for posting this.I might give this a try.Have you tried this yourself? It would be interesting to know how many forumers have done this,and what the results were.
Buddy Skin
Author:  Mark A Thorpe [ Mon Jun 01, 2009 6:00 pm ]
Post subject:  Re: Top Bracing, position of
Hesh that is what I was going to suggest, that's how I build them, wow they sound great and loud the sustain is awesome.
Author:  Mark Groza [ Mon Jun 01, 2009 6:30 pm ]
Post subject:  Re: Top Bracing, position of
I also build mine forward.I get great sustain and some volume increase doing them this way which i like.
Author:  Jeremy Douglas [ Tue Jun 02, 2009 11:19 pm ]
Post subject:  Re: Top Bracing, position of
I believe the 100 deg angle is incorrect, according to John Arnold and others the angle was around 98 degrees on the 'forward shifted' pre-war Martins.
Author:  Mike_P [ Tue Jun 02, 2009 11:41 pm ]
Post subject:  Re: Top Bracing, position of
how would this information be applied generically?

i.e. to a body design that is not a Martin D shape?

the article gives positions relative to the sound hole, but I'm thinking the effects described are because of the position relative to the bridge as it is stated that the bracing was shifted back for structural reasons to do with the 'warping behind the bridge'
Author:  Jeremy Douglas [ Wed Jun 03, 2009 9:06 pm ]
Post subject:  Re: Top Bracing, position of
Mike_P wrote:
how would this information be applied generically?

i.e. to a body design that is not a Martin D shape?

the article gives positions relative to the sound hole, but I'm thinking the effects described are because of the position relative to the bridge as it is stated that the bracing was shifted back for structural reasons to do with the 'warping behind the bridge'


I believe it does differ by body size on Martins. I think the smaller guitars have the X crossing slightly farther away. If you really want to know ask the guys on the UMGF (unofficial Martin guitar forum).
Author:  bluescreek [ Thu Jun 04, 2009 5:55 am ]
Post subject:  Re: Top Bracing, position of
The pre war was on the dred only. It comes to about a 3/8 of an inch shift of the X braces foward toward the sound hole. The X braces in the ones I had my hands on are between 93 and 98 degrees. With the hole center at 6 inches from the 14th fret , the bisect of the angle is about 1 inch below the 4 inch sound hole.
Author:  woody b [ Thu Jun 04, 2009 9:09 pm ]
Post subject:  Re: Top Bracing, position of
Like John said the measurement from the soundhole isn't important. A measurement from the 14th fret (or whatever fret the neck joins the body) is more accurate. I used to think the position and angle were very important but I think now it's all about the where the X-brace runs under the wings of the bridge.
Author:  Mike_P [ Thu Jun 04, 2009 10:03 pm ]
Post subject:  Re: Top Bracing, position of
woody b wrote:
I used to think the position and angle were very important but I think now it's all about the where the X-brace runs under the wings of the bridge.


this is what I was thinking and why I asked for a generic application of this forward shifted X-bracing...it makes some sense that if the bridge is closer to the intersection of the X then the top would be 'stronger' yet at the same time loose volume (energy)...if the bridge is further away from the X then the vibration of the strings as they transfer through the bridge would be vibrating a more 'open' area of the top...I guess I answered my own question there...
Author:  Alan [ Fri Jun 05, 2009 5:18 pm ]
Post subject:  Re: Top Bracing, position of
A question for those that use the forward shifted bracing: Do you leave off the "popsicle" brace? Is there any real advantage/disadvantage in doing so?
Author:  woody b [ Fri Jun 05, 2009 7:52 pm ]
Post subject:  Re: Top Bracing, position of
Alan wrote:
A question for those that use the forward shifted bracing: Do you leave off the "popsicle" brace? Is there any real advantage/disadvantage in doing so?


The "popsicle" brace and forward shifted bracing have nothing to do with one another except with Martins timing. I don't use a "traditional" popsicle brace, reguardless of my other bracing.
Author:  Alan [ Fri Jun 05, 2009 9:28 pm ]
Post subject:  Re: Top Bracing, position of
woody b wrote:
Alan wrote:
A question for those that use the forward shifted bracing: Do you leave off the "popsicle" brace? Is there any real advantage/disadvantage in doing so?


The "popsicle" brace and forward shifted bracing have nothing to do with one another except with Martins timing. I don't use a "traditional" popsicle brace, reguardless of my other bracing.




Thanks Woody. I wasn't trying to say that they were related, only that my understanding is that Martin didn't use it with the forward shifted bracing, so wanted to see if others doing forward shifted bracing used it or not. To me, leaving it off wouldn't seem to have much benefit and I can see that it would add a little added structural integrity to the upper bout area. Just curious about what others did.
Author:  woody b [ Sat Jun 06, 2009 5:46 am ]
Post subject:  Re: Top Bracing, position of
Here's my views on the popsicle brace. Some of the true experts here might say I'm full of mud. If they do believe them, instead of me.

I think some support there is needed. It helps keep the neck block from........rolling in at the top, if that's the right word. It also helps keep the top from spliting along the edges of the fingerboard. I don't think a modern style popsicle brace is what's needed though. The extra length on the ends of the brace are tone suckers. It's not a big difference, but a subtle one. I've removed a few on '70's Martins. To my ears removing it makes strings sound newer longer, if that makes sense. Like I said, I believe something is needed that, but not a modern popsicle brace. I use a spruce block that fits tight between the neck block and upper face brace. It's tapered on the ends, from 2 1/2" to 3". This keeps the "load" on the ends from running with the grain lines on the top. I use a bolted tenon on my fingerboards so it bolts through this piece but I used the same basic "block" when I was still gluing the FB extension down. I hope my explanation of what I use makes sense. I don't have an open box right now to photograph.
Author:  Todd Rose [ Sat Jun 06, 2009 5:50 am ]
Post subject:  Re: Top Bracing, position of
There have been some good discussions about the popsicle brace here. A search in the archives should turn up some helpful info. Personally, I wouldn't eliminate it without considering its important function of greatly reducing the chance of soundboard splits alongside the FB extension, and doing something else to reinforce that area and serve the same function. That may depend on the type of neck joint and neck block you use.

Posted simultaneously with woody, kinda saying the same thing.
Author:  woody b [ Sat Jun 06, 2009 6:34 am ]
Post subject:  Re: Top Bracing, position of
Todd Rose wrote:
.......................................................................................................
Posted simultaneously with woody, kinda saying the same thing.


Todd, that probably says something about both of us.........but I'm not sure what wow7-eyes
Author:  Alan [ Sat Jun 06, 2009 9:24 am ]
Post subject:  Re: Top Bracing, position of
Todd Rose wrote:
There have been some good discussions about the popsicle brace here. A search in the archives should turn up some helpful info. Personally, I wouldn't eliminate it without considering its important function of greatly reducing the chance of soundboard splits alongside the FB extension, and doing something else to reinforce that area and serve the same function. That may depend on the type of neck joint and neck block you use.

Posted simultaneously with woody, kinda saying the same thing.



Thanks Todd and Woody. I haven't used the forward shifted bracing yet, but plan to give it a try. Your feedback confirms what I thought, so I will retain the brace.
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