Official Luthiers Forum!

Hi I have been thinking of building a guitar similar to the Martin Norman Blake 000 with the 12 fret neck on a 14 fret body. I ordered a top bracing tracing from John Hall and found that the bracing is basically the same as the normal 14 fret 000 with the bridge plate bridge and sound hole moved back. I am a little concerned with the fact that the corners of the bridge barely cross the X brace at the ends, only about 1/2 the bridge ends will be on the brace.

My question, is this enough for strength and sound transfer to the top? will this cause the top to be pulled up too much in the future.

Fred

_________________
Fred Tellier
http://www.fetellierguitars.com
Facebook page http://www.facebook.com/pages/FE-Tellier-Guitars/163451547003866

That was my thoughts also, and even moving the center of the x back a little as it is real close to the sound hole as shown. I am not sure if changing the brace angle and location of the X will cause a change in the sound of the guitar. I am surprised that Martin did it the way that the brace tracing shows as it looks that it could be a problem down the road with top bowing and bridge causing the braces to come loose.

Fred

_________________
Fred Tellier
http://www.fetellierguitars.com
Facebook page http://www.facebook.com/pages/FE-Tellier-Guitars/163451547003866

Fred,
I think you’d be surprised how much wiggle room you have before adversely affecting the tone of the instrument. Your intuition is correct regarding a good overlapping of bridge to x braces but any overlap is better than none I suppose. I like to think the bridge, patch and x braces as one interconnected system. It’s likely a good idea to make that system as tight and strong as possible without building in too much bulk.
Also consider what gauge strings you plan for this instrument. If you want to put on heavy gauge strings, consider an extra cross brace along the back edge of the bridge patch. Many have also used a second x brace at the lower bout instead of tone bar braces to help combat the dreaded humping behind the bridge.

_________________
Wade
Nashua, NH
http://www.wadefx.com

So the bridge ends just cross the X (ie the X comes out the bottom end of the bridge, not the back corner) .. I make mine like that all the time .. plenty of tone transfers. If you think you want more than that, simply make the bridge a bit longer ... dont move the bracing.

_________________
Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

that is fine , that is the way Martin does it.

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

Thanks for the advice John and Tony. I realize this will work, but I was a little nervous with the bridge only crossing the X brace with only 1/2 its width on the corners. I have heard rave reviews on the sound of this configuration and will try it, I am planning a visit to Elderly Instruments next weeks to try one, their web says they have a Mahogany one in the store .

Fred

_________________
Fred Tellier
http://www.fetellierguitars.com
Facebook page http://www.facebook.com/pages/FE-Tellier-Guitars/163451547003866

I am currently building a guitar with a similar configuration - the bridge just barely crossing the X because of a slightly wider angle. I'm looking at it as a hopeful experiment. I didn't realize the NB was like that (he is one of my favorite players).

Fred, I'd be interested in hearing your impressions of the Martin NB.
Walter

_________________
Walter Lay
"It's taken me so long, but now that I know
I can see. All that I do or say, is all I ever will be"
- Billy Joe Shaver

Thanks Tod, what do you think of this layout as far as resisting string tension over the life of the guitar. I think I will build one after my OM size wedge that I have started.

Fred

_________________
Fred Tellier
http://www.fetellierguitars.com
Facebook page http://www.facebook.com/pages/FE-Tellier-Guitars/163451547003866

Fred: If you go to the Unofficial Martin Guitar Forum and look under Technical Info for Martin Bracing Library you will find a ton of pictures showing bracing and line ups of the bridges.Photos taken from outside guitar with light inside the guitar.Interesting and useful data.
Tom.

_________________
A person who has never made a mistake has never made anything!!!

This won't be very useful to you, but I thought I'd comment anyway. I don't build to existing plans or copy other instruments. I design my own. I make the X cross much further in under the bridge than this. My thinking is that, by placing the braces where they are most needed for load bearing, they essentially work more efficiently, so I can make the braces smaller, and they can still carry the load. The end result is a more lightly braced top that nevertheless holds up very well under string tension. I don't have enough guitars under my belt (or enough years on the guitars) to be certain this approach working as well as I think it is, but so far so good.

Todd, from an engineer's standpoint, do you think my logic makes sense, or am I missing something?

_________________
Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/

I have in the past looked at the bracing archive but decided to look again, and it is interesting how much or little of the bridge crosses the X brace, it seems the non D size martins have much less overlap. This along with Tony's post eases my concerns.

I may change the X angle a little bit to bring the lower X closer together under the bridge, or move the X point a little back to get a little more overlap. I am not sure what this will do to the sound of the top.

Fred

_________________
Fred Tellier
http://www.fetellierguitars.com
Facebook page http://www.facebook.com/pages/FE-Tellier-Guitars/163451547003866

Indeed, the proof is in the pudding. Still, I find it helpful to check certain ideas with someone such as yourself with the engineering knowledge to authoritatively state, "Yep, you got that right" or "Actually, no, you're off the mark there". The key sentence in my post above is this:

"...by placing the braces where they are most needed for load bearing, they essentially work more efficiently, so I can make the braces smaller, and they can still carry the load."

Would that statement stand up in the court of engineering?

_________________
Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/

Thanks, Todd. Much appreciated.

_________________
Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/