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Amateur builder here working on #9

I like a 1-3/4" nut width and so far I have been copying my '74 Martin 000-28 making my fretboards 2-1/4" at the body. I have seen other combinations that tell me this is a moving target sort of thing. What do most of you like for this dimension at the body? Is it just a matter of opening up the strings a bit, or are there other reasons to pick a dimension?

Ed

Generally the neck is tapered on fretted instruments so as the frets get closer together the neck gets wider. The space you lose in one dimension you gain back a little in the other.
I like 1 7/8 inch wide nuts, so I use 2 3/8ths neck width at the body which gives 2 3/8ths string spacing at the bridge. For finger picking I like the extra width at both the nut and bridge.
The taper you choose is somewhat of a personal thing, but following the general guidelines of what has been done before keeps you in the realm of what most people find acceptable.

I always figured that dimension based off the width of my string spacing at the bridge.... Maybe I've been doing it wrong all these decades.

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"Act your age, not your shoe size" - Prince

actually your off a tad
here is the martin specs
Nut width 1 11/16 1 3/4
width at 12th fret 2 1/8 2 1/4 ( post 1939)
2 3/16 2 5/16 ( pre 1939 )


the necks were wider in the older days the string spacing on the bridge usually matches the 12th fret.
All of martin specs are based off nut and 12 fret widths

the newer line is a bit different with the 2 1/8 spacing on the 12th fret and 2 3/16 at the bridge on a 1 3/4 nut
You can go on the website and get the specifics for each model . They modern specs are changed from the vintage specs.
Ever what was out there a few years ago. They went with the wider nut and more narrow bridge.

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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

If loving this method is wrong, I don't wanna be right. I'm with Chris. I derive the width of the neck at the neck/body joint by determining the string spacing at the nut and at the bridge, then drawing it all out on paper, including the desired amount of extra neck width outboard of the two E strings. This was what the Cumpiano/Natelson book taught me, and I still do it this way.

I have always followed the width at 12 equals string spacing at the bridge. That was taught at the Fox course.

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It's not what you don't know that hurts you, it's what you do know that's wrong.

Sounds like a chicken-and-egg situation. So how/why do you determine the spacing at the bridge? What goes into the decision? What felt good in the past? Fretting in the high register for the left hand or spacing for the right hand? Ratio of finger width to length? Color of socks while playing?

Ed

All of the above....
The earlier Martin steel string guitars came from designs traditional to gut strung instruments that had wider spacing. I think as accompaniment and strumming became more the role of the guitar the narrower spacing gained traction. For "finger style" playing being able to play the notes clearly is easier with a wider spacing at nut and bridge. Narrower spacing may make chording and strumming a little easier. Much of it depends on what the individual prefers so the chick or chicken playing it is probably the most important consideration.

I also use the string spacing.

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Jim Watts
http://jameswattsguitars.com

+1

That what I do too.

point is the Martin spec was asked and I posted that.
there are lots of ways and if you can play the guitar when your done you did good.

_________________
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

Ed, that is really a pretty complex question. What I normally do if its my own design is decide on a nut width that I like and an appropriate spacing at the bridge. I decide how much offset I want from the edge of the fretboard which gives me the string spacing at the nut. I decide if I want the same edge spacing all the way down the board (can't think of any reason not to but I might want a hair more as I go up the neck). I decide on the scale and which fret will be the body joint. With all those things I can lay out the width of the fretboard, and can either calculate or measure the width at the body joint as well as the end of the board.

it is less of a problem on a standard old acoustic but can be very problematic on electric guitars or an acoustic with a cutaway where you want the horn to blend into the neck heel. I am currently building a double neck electric guitar (no comments, please) with different widths for the 6 and 12 string necks including both nut and bridge and the multiple horns all flow into the neck heels (Gibson style heels). The body and necks are all bound and are assemble in pieces - everything needs to mate up when it all comes together. I don't have the option of doing a lot of fitment sanding because of the bindings. Oh, and the necks are set at an angle just to make it a bit more of a challenge.

Of course, these dimensions are all related. Once you’ve made a few decisions, the other dimensions follow. You can copy some well known factory models, or create your own. I find it easiest to work this out on a spreadsheet, together with scale information. The sheet then becomes a valuable reference throughout the build:
https://www.mullinguitars.com/calculating-guitar-fret-spacing-fingerboard-dimensions-and-string-setback.html

From a player’s perspective, the set back of strings from the fingerboard edge along the neck is actually more important than the absolute width of the neck or string spacing. Before I made the spreadsheet, I customized dimensions of a neck, but the string set back up the neck was uncomfortably close. I now use the spreadsheet as a build guide for every instrument I make.


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