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I started making the neck for guitar number 2. I don't care for the wide neck i built for #2, so I'd like to change that here. I don't have a modern D28 to measure, and my 1937 plans used a wider neck. Could one of you share the dimensions for nut width and neck at body width?

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Hutch

Get the heck off the couch and go build a guitar!!!!

Found it

The Martin D 28 acoustic guitar is made of solid wood, with East Indian rosewood back and sides, and a Sitka spruce top with 5/16” straight (non-scalloped) braces. It has a mahogany low profile neck with a 1-11/16” width at the nut and 2-1/8” at the 12th fret. The guitar has an ebony fingerboard and bridge, and a bone saddle and nut with 2-1/8” string spacing. It has a scale length of 25.4 inches, which is the standard for dreadnought acoustic guitars.


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Hutch

Get the heck off the couch and go build a guitar!!!!

I think the specs you found are dated. Martin changed the neck/fingerboard dimensions on dreadnoughts some years ago. Just check the Martin website if you’re looking for the modern (in my mind much improved) specs.


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All I can get is the nut width on their site.

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Hutch

Get the heck off the couch and go build a guitar!!!!

I researched neck shapes for months and have an excell spreadsheet with every dimensional detail of every neck that I could find reliable information on. I also bought Martin 000 and D necks from a guy I know that worked at Martin and had cosmetic rejects (knots and deep tool marks).

2006 Martin HD-28 Neck thickness (no fingerboard)
1st Fret: 10th Fret FB Thickness
0.590" 0.626" 0.240" Width of last Fret 2.30

Martin D-28
1st Fret: 10th Fret" FB Thickness
0.580 0.667 .249 FB
Neck Shape: Modified Low Oval; FB @ Nut: 1 3/4''; 2 1/8 @ 12 Fret; Bridge Spacing: 2 5/32"

I posted a pdf of neck shapes a while back. You can cut and paste the profile you want to a pdf file (I attached a 1:1 scale from my printer scaloed at 96%). I printed the Modified Oval file at 96% for it to come out to scale. I glued the paper profiles to a piece of SQUARE plywood for a template and used the osc spindle sander to sand to the middle of the line.

If you scale and print, the profiles have measurements you can verify with a precision scale and, in my case, an optivisor. Modified low oval is the Shape I used. If its not to scale, calculate how far its off and use the print to scale function to scale it 1:1 . THats how I did it.

KEY:
H1 and H2 are called-out/ illustrated on the ..." Technical..." file, attached.

Happy Carving,

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Measure Twice,

Karl Borum

More neck information from Martin that is not enough to carve a neck, but good to build a database with:


https://www.martinguitar.com/blog-categ ... apers.html

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Measure Twice,

Karl Borum

martin has about 27 different neck shapes
here is what you need to know to get into the game.
A nut width
standards for martin are 1 3/4 1 11/16
B they measure the taper at the 12th fret
usually
1 3/4 nut 12th fret can be 2 1/4 modern 2 1/8
1 11/16 nut 2 1/8 at the 12 th fret
I like this profile
thickness at the 1st fret with fret board .800
thickness at the 10 th fret .900

I shape the neck with my fretting hand , after all that is the hand that uses the neck

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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

The dimensions you guys are giving me, are not adding up. If I use the 2 1/8 bridge pin spacing and 2 1/8 width at the 12th fret, I end up wit a fretboard that moves away from the string as you get to the end. My hand drawing and Sketchup drawings tell me I need 2" width at the 12th fret and 2 1/8 at the end of the fretboard.

_________________
Hutch

Get the heck off the couch and go build a guitar!!!!

These are some dimensions i found, plus the ones my brother measured on his Martin.

Martin neck
Nut 1-3/4
12 fret 2-1/8
Bridge 2-1/8

Gary's neck
Nut 1-5/8
12th fret 2-1/16
Bridge 2-5/32

I haven't tried drawing the Martin dimensions yet. I'm not sure if i want to make as tight of a neck as Gary has on his Model special edition SPDC – 16 R.

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Hutch

Get the heck off the couch and go build a guitar!!!!

Load the page for the current model you’re interested in. Go to specs at the bottom of the page. Note the “Load more” button below that to expand the specs. Everything you’ve asked for really is there.


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I've been thinking about this a lot now. I've decided not to copy the SP neck. My thinking is, i like the added space at the nut for clarity. I find i can't get a clean c chord. You know how the first finger wants to mute either the g or e when doing a slow rake.

Im going to follow the modern D28 specs, which maintain the nut spacing I like while reducing the width up the neck compared to the 1937 version that I made.

On to making a fretboard with this in mind.

The other change for this one will be a slotted peghead. I always thought they were more ergonomic and cool looking.

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Hutch

Get the heck off the couch and go build a guitar!!!!

Got it. Thanks

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Hutch

Get the heck off the couch and go build a guitar!!!!

OK, I'm satisfied with this now that I've drawn out the modern fretboard.

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Hutch

Get the heck off the couch and go build a guitar!!!!

Just to clarify: For some designs, having the strings move a bit “inbound” from the edge of the fingerboard as you go up the neck is a feature, not a bug. But you should obviously design it the way you want to. I’ve done it both ways, and both are fine, but it is good to be deliberate about that choice. Some folks get surprised when the spacing in the finished guitar is not what they expected.

Don, getting surprised is why I removed the first bridge and plugged the holes on my #1 guitar.. That'll never happen again. I get to use that bridge on this one, though. Yay, a win.

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Hutch

Get the heck off the couch and go build a guitar!!!!

Back in 2004 at the Fox course we were taught that the spacing at the bridge pins should equal the width at 12. That’s what I have always done.

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

Yep, me too.

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Steve Smith
"Music is what feelings sound like"

Well, im with you fellers.

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Hutch

Get the heck off the couch and go build a guitar!!!!

banjopicks, I know exactly where you're coming from. I've had a bunch of surprises preparing for my current build.

I've spared everyone the full page journey-for-precision I just wrote in reply, but I saved it in case you run into what I did...

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Measure Twice,

Karl Borum

After much experimentation this was the best neck we derived when producing many.

Hope this helps.

Blessings,
kw

Looks like you got it sorted. FWIW, I'm using these dims for the dreds in progress:



I'm using the bridge spacing for D28 of 2 5/32" however my FB is a little wider at 2 1/4" rather than 2 1/8" - https://www.martinguitar.com/guitars/st ... SATIN.html

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I also follow the rule that the neck width at the 12th fret = the string spacing at the bridge. I find this works well for me, but it is true that this results in the strings being non-parallel with the edge of the fretboard. The “extra” board space outside the strings gets slightly greater as you go up the board, or putting it the other way the strings are further from the edge as you go up. I know some very well reputed and experienced builders use a neck dimension where the 12 fret width is a few millimeters (I guess a 16th of an inch) narrower than the spacing at the bridge.