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I'm drawing up a plan in Autocad for a guitar I'm going to be building for a friend. There are a few dimensions that I'm unsure of related to string spacing and the fretboard dimensions.

This will be a 1-7/8" nut, I'm trying to figure out what an appropriate spacing would be at the bridge. I seem to remember reading a long time ago on some forum that 2-1/4" (center to center of low-E and high-E) was most popular for that nut width. Anyone know for sure? What does Martin use when they use a 1-7/8 nut?

I'm calculating string spacing on the nut using a spreadsheet from the mimf library that figures in the string diameter for equal spacing between the strings.

I'm also curious if the outside edge of the fretboard should be parallel to the outside strings, or should it taper out a bit?

I won't be making the fret board for a while, but I need to know where the edges of the fretboard will be as I design the cutaway.

Not that this matters for my question, but this will be a 12-fret OM (using the 14-fret OM body shape), 25.4 scale, with a florentine (pointed) cutaway. I'm using my Larrivee Pete Anderson as a guide for the bracing and whatnot, as it's a 12-fret with the OM shape.

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Jonathan Kendall, Siloam Springs AR

Here's kind of a rough sketch so far of what I'm working with:

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Jonathan Kendall, Siloam Springs AR

I have only built one guitar with a 1-7/8" nut
It was a loose copy of the Martin D-18s
(12 fret dred)25.4 scale 2-1/4" string spread C-C
Tom

Jon, the spacing at the nut should be according to the players comfort with their left hand. And, the spacing at the bridge should be governed by the way they like to pick the guitar with their right hand (assuming a righty). The two are not necessarily linked or dependent on each other, but should be decided independently. Ask the player what they are comfortable with. Once you have the scale length and those two widths everything follows.

I always have my strings about 3mm from the edge of the fingerboard at the nut but about 4mm at the 12th fret to allow for the greater bending of the string higher up.

Colin

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I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

See Campiano's book for a good coverage of setting out procedure for a
steel string (and classical too).

My steel strings have 3mm between edge of fretboard at nut and 4-5mm
at the body join (14th fret).

I dont enjoy sitting in front of a computer all day so do my guitar layouts
on a sheet of A3 light cardbboard...it makes visualisation easier when
youve got a full scale mock up. The neck layout gets cut out and used as
a template during construction.

I've found that if you use the same width at the 12th as the string spacing at the bridge I am spot on. Because the spacing at the bridge is actually the strings and at the 12th it measures the whole fngerboar, it works out great.

If you make the end of the FB (21st fret) about 5mm wider than the bridge spacing, that will work out as well.

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

    Pwoolson got it right. usually these wider necks havd wider bridges. 1 7/8 is a 12 string width though a few of the old styles did have such a wide neck.
    I use a rule of thumb from Martin on spacing
1 11/16    2 1/8 at the 12th and bridge
1 3/4      2 1/4 at the 12th and bridge
1 13/16    2 5/16 at the 12th and bridge
1 7/8      2 3/8 at the 12th and bridge
   while these are the martin specs feel free to use anyting you want but you do want to keep the spacing at the saddle within the width of the fretboard at the 12 fret for Martinish and width at the body connection for gibsonish
    Also 1/8 is a tad heavy for the spacing of the string. I start them at about .090 ( 3/32 )
john hall

I do it the same as Paul. I will make the width of the pin to pin the same as the fretboard at the
12th fret. I also do as Colin said, build to the preference of the client. My last OM was 1 7/8ths nut and
2 3/8ths pin to pin at the bridge. So to make the fretboard, I first found my center line, then marked the
nut width, then moving up to the 12 fret, I marked out the 2 3/8ths then connected the dots for a proper
fretboard taper. What this does is allows for a bit more wiggle room up the neck where the strings are looser, and
helps to prevent the strings from falling off the edge of the board.
Mark Blanchard actualy gave me this tip while building my 2nd guitar and I have used it on every one since.

Below is a quick and dirty graphic.

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Lance@LuthiersForum.com

Thanks for the tips everyone. i think those Martin specs are what I was looking for. I have a friend with a 12-fret 00-18 that has a 1-7/8 nut, and I just had him measure it at the bridge and he said it was 2-11/32", which is close enough to 2-3/8" for me.

I think you're right (John Hall) about the 1/8" spacing on the outside strings, I thought that looked like a lot of space. I'm going to knock that down to 3/32".

Martin, I agree with you about sitting in front of a computer all day... But I do this fulltime and it's just second nature drawing for me to draw it in cad and doesn't take me very long. I can plot it out on posterboard and cut templates out of that, works out pretty slick.

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Jonathan Kendall, Siloam Springs AR

[QUOTE=letseatpaste]
I think you're right (John Hall) about the 1/8" spacing on the outside strings, I thought that looked like a lot of space. I'm going to knock that down to 3/32".
[/QUOTE]

Hmmm . . . care for a dissenting view?

I see 1/8" as just about the minumum inset. If the player of the instrument likes to do pull-offs, especially with lighter gauge strings, the high E string will have a tendency to slip off the fingerboard during the pull-off, if the string is located too close to the edge. Keep in mind that you'll be putting a bevel on the edge of the fret as well, which will eat up some of this margin.

Best,

Michael

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Live to Play, Play to Live

I got about 1/8 as well, a little closer for the high E, but I agree with Michael, your going to lose some of the space with the bevel of the fret end, that is unless your fret end is blunt.

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Lance@LuthiersForum.com

If I remember right from Harry Fleishman's class, he had suggested making the spacing slightly less on the treble side as it was more comfortable for the player. Or was it a larger spacing on the treble side? Shame on me for not taking better notes. In any case, it would result in an asymmetric fretboard, though it was a small enough difference that noone would be able to tell visually.

I'm all for dissenting views... I'm just going to let everyone argue it out until everyone agrees unanimously, and then I'll do whatever everyone decides.

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Jonathan Kendall, Siloam Springs AR

I'm sure that Harry was recommending slightly more on the treble side. Pull-offs on the 6th string will be pulling the string away from the edge.

On my classicals, which admittedly have more rubber-bandery strings than steel, I inset my high E a minimum of 4mm (~ 9/32") at the nut. I prefer 5mm (~3/16"). On the bass side, I know 4mm is plenty, and sometimes I will squeeze it as shallow as 3mm, but I prefer not to, because with nylon strings, it is not difficult to push them off the fingerboard on the bass side if they're too close to the edge.

Best,

Michael


Best,

Michael

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Live to Play, Play to Live

Michael, I think Joe is right that Harry puts slightly more space on the bass side. I do the same for this reason: I feel it's more natural to tend to push the E string off the edge than pull the e string off. Unless I'm pulling off quite hard, I don't have any problems on the e side but on my older guitars (where both sides were equal) I tend to push the E string off pretty easily. Maybe I just play wierd.

I doubt you play wierd, Paul It could be the reason is more due to playing technique. Classical players use a precision grip with their left hand (ie, they don't "hook" their thumbs around the back of the neck), while most steel string players use a power grip, and hook their thumbs. I can see how, with a power grip, it wouldn't be difficult to push the low E string off the fingerboard when fretting an open G-chord, for example.

I guess this points out the importance of setting up the guitar for a person's playing style, eh?

Best,

Michael
Michael McBroom38899.8842361111

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Live to Play, Play to Live