MIMF

I am building an arcthop using the Benedetto plan that has a 1-3/4" nut. Benedetto says in his book that the 12th fret width should be 3/8" wider than the nut width. So for the 1-3/4" nut the 12th fret width would be 2-1/8". If I use a 1-11/16" nut width, does this same rule apply so for a 1-11/16 nut, the 12th fret width would be 2-1/16"?

I've never been able to make any of the rules work for fingerboard width--the rule has to take into account nut width and string spread at the bridge. I have always just drawn out the entire scale length with the outside strings, and then measured a sufficient ledge (I always use 1/8" on both sides) and drawn the edges of the fingerboard. When I'm sure I have the drawing right, I make the fingerboard to match. I have a large piece of poster board that I draw this on. Every time I do a new combination, it goes on the board. I never have to redraw that combination. Drawing can prevent a lot of wood waste.

The rule of thumb is that the fretboard width at the 14th fret matches the string spacing at the bridge. Since I know of nobody that wants a spacing of less than 2-1/8" at the bridge, that's what you'd use for the 14th fret width. If you want to use a 2-1/4 spacing, then make it 2-1/4" wide, etc.... No matter the nut width.

Or you can draw it up, full scale, like Bob suggests, and figure it out that way. But keep in mind that many players don't mind having the strings closer to the fretboard edges at the nut, as this gives them a slightly "roomier" string to string spacing, and at the same time, more space away from the edges as they move up the neck, where it is easier to "pull" a string off the fret's edge.

In other words, most players don't want the fretboard's taper to exactly follow the strings' taper, but actually want a bit -more- fretboard taper. And for this, the rule of thumb works rather well....

Hi Philip, This is the formula I use when I build basses and I use .125 for d - hope this helps...

A appears to be the string spread at the nut, not the nut width which is A+2d. Nonetheless the formula appears to be correct for keeping a constant spacing from the string edge to the fretboard edge.