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John Bertotti
Sep-26-2004, 6:19am
Well it's in the works a octave mandola-ish kit from Don aka Luthier. He is knocking off the first two frets on the finger board of his Octave mandolin kit for me and leaving the head stock longer so I can attempt a five course instrument. I need to decide on a nut width. It will be tuned GDAEA with an actual scale length of 20.379.

I would like some opinions on how close the individual courses can be with out a problem Ie.. G to G space D to D space etc. And how close he actual courses can be and still be of an ease to use Ie.. G to D space etc.

My vega is as follows nut width is 27 mm, ( all of these measurements are from the inside edge to inside edge of the strings ) G to G is 1.5 mm, G to D is just shy of 4 mm, D to D is 1.5 mm, D to A is 4.75 mm,
A to A is 2 mm, A to E 4.5 mm, E to E is 1.5 mm with couple of mm out on either side.

I'd like consistency across the board so in combined experience of the Builders here does 1.5 mm sound reasonable for all #
string spacings and 4.5 for all course spacing? For a total nut width of say 36.5 mm. I'd actually like a little extra meat outside the strings ( at the edges of the fret board ).

I see Sobell builds his 10 string cittern at 42 mm nut width.
Fylde's Touchstone Octave is a 8 string at 38 mm.
I may have to rethink the above #s.
I haven't taken into account the movement of an octave at the center of it's string length. Is it going to move farther? If so I'll need to widen the string spacings. I'm now leaning towards the 42 mm nut width. I think my course widths are ok but think I'm to close on the string spacings especially the G and D. Thanks for the input.
Thanks all John http://www.mandolincafe.net/iB_html/non-cgi/emoticons/rock.gif

sunburst
Sep-27-2004, 5:43am
Lots of question and I don't know the answeres.

Here are some guidlines that I hope will help.

I think you'll have to decide on your nut width first, then decide how far inboard you want the strings on each edge, then figure the spacings mathematically.
You could run into problems with the unisons buzzing against one another if they are too close together, and as the string diameter gets bigger as you go toward the bass side, you'll probably need more spacing in general.

John Bertotti
Sep-27-2004, 6:05am
Thanks Sunburst, That is just what I've done. After much internet searching and discussions I decided on 1 5/8 inch his seems good and If I don't like it I can trim it up. I'll probably carve a couple wood nuts with different spacings just to see how they feel and fit and once the choice is made put in the good nut. Have a great week, John