Bowlback Mandolin Help

[Jairo Ramos]

My bowlback mandolin came with a very cheap bridge and a plastic nut. I changed the nut with a bone one, and now I bought a rosewood german bridge with bone insert.

The old bridge came with a strings spread of 36.5 mm, 8mm of separation and 3.5mm for the G, and the others 3mm. In Dave Hynds Mandolin Luthier site 36.5 is the strings spread of Puglisi Neapolitan mandolin, but the strings separation is very different, 9mm, 8.5mm, 7mm, etc. My question is, is a fellow forum member can help me and advice me, if I must to use the old strings separation or the separation suggested in Dave Hynds site in the new bridge.

I noted too that my nut is 27mm, and the puglisi mandolin is 28mm, but the 12 fret widths are the same, 37mm. I used too the method Dave Hynds suggests to calculate the strings spread, and my results are 44mm, very different of the spread in the old bridge. The question would be, If I use the 44mm spread, which is the optimal strings separation for this new measure? and ¿do I must to use 36.5mm or the new 44mm?

Thanks in advance!!

[minuteman]

I just measured my Eastman bowl back.

The spread at the bridge (outside of all strings) is 1.784" or 45.31mm.
The 12th fret (outside the fretboard) is 1.550" or 39.37mm.
The nut width (outside to outside) is 1.04" or 26.41mm.

My Suzuki No.45 bowlback measures as follows...

The spread at the bridge (outside of all strings) is 1.628" or 41.35mm.
The 12th fret (outside the fretboard) is 1.576" or 40.03mm.
The nut width (outside to outside) is 1.078" or 27.38mm.

Some mandolin necks have a steeper angle from nut to bridge. the Eastman has a smaller nut width but a larger bridge spacing. I can switch between the two and can't tell a difference. I never would have noticed if your post wouldn't have nudged me to measure them.

Hope that helps.

[Tavy]

The short answer is that you can use whatever spacing you want!

Normally I choose a spacing that will keep the strings a reasonably consistent distance from the fretboard edges.

[Jairo Ramos]

Thanks minuteman, Tavy!!

I was confused, I thought that the strings spread had a strong relation with the instrument intonation, therefore, I was scared with the bridge slots measurements...

Tavy, you are an expert, your answer clears all to me, thanks!!