Conical Fingerboards

[lacrombie]

Hi Trevor,

I want to make a guitar with a compound radius fingerboard. I am in the process of designing a jig to produce said fingerboards - is the compound radius projected over the scale length of the guitar or the length or the fingerboard to a particular fret?

Thanks

[kiwigeo]

This may help:

http://www.stewmac.com/freeinfo/Neck_re ... adius.html

[Trevor Gore]

As per Martin's reply, above.

A few more things to think about though:

1) Once above about 16" fretboard radius, the difference between compound (based on conical sections and string spreads) and cylindrical is generally smaller than the building tolerance that most people can achieve

2) The conical geometry that I discuss in the book, Appendix II-3 (discussed in much the same way as Stewmac explains it) assumes zero neck relief. There is nearly always some relief and the amount is often larger than the build tolerances discussed above.

3) When I've built conical fretboards (and cylindrical ones, for that matter) for the way I play, I need a bit more action on the 3rd and 4th strings than a "straight line" increase in action from 1st to 6th string. The effect of this is that I prefer the saddle radius to be smaller than the fretboard radius to give the extra "lift" on the 3rd and 4th strings. So, for me, the saddle radius is often close to the 12th fret radius on a compound board.