Baritone guitar truss rod length?

[Condorfious]

Hi all, I'm making a multi-scale (28"-25.5") 8 string guitar and I'm not sure what size truss rod I should get.

I've been told a "standard 18 inch" will do but I think the whole fretboard needs to have the rod under it (Measuring it comes up an inch or so short)

It's of neck-thru body construction if that influences anything

Does the truss rod need to span the length of the fretboard? Or would it be adequate to run the length from the nut to say, the 21st fret? (I'm doing 24 frets, 7th is parallel)

Thanks in advance

 

[adam.beauchene]

Cool, I'm working on a similarly-scaled instrument.

Will the 18" truss rod make it down into the heel? That's what I always shoot for.

 

[Condorfious]

Not sure what would constitute a heel on a neck-thru. I'm not sure if it spans the length of the fretboard or not hahaha

 

[headlikeahole]

If you're only an inch away from the end of the fretboard thats no problem

 

[adam.beauchene]

Not sure what would constitute a heel on a neck-thru. I'm not sure if it spans the length of the fretboard or not hahaha

The part where the neck turns into the body is the heel.

 

[HaMMerHeD]

The fingerboard doesn't necessarily need to be the entire length of the fingerboard. The 18" rod will be fine. If it really bothered me, I would order a 19" custom length double-action truss rod from LMI, as they do custom length rods for no extra charge.