Relief query

StanleyAccrington

I'm checking the relief on my acoustic. Using the capo on first fret of low E string...fretting the string at the body fret (fret 14 on my guitar) and taking a height reading with a feelers gauge technique. Is relief always checked by using the low E string? Out of curiosity I checked relief height by using the high e string......and it's different!   I have a relief reading of  0.10mm on the low E string but no gap at all on the high e string.  

Andyjr1515

I don't personally use feeler gauges - I look for just-perceptible movement by tapping the string at that mid point.
However, yes - I check the 1st string and the 6th string and set the truss rod based on the smaller gap of the two.

ICBM

I use the G string because it's in the middle of the neck and the easiest to see the gap. I only use the Es if I think there's a problem with a twist. I aim for around half the G string diameter usually, which is quite easy to judge by eye.

I never use gauges or a capo, just fret the string with both hands while holding the guitar normally - this is important, if you do it with the guitar lying on its back the relief will appear less than it really is because the weight of the neck will pull it back slightly.

A very slight twist with more relief on the low E side is ideal, in fact - as long as it's even. It can be caused by the reaction to the truss rod nut being tightened against the washer, if the adjuster is at the head end. With this one I would loosen the rod just enough to get perceptible relief on the high E and see what happens to the low one.

StanleyAccrington

Thanks for the replies and advice. Good news/bad news situation for me then.
Bad news....it looks like my guitar has a twisted neck.
Good news....I still might be able to set it up so as to play half decently.

Roland

The twist is not severe. If you're not happy with it then you could consider re-levelling the fret board as part of a refret.

ICBM

The twist is not only not severe, it's actually *better* than not having a twist, if it's in that direction - it gives slightly more relief on the bass side. What you don't want is either a severe twist, or it being the other way.

Maynehead

You're in luck, you have an "ideal" twist in the neck.

The thicker strings need more relief than the thinner strings. The high E usually needs no relief at all, so your neck fits that perfectly from the sounds of it.

In practice it means you get lower mid-fretboard action on the thinner strings for the same 12th fret action than if your neck had the same relief across the strings.