Movement in Non-Adjustable Neck with Carbon Rod

[hat]

Do you know if it's the neck, or the top that has changed? The first thing I would do is lay a straightedge along the freatboard, one that is long enough to almost touch the bridge. I would want to know if it was neck angle, top bulge,neck relief, or a combination of all three in play. Then I would decide on a course of action. Keep in mind that humidity changes can affect the fretboard as well as the top.

[charles Tauber]

Originally Posted by Bruce Sexauer

Personally, I really like the light weight of a guitar w/o a steel truss rod.

So the issue is weight. What we need to come up with is a light-weight adjustable rod, other than titanium.

[charles Tauber]

Originally Posted by hat

I would want to know if it was neck angle, top bulge,neck relief, or a combination of all three in play..

Neck relief is neck relief: it isn't related, for all practical situations, to neck angle or top bulge. If the neck angle or top bulge were way, WAY, WAY out of typical situations, then, yes, there would be greater bending stresses that would probably increase neck relief.

Neck angle, top bulge and neck relief can all increase string playing height.

[Edgar Poe]

Originally Posted by mirwa

In regards to your specific problem, let me simplify, I will do this with a mathematics example

1=1, if the tension of the strings on the neck equal all factors that give the neck its strength we have a 1 = 1 situation, so the strings are held perfectly the neck maintains the same relief its a 1 = 1 situation.

If we increase the gauge of the strings to a point where the neck can no longer maintain the same relief then we are no longer even and we get excessive relief

Steve

I have long advocated that an increase in string gauge, might increase the possibility of the neck relief changing. Along with that I also included relaxing string tension when a guitar will not be used for a time. The latter has slowly became acceptable. But for some time, it was said by many, that string tension did not play a major role in distortions to a guitar. I disagree.

Ed

[justonwo]

No, it’s the relief. An increase in action is to be expected on a new guitar for the first 1-2 years. Relief is measured independent of action.

[redir]

From what I've read of CF rods in a neck they are almost worthless in terms of structural rigidity unless they are installed very far off the neutral axis.

But I digress

I've built a few and have always used CF bars even though I don't think they work well. It's better then nothing but not as good as most people think...

What I often wonder are things like this, if the rod has any wiggle room what so ever when it is installed then it might give a bit more movement down the road. I've always embedded them in the neck with epoxy. That's probably standard procedure but if they are just laid into a routed out slot like a standard adjustable truss rod then that might cause movement.

That's a lot of movement in a short period of time though. I'd expect to see something like that maybe in the first week or two of the guitars life. So I'd look again into environmental factors?

[mirwa]

Originally Posted by redir

From what I've read of CF rods in a neck they are almost worthless in terms of structural rigidity unless they are installed very far off the neutral axis.

But I digress

I've built a few and have always used CF bars even though I don't think they work well. It's better then nothing but not as good as most people think

Further digression.

I like carbon fibre for fixing necks that have a tendency to twist under tension or that cannot maintain relief, example bass guitar necks and 12 string necks.

Currently this week i have fitted two carbon fibre rods to an old greco bass neck and in the que for next week is an ovation 12 string that will get them as well, so no end of work, however i use them as an accompaniement to the existing adjustable truss rod.

Steve

[mirwa]

Originally Posted by Edgar Poe

I have long advocated that an increase in string gauge, might increase the possibility of the neck relief changing. Along with that I also included relaxing string tension when a guitar will not be used for a time. The latter has slowly became acceptable. But for some time, it was said by many, that string tension did not play a major role in distortions to a guitar. I disagree.

Ed

Ed, you are a hundred percent correct.

Steve

[Quickstep192]

Originally Posted by mirwa

Why in this day and age would someone build a guitar without an adjustable truss rod, defies logic.

Steve

Do you think that’s the case even with classical guitars?

[mirwa]

Originally Posted by Quickstep192

Do you think that’s the case even with classical guitars?

Nope, typically i find necks made for classical guitars are wide and thick enough to resist any movement from the nylon strings.

Steve

[Skarsaune]

I, for one, appreciate the digressions and discussions, because I find them educational.

OP, if you don’t mind, why the preference for a non-adjustable rod? Is it the weight, as an earlier poster mentioned?

[kkrell]

Originally Posted by BT55

The approximate cost of installing a dual truss rod is $500.

Any version of a refret is a band-aid solution but the installation of a dual action truss rod is minimally more but provides a permanent fix.

Speaking of digressions in this thread:

I'm curious about the future, should the steel bar in my 40-year-old ever shift. What's involved to install a dual truss rod in an existing guitar that doesn't have one: Pull frets & fretboard (no fretboard binding), remove current reinforcement, route appropriate channel, provide adjustment hole for truss rod end, re-attach fretboard, adjust, fret, refinish touchup, setup?

[redir]

Originally Posted by kkrell

Speaking of digressions in this thread:

I'm curious about the future, should the steel bar in my 40-year-old ever shift. What's involved to install a dual truss rod in an existing guitar that doesn't have one: Pull frets & fretboard (no fretboard binding), remove current reinforcement, route appropriate channel, provide adjustment hole for truss rod end, re-attach fretboard, adjust, fret, refinish touchup, setup?

Pretty much yeah. You might get away with not having to refret it but I'd probably do that anyway.

[justonwo]

Originally Posted by Skarsaune

I, for one, appreciate the digressions and discussions, because I find them educational.

OP, if you don’t mind, why the preference for a non-adjustable rod? Is it the weight, as an earlier poster mentioned?

Yeah, I don’t mind the digressions. It’s just that very few people actually addressed the questions. Just Charles and Bruce.

Yes, the preference is for the very low weight that comes along with the carbon reinforcement. Once a carbon reinforced neck is stable, it doesn’t need adjustment. Occasionally, you get a headache as in this situation, but for the most part they’re trouble-free. I just really like low weight guitars, and I trust guys like John Slobod, Laurent Brondel, and Howard Klepper to do it right (or make it right if something happens, as in this case).

You can’t even breath the phrase “non adjustable truss rod” without the attending debate about whether it’s an ok thing to do.

[Quickstep192]

You can’t t even breath the phrase “non adjustable truss rod” without the attending debate about whether it’s an ok thing to do.
__________________

The saying I have is “I’d rather have it and not need it than need it and not have it”

Actually, I say that about a lot of stuff.