What happens to all the beginner luthier guitars?

[charles Tauber]

Originally Posted by packocrayons

I just saw this and am concerned about my first build - Does the truss rod not go into a straight channel between the neck and the fingerboard? What's supposed to be curved?

“Single action Gibson style” rods, as described by HarryQ, require curved channels . Other types of rods are installed in straight channels.

[packocrayons]

Originally Posted by charles Tauber

“Single action Gibson style” rods, as described by HarryQ, require curved channels . Other types of rods are installed in straight channels.

Phew, thanks for clearing that up.

My first guitar is still on the shop, as you can tell

[murrmac123]

Originally Posted by charles Tauber

“Single action Gibson style” rods, as described by HarryQ, require curved channels . Other types of rods are installed in straight channels.

I know that the commonly accepted wisdom is that a single action compression rod should be installed in a curved channel, but I just wonder whether this is actually necessary, or whether everybody plays "follow my leader".

The neutral axis on the average guitar neck is just underneath the fretboard, and intuitively it would seem to me that a straight compression trussrod in a straight channel, located as far under the neutral axis as possible, would be perfectly able to exert the compression required to counteract the string tension.

If I may give a somewhat more lowly analogy, if you take a length of 2x4" and clamp one edge longitudinally between the jaws of a sash clamp, you will see that the timber will immediately deform in a convexity, bending away from the clamp. If you then apply another sash clamp on the opposite edge, the compression exerted by the second clamp counteracts the bending force of the first, and the timber is pulled straight (always assuming that not enough force is exerted to bring the Eulers Column thing into play)

This is analogous to the tension from the strings being counteracted by the compression from the trussrod.

[charles Tauber]

Originally Posted by murrmac123

I know that the commonly accepted wisdom is that a single action compression rod should be installed in a curved channel, but I just wonder whether this is actually necessary, or whether everybody plays "follow my leader".

My understanding of how a single action, single rod works is that it needs to be curved. Tightening the nut on the curved rod attempts to straighten it, producing the desired effect on the neck. If the rod is straight to begin with, tightening the nut simply attempts to stretch the rod. In that case, either the threads on the nut or rod strip, the rod breaks or the wood against which the nut/washer sits crushes, whichever is weakest.

I've installed only one such rod and that was many years ago. I wouldn't consider that design on an instrument of my own construction.

[Rodger Knox]

Originally Posted by murrmac123

I know that the commonly accepted wisdom is that a single action compression rod should be installed in a curved channel, but I just wonder whether this is actually necessary, or whether everybody plays "follow my leader".

The neutral axis on the average guitar neck is just underneath the fretboard, and intuitively it would seem to me that a straight compression trussrod in a straight channel, located as far under the neutral axis as possible, would be perfectly able to exert the compression required to counteract the string tension.

This is analogous to the tension from the strings being counteracted by the compression from the trussrod.

Originally Posted by charles Tauber

My understanding of how a single action, single rod works is that it needs to be curved. Tightening the nut on the curved rod attempts to straighten it, producing the desired effect on the neck. If the rod is straight to begin with, tightening the nut simply attempts to stretch the rod. In that case, either the threads on the nut or rod strip, the rod breaks or the wood against which the nut/washer sits crushes, whichever is weakest.

I've installed only one such rod and that was many years ago. I wouldn't consider that design on an instrument of my own construction.

In theory, murrmac is correct, a straight channel SHOULD be able to counteract the pull of the strings. In practice, the contact area where the tension in the rod is transferred to compression in the wood is quite small, so the stress can be quite high, close to compression failure in the wood.

For this type of rod to work reliably, it needs the extra help a curved channel provides. It may also need a little help from blocks and clamps when it needs to be tightened.

[Howard Klepper]

Originally Posted by HarryQ

I'm a repairman, and sometimes I buy well built guitars by unknown builders needing work. One in particular was a cedar and rosewood SJ-style with just beautiful and meticulous workmanship. The neck was bowed, and the truss rod did nothing. I removed the fingerboard and found that the single action Gibson-style rod was installed with absolutely no curve, and could not possibly work. I installed a dual action rod, and it turned out to be a fine guitar. How someone can make such a fine instrument without learning how a truss rod works is a real mystery to me!

That kind of rod does not need a curve to work (but it helps). It only needs to lie below the neutral axis of the neck. It works by countering the tension of the strings. Murray has it right.

[HarryQ]

Originally Posted by Howard Klepper

That kind of rod does not need a curve to work (but it helps). It only needs to lie below the neutral axis of the neck. It works by countering the tension of the strings. Murray has it right.

You might be right, Howard. The rod in that guitar may not have been deep enough. It would do absolutely nothing when tightened but begin to crush the wood under the washer, even when clamped into a back bow first. I would never use that type of rod, even set deeper into the neck. I just don't see the need to make the rod work that hard.

[mirwa]

Single action truss rods need to sit low in the neck typically on an angle or laid into a curve within the neck.

We are not trying to compress the wood like a clamp on a bench, we are trussing the headstock / nut area.

I make my own truss rods and personally steer clear of single action models.

Steve

[Rodger Knox]

Originally Posted by mirwa

Single action truss rods need to sit low in the neck typically on an angle or laid into a curve within the neck.

We are not trying to compress the wood like a clamp on a bench, we are trussing the headstock / nut area.

I make my own truss rods and personally steer clear of single action models.

Steve

Without a curved channel, the rod works by compressing the wood in the back of the neck, making it shorter. That reduces the curvature from the tension of the strings making the top of the neck shorter.

An important point is that all these stresses are well below the elastic limit, which means there is no permanent deformation.

[mirwa]

Yes, I think we are talking about the same thing, a single action truss rod will work better in a curved channel rather than a straight channel. It must work as a truss not a compression clamp, so the depth and angle must be significant enough to allow this to happen.

Triangular shapes in constructions are one of the strongest designs you can have when trussing a point.

Sitting a threaded rod just below the neutral axis referenced from string tension, means it will effectively be working as a compression clamp rather than a truss, the lower you can get it into the neck the more effective it becomes as a support beam (for straight cut channels), In a curved channel it becomes a one way adjustable truss as the added tension from winding the nut on wants to straighten the rod out in the curved channel

Steve

[ruby50]

Brian May, guitarist for Queen, made one guitar with his dad in the early 70's. It is the only guitar he ever made and it is still his main guitar. He has had luthiers copy it for backups, but as of about 4 years ago he had not changed the frets yet - said he paid 3¢ a foot for the fret wire. I always wondered why that guitar did not look like any other.

I think he gets the prize for most-used first guitar.

Ed

[murrmac123]

Originally Posted by Rodger Knox

Without a curved channel, the rod works by compressing the wood in the back of the neck, making it shorter. That reduces the curvature from the tension of the strings making the top of the neck shorter.

Not sure about that , Rodger.

If you compress a flexible steel bar, for example, you put the convex side into tension, and the concave side into compression, but there is no dimensional change.

Same with a guitar neck IMO.

[JDaniel]

Originally Posted by ruby50

Brian May, guitarist for Queen, made one guitar with his dad in the early 70's. It is the only guitar he ever made and it is still his main guitar. He has had luthiers copy it for backups, but as of about 4 years ago he had not changed the frets yet - said he paid 3¢ a foot for the fret wire. I always wondered why that guitar did not look like any other.

I think he gets the prize for most-used first guitar.

Ed

I gotta check that out...

I almost feel bad bringing a post aligned with the OP's subject on disposition of first guitars, but it is an interesting thread (the truss discussion is interesting, too). All that exists of my first guitar is a photo and that was the best possible outcome for it. My second guitar finished in 1975 is my daily player and will be until I depart this life. It deserves to be in a study collection as an example of how to break an incalculable number of guitar-making rules.

[redir]

Guild made a Brian May guitar for a while, maybe they still do IDK. It was a very cool guitar too with all kinds of hot rodded electronics. In fact May has other custom made guitars like the one he build but he always uses his own. Cool story. And of course Dr. May is a one of a kind too.

[jazzer57]

No need for me to get into the truss rod conversation. My #1 and #2 have no TR but they do have aluminum bars inside as traditional construction for Gypsies dictate.

Building guitars: What a wonderful and humbling hobby! And, full of super talented and sharing builder companions out there. My thanks goes out to each one of you!

I originally began building as a means to get a better guitar because the good ones were so pricey and I was willing to have a new hobby to take into my retirement years. With so many awesome guitars out there to use as inspiration I figured this would be a cool way to 'try my hand' sort of speak. It is so much more than that. For me, every step is an adventure which needs a new skill or jig or tool and I haven't even gotten to the finishing part (French Polish for me) which is yet another learning experience. I'm thankful that each one is better than the last and I only have two with strings on them so far. I have a lot of bodies and necks and plenty of parts to put together. I would say that #1 and 2 will stay in the family but do I dream of selling some of these? Of course! The reality will be that I'll put a few of them into some local player's hands and hope for the best outcome. After all, it's all about the music,,,right?
Regards Everyone!