Truss Rods

Roland

This discussion was created from comments split from: sc relic junior build for Scott. It’s a fascinating discussion, but was starting to derail the original thread.

Bond123

Let me say from the start I'm not guitar builder yet but I do follow all the posts on the forum about building guitars.

I noticed that when you routed the channel for the truss rod it was a straight channel but slightly deeper at one end.  I'm thinking a straight rod surely can't do anything, I suppose it might do a little bit but not enough to take out any significant front or back bow. I would think if the rod is straight and you tighten the nut all you're doing is trying to compress the rod or the wood and, if you loosen the nut nothing happens anyway as it's not prestressed.

I just can't get my head round that, so I did a bit of research. First port of call Melvin Hiscox’s book, I have a copy of this as I intend to start building guitars when I retire. He does go into some detail on how a truss rod works and how to fit them with a slight curve. He also states if the curve is too shallow the rod is not very effective. He then goes on to say if the curve is too steep the truss rod adjustment can be too much with the slightest turn.  He shows exactly how to make the routing jig with the curve.

 I was a member of the UKGB forum where I remember someone wrote quite a good post on fitting truss rods, can't remember if it was @WezV or @gspbasses, I ‘m sure it never mentioned about routing a straight channel unless it was for a 2 way rod.

I have looked at guitar plans online and the plans I have for a Telecaster and 59 Les Paul all show the truss rod with a curve.  I'm just wondering how your straight rods work when everybody else seems to use a curved rod or a 2 way rod.

 

Danielsguitars

Bond123 said:

Let me say from the start I'm not guitar builder yet but I do follow all the posts on the forum about building guitars.

I noticed that when you routed the channel for the truss rod it was a straight channel but slightly deeper at one end.  I'm thinking a straight rod surely can't do anything, I suppose it might do a little bit but not enough to take out any significant front or back bow. I would think if the rod is straight and you tighten the nut all you're doing is trying to compress the rod or the wood and, if you loosen the nut nothing happens anyway as it's not prestressed.

I just can't get my head round that, so I did a bit of research. First port of call Melvin Hiscox’s book, I have a copy of this as I intend to start building guitars when I retire. He does go into some detail on how a truss rod works and how to fit them with a slight curve. He also states if the curve is too shallow the rod is not very effective. He then goes on to say if the curve is too steep the truss rod adjustment can be too much with the slightest turn.  He shows exactly how to make the routing jig with the curve.

 I was a member of the UKGB forum where I remember someone wrote quite a good post on fitting truss rods, can't remember if it was @WezV or @gspbasses, I ‘m sure it never mentioned about routing a straight channel unless it was for a 2 way rod.

I have looked at guitar plans online and the plans I have for a Telecaster and 59 Les Paul all show the truss rod with a curve.  I'm just wondering how your straight rods work when everybody else seems to use a curved rod or a 2 way rod.

 

The truss rod is a straight compression rod that has been used on all those old 50's guitars and nothing wrong with them, I've been using them for years, after 1960 they went to a curved rod because the necks were made thinner, it's routed at an angle with about 3mm difference from the anchor to the nut it goes up hill, these are not suitable for most peoples set up because of this 

If you’ve read this thread you'll have also seen i pre load the rod before flatting the board again, this now acts a bit like a 2 way, it's not luck or guesswork, these rods have the best tone imo and how someone builds is up to them after they have experimented, i will make a neck with a 2 way but it'll still get a fillet strip then I'll add carbon fibre rods

Traditional fender necks have curved rods too and they work, it's all down to your wood and how that neck is made, they just take much longer than slinging a 2 way rod in, they're easy 

The other thing about 2 way rods is i still never want a rod without suitable tension on it, you can have perfect relief with no tension or hardly any, I've also heard of welds breaking so they're not perfect either, i don't like the fact my fretboard is being pushed either unless you sink it in and put a small filler strip, at least you'll have full glueing surface that way

Hope that helps you figure it out

Bond123

 I did read what you wrote about pre stressing the truss rod several times but still can't get my head round why you would get the fingerboard perfectly flat, tighten the rod so the neck has back bow then re-plane the fingerboard again. That seems an odd thing to do. I thought I had misread or misinterpreted it but clearly not. I looked on YouTube to see if I could find videos showing the fitting of a truss rod. There were lots of them but some of them seem to be so complicated and take so long I'm sure there are better ways of doing it. I didn't see anybody installing a straight compression rod. When I start to make my own necks, I think I shall follow Mr Hiscox's as it does seem very straightforward, quite quick and effective. 

Danielsguitars

Bond123 said:

 I did read what you wrote about pre stressing the truss rod several times but still can't get my head round why you would get the fingerboard perfectly flat, tighten the rod so the neck has back bow then re-plane the fingerboard again. That seems an odd thing to do. I thought I had misread or misinterpreted it but clearly not. I looked on YouTube to see if I could find videos showing the fitting of a truss rod. There were lots of them but some of them seem to be so complicated and take so long I'm sure there are better ways of doing it. I didn't see anybody installing a straight compression rod. When I start to make my own necks, I think I shall follow Mr Hiscox's as it does seem very straightforward, quite quick and effective. 

You do what you want to do, i said these are not quick and easy and there's a reason why people use modern truss rods because they're easy to install

These traditional rods have been used since before the 50's, obviously I've been building for years now and know what i like and the tone etc  

The pre loading is just for my peace of mind, plenty of high end builders use traditional rods and hot hide glue, it's not because they're quick either

my fingerboard is glued on perfectly flat btw, i also use my radius jig which makes them uniform along the length to start with

I went to merton college for 4 years building acoustics, we used titebond and modern one way truss rods so i have experienced that way and transitioned into my method now because i think it's better, there's no right or wrong just individual experiences 

You'll learn what works for you as you go through learning to build guitars, I'd stick to the easy stuff along with modern truss rods, you can always try and build a traditional neck later on 

GoldenEraGuitars

Bond123 said:

 I did read what you wrote several times but still can't get my head round.....

I think I shall follow Mr Hiscox's as it does seem very straightforward, quite quick and effective. 

This is because you haven’t tried to make one yet

Watching videos is one thing. Hands on experience in this field is paramount. You will find your own method once you’ve tried a few from the videos. It may look quick and effective to you on a screen but the reality may be very very different.

poopot

I have to say and defending the use of this style of truss rod, it works faultlessly. 

Used this type of rod on my recent junior build under the watchful eye of Darren. (Mammoth thread here: https://www.thefretboard.co.uk/discussion/139746/q418c-poopot-jnr ) the truss rod works perfectly, you can actually see the relief come in or out with just the smallest of turns... and it’s as stable as anything. Since the first set up, the truss rod has not needed to be adjusted!!!!! For a newly built neck that’s astounding, also that’s with leaving the guitar outside in the baking heat to age the finish and bunging it in a freezer as well!...

By contrast, I grabbed a neck from a builder on this forum that needed so much work doing to it for it to be playable it wasn’t funny!... modern two way truss rod that doesn’t really function as it should (puts more of an “S” shape into the neck when turned in either direction, the fretboard wasn’t level, I even took it to be plekd at which point the frets came loose!!!!

thread here: 
https://www.thefretboard.co.uk/discussion/156382/fixing-a-favourite-pic-heavy


I’ve seen Darren work, I know Darren quite well... perfectionist and ocd don’t even touch what he does to be fair... frustrates the fuck out of me when I want to crack on with using some tools and he’s there finessing something that 99.9% of people won’t bother doing!.


Just one one final word... it’s great to see a builder get the simple things right as well... no pissed dot markers with Darren!

GSPBASSES

@Bond123 Have a read of the link below, it's a great article all about truss rods, written by some very knowledgeable custom builders, with inputs from several manufacturers.

https://www.thegearpage.net/board/index.php?threads/calling-out-to-builders-truss-rods.404471/

Danielsguitars

GSPBASSES said:

@Bond123 Have a read of the link below, it's a great article all about truss rods, written by some very knowledgeable custom builders, with inputs from several manufacturers.

https://www.thegearpage.net/board/index.php?threads/calling-out-to-builders-truss-rods.404471/

If the traditional rods are good enough for people like Damien probett they're good enough for me, he is one of the best in this country imo 

I won't be using a modern rod in the same way when i get round to it as I've said before and I'm not interested in reading about it either, my view is based on building experience, there are lots of ways to build a guitar, I'm not interested in quick and easy

Perhaps i can get on and build these for Scott now, the proof is in the pudding as they say 

Maybe start another thread about truss rods, I'm not saying this again 

poopot

Here’s my junior built with a “straight” vintage type truss rod... I think you’ll all agree it clearly doesn’t work, doesn’t sound nice and is pretty unusable!... 

https://youtu.be/zHP4cC6CI0Y

as a gigging guitarist its important to me that the gear i use doesn't work at all!!!!

Corvus

One thing with the 2-way strip & rod type, if you happen to have had a heavy night and next day install one upside down and have left enough of a key channel, you can pull the bloody thing out. Apparently like. Not that it's happened to me or anything. I read it on the internet, so er, yeah.

Danielsguitars

Corvus said:

One thing with the 2-way strip & rod type, if you happen to have had a heavy night and next day install one upside down and have left enough of a key channel, you can pull the bloody thing out. Apparently like. Not that it's happened to me or anything. I read it on the internet, so er, yeah.

See there's another plus on a traditional one, goes in one way no fuss apart from actually doing it all 

That's great Bill

When i was at college one student left the rod out, mike the tutor was banging it in from the nut end lol

Corvus

That was a very sweary day Darren the relief* was enormous..

*accidental pun, honest!

On which note, I like 'em well enough functionally and don't do traditional stuff so the aesthetics are OK are for me. I make my necks reinforced multi-piece so the rod has an easy old life. As has been said @Bond123 they're super-easy to install (pref right way up tho'), takes one area of complication out of your first go. There's plenty enough work so it's not really ducking out.
MH's book is still great and reliable but there's more than one way to skin cats.

ICBM

Corvus said:

One thing with the 2-way strip & rod type, if you happen to have had a heavy night and next day install one upside down and have left enough of a key channel, you can pull the bloody thing out.

I honestly don't know why more builders - large and small - don't make the rod channel open at the body end. That way it's possible to remove and replace the rod without doing woodwork - even on a traditional rod with an anchor. Rickenbacker do...

There's no reason having an open channel would cause any structural problem. You can even do it on a set-neck guitar if there's a neck pickup cavity - just have a threaded-on anchor which you can undo by pushing the rod into the cavity first, then pull the rod out from the headstock.

maltingsaudio

For no other reason than possibly of interest here is a section of a MIJ 62 Re issue neck 
https://imgur.com/gallery/oXjWN9z

Roland

maltingsaudio

Thank you @Roland ;

GSPBASSES

Corvus said:

One thing with the 2-way strip & rod type, if you happen to have had a heavy night and next day install one upside down and have left enough of a key channel, you can pull the bloody thing out. Apparently like. Not that it's happened to me or anything. I read it on the internet, so er, yeah.

 

Interesting, but most 2 way rods can be put in upside down and still work perfectly, the only difference being to get back Bow you turn the rod anticlockwise, then obviously clockwise to put relief in. Music man use a 2 way rod that you can remove and push back in upside down, not that there is an upside down to rod that works in either way. Stew Mac also sell rods that can be removed and turned over.

 Read of the link below, it's a great article all about truss rods, written by some very knowledgeable custom builders, with inputs from several manufacturers.

https://www.thegearpage.net/board/index.php?threads/calling-out-to-builders-truss-rods.404471/

---

 

Corvus

Thats what made me realise, turning one way had the opposite effect to usual. Worked Ok in that it affected the neck, but it'd annoy me lots forever after so managed to haul it out.

johnP_90

I've not been on the Forum for a while since my Vintage Tele Neck post last year and read this with interest. I started building with 2 way Stewmac "hotrods" on several Tele's and a Blueshawk years ago before building Bill Scheltema's excellent vintage Tele neck jig using single action vintage truss rods that I now use.Having built several Tele's with both one way and 2 way rods over the years and both sounded and worked just fine though I prefer the simplicity and lightness of the vintage style truss.

I have also scratch built a 59 "Burst LP" from a Tom Bartlett plan that uses the 50's style straight or "compression" 3/16" truss rod and this worked just fine also and just needed 1/4 to 1/2 a turn to bring the neck into straight relief.

I have since built a cs-336 and a DC version (the avatar pic above) using shallow curved rod and truss channel using a 50's style long tenon and hardly any difference to the straight compression rod.

One thing I have noticed, my rock maple vintage tele necks need a truss rod tweek about twice year if humidity swings a lot and so do the pair of CS-336 builds using curved rods. The one that has hardly ever need ANY ADJUSTMENT is the 59 LP build using a straight single action rod. The only advantage in a mild curve in the truss rod channel IMHO is that it is easier to adjust and a tad more responsive if it needs a lot of tension.

Having said that a well constructed neck should only need a minimal amount of truss rod tension to combat string tension, the "loading" also contributes to good tone. It is this compression in the straight rod system that makes them sound so good as the best tone of all my builds is the Bartlett plan built LP! It is a tad heavy but has superb tone and hardly ever needs any adjustment after the initial half a turn to tension the rod.- They work!

In short there is no "right or wrong" method and some of the most iconic and most expensive instruments on the planet use the original Gibbo straight compression rod. So long as it is properly executed.

What saddens me and why I seldom bother posting anything nowadays is the opinionated twaddle I read on various Forums on this subject, and others. Usually from people with little or zero experience of actually building anything, or just good old "Trolling" of good workmanship.

Ring any bells anyone? Bond 123?

Tah, John

PS Forgot to add:

The reason the compression rod works, or any "single action" rod, is that the rod sits 1/8" higher in the slot at the nut end than at the neck heel. This gives a mechanical advantage, or "leverage" and causes the neck to bow backwards or down. What is referred to as "backbow" and combats string tension. This is the fundamental reason it works, and a slight curve in the rod is just an elaboration on the theme to make the adjustment smoother and more progressive, but not essential. If the neck is built right it only needs a small amount of tension and this system works very well with minimal tension.

It is the 1/8" difference in relative position, not the curve that makes it work. In factory conditions where little time is taken on the small things like wood selection, getting the channel "on center" and general fit, a curved channel will help, as probably needs a ton of adjustment to make it play properly, overcome bad fretwork, wonky fingerboards and such like!(Grin) Hence Gibbo adopting the curved channel as do most factory guitars nowadays. Its still the same engineering principle at work.

There is also very little chance of the rod rattling in the truss channel if done right and half the weight of a 2 way truss rod, also less wood removed, light and simple and great tone if correctly done. Wots not to like? Just my 10 cents

poopot

GSPBASSES said:

@Bond123 Have a read of the link below, it's a great article all about truss rods, written by some very knowledgeable custom builders, with inputs from several manufacturers.

https://www.thegearpage.net/board/index.php?threads/calling-out-to-builders-truss-rods.404471/

Agreed, it’s a cracking thread. I did note that the original author of that thread posted this comment.

”Just my opinion, but...take heed...

If a truss rod system is designed for, and installed in order to correct for potential backbowing....

A long look needs to be taken at the entire neck design/build schedule.

At this point in time, the "straight neck/backbowed neck under string tension" situation has been solved...without the use of fancy double-acting truss rods.

Something is amiss with the neck build/design if there are any reliability issues along these lines.

IMO, the truss rod should only be designed to modify an existing forward bow of the correct nature, in order to satisfy an artist's setup needs; there should be no need to crank an unruly neck into submission; that NEVER works, for long.

Take my word for it. Stability is a hallmark of a proper neck build/design. You want to modify a good situation, rather than to force a poor situation into being "better"...that NEVER lasts.”


If I’m reading that right (and I’m prolly not eh?) if the neck is designed and built right in the first place there is no need for a two way truss rod?