Truss Rod Preferences?

[thedoctor]

rhoads56, Now this is an opinion-oriented discussion, isn't it? Don't go off the deep end but you do have valuable opinions of your own. Trussrods do twist around the axis of their placement and cause of this, some people hedge their bet with two in certain cases. Warmouth monster plank bass necks have two parallel(spelling?) one-ways to try to control any rotation from the wide spacing of 6 to 12 strings(Iknow, 12 is too many) and I don't think it has any use in a neck that is made of anything but cardboard. The thought of fixing a channelled/boxed rod in exopy or whatever IS counter to common sense and, I'm sure, doesn't help keep a neck in decent playing condition. But people like Fender and Carvin have been putting their necks in compression for years, fully aware that this ruins the sound of certain notes. As Arlo would say, this is a song about notes. I know that there are about 18 ways to skin a cat and only about 10 of them are fun so lets chill and let the other 8 ways be heard. God, I am so full of CRAP!! Forgive, please.

[Setch]

Epoxying the truss rod in to the neck pretty much guarantees it aint going to work efficiently.

Sorry Perry, but this indicates a pretty fundamental misunderstanding of how the Martin style rod works. The U-channel is arched by adjusting the rod, and forces the neck to adopt the same curve. The rod works just as well glued in, and contributes a lot of lightweight stiffness if glued. As most folks know, stiffness is good in necks, helping to prevent deadspots or wolftones. You've been pretty uncompromising about leaving factually inaccurate statements by other users unchallenged, so it seems appropriate to do the same on the rare occasion when you make a totally incorrect statement .

I think the twisting point Catnine raised is pretty much irrelevant, and ignores the simple fact that if a neck want to twist (note: Twist, not bow), it's going to, and there's nothing you can do about it, irrelevant of what type of rod you use.

As for makers using martin style rods, 'Make Your Own Electric Guitar' p.59:

"Another variation on the theme is the system that was used on almost all Japanese guitars for many years. In this case, the rod is fitted not into the neck but into an inverted U-section aluminium channel and it is this channel that is fitted into the neck, just under the fingerboard."

I know my Epi' SG has one, and I imagine it is one of a great, great many produced in that fashion.

[Southpa]

The whole idea of a truss rod is so the neck moves with it when adjusting. So I can't see a problem with mounting a rod with epoxy. Just make sure it isn't embedded in so much that you can't turn it, .

The benefit of the Stew-mac hot-rod is that you can just plunk it in without having to do fancy woodwork to anchor the end blocks. HOWEVER, those end blocks still have to be installed securely with NO room for movement up or down as well as sideways. And you'd better make sure your fingerboard is well glued and the glue is cured. Those rods really like to flex when adjusted. I had a fretboard pop right off one day after a few turns of the truss rod. I guess I was just rushing things.

As far as twisting goes, the only manufacturer I know of that has made a rod that will correct twisting is Rickenbacher. Their rod is a dual style with the two rods side by side rather than on top of each other. That means you can adjust both rods to control neck relief on each side. Hagstrom made a nifty truss rod that has little wings sticking out on either side. That is why they have managed to make the thinnest neck possible (never seen one that is smaller) that maintains its stability.

So if your neck doesn't have a lot of substance and you are using a flimsy single truss rod, then string tension alone would be enough to cause your neck to twist. ie. more tension on the bass side than treble. Other causes are a neck that doesn't have a symmetrical profile, uncured neck wood (ouch!) that is still moving, a truss rod that has not been properly centered (of course) and using wood that has has not been quartersawn. We all know that extreme, rapid temp and humidity conditions can do some nasty things. If my neck wood decides to move around a bit then I would prefer that it moves evenly. Its all a question of balance.

[thedoctor]

Yeah, besides trying to stabilize an already supposed to be stabile neck from outside forces(string tension, force of hand on neck, etc.) the trussrod is really there to set the relationship between the plane of the fretboard and the run of the strings. In the simplest way to look at it, it is supposed to counter the pull of the strings but that is not why they came up with cool things like 2-way and self-tensioned one-ways. I see the rod assy. as a way to get the plane you want your strings to sit on while you apply your infuence on them. You would normally need only the tension rods that come on most guitars if you don't mind the wood of the neck being put in constant compression in order to put the neck in the proper plane you can adjust your PREFFERED action TO. I don't like the thought of the neck being in an un-natutral compressive state to take the back/front bow out of it so I can set my desired action. Flat notes and stuff come from that, I believe. Highlight believe. I prefer a rod that exerts it's own back/forth force without involving the wood of the neck at all except for something to act upon. The only reason I am so "****" , no I don't mean that. Convinced. That works. After about 15 years of looking for what I consider "MY" sound, I found it by repairing a neck with a non-compressive trussrod like you guys are discussing. NIRVANA! Where is that registered trademark thingie when you need it?

[jay5]

Ok, thanks for all the responses. I have encountered a small issue that im hoping isnt a problem but may be. The hotrod I have is 18" long. I am making a tele neck. The length of the rod when the tip of the nut is under the guitar nut only gives me about 1/4" of wood between the channel and the heel. Can someone tell me, is this enough? Is that part of the neck stressed at all?

[westhemann]

The hotrod I have is 18" long.

should not be an issue.

[Guitarfrenzy]

Jay5 that should be enough for most truss rods easily.

I'm a firm believer in the newer dual action truss rods, they work great and are easier to install. Never had a problem so far, but you must install them the correct way. As far as neck twisting goes, yes, it can and will happen to some necks and if your really worried about it you should use carbon fiber rods about 1/8" away on both sides of the truss to prevent it from happening. They really make the neck super sturdy and doesn't add very much weight since they are light, and makes your neck not have any dead spots on it, which makes tone that much better. But that's just from my experience, everyone is entitled to their own judgement.

[frank falbo]

I don't know how you want your headstock to look, but I always pull the hot rods back so that the rectangular brass collar is under the nut. On a Fender head, that would make the allen head appear to be a "bullet" adjuster. It would protrude from the hole in the headstock. If you wanted a little access hole for the allen wrench with nothing coming out of it (like the newer Fenders) then you are pushing the rod farther towards the heel.

It doesn't really matter where the rod ends up at the heel so long as it gets into that area. But the first few frets IMO are crucial to playablity. I like a rod to have a progressively greater effect as it nears the nut. I think moving the collar back as far as you can makes for a more even adjustment across the first 5 frets or so.

Also on those hot rods I want the brass collar as close as I can get it to the adjuster head without interfering with the adjustment. You'll find that if you roll both rods with your fingers you can get the brass collars to move more to the inside or outside of the threads.

[doug]

The ones from Allied are WEAK, some kind of poor import.

Stick with the ones from LMI.

The HotRods suck too, way too deep rout.

Keep the truss rod channel tight!

With all that hard work on a guitar don't cut yourself short over $10. It's not worth it.

-Doug

[rhoads56]

Epoxying the truss rod in to the neck pretty much guarantees it aint going to work efficiently.

Sorry Perry, but this indicates a pretty fundamental misunderstanding of how the Martin style rod works. The U-channel is arched by adjusting the rod, and forces the neck to adopt the same curve.

The rod may work, but not as efficiently if being glued in. If the rod cant slip in the slot, then it either needs to stretch or contract the wood around it, or the U channel itself. This is basic lamination theory.

[catnine]

The U channel martin rods I am refering to are faily thick aluminum 1/8 " all three sides . Also the rod itself is 1/4" in diameter and is of hard metal like a bicycle spoke . Also the rod is set on shims between the rod and the top of the channel to give the rod a bit of bow . The open side of the channel is taped over so epoxy does not enter the channel and bond the rod .

I can't sit here and say necks twist more with one type of rod against another with facts to present . This is my personal view based on a rod which is let only into the wood itself . Now here you do have a single action rod with a fixed not or T at one end and a washer and a threaded nut at the other end , it works by being set in as deeply possible , you need more wood above it than below to compress the neckwood to bring up the upbow caused by string tension , it you have it in the center it could go either way and to close to the finger board and it will not work at all .

This is one reason that along came the dual action rod also because many necks are so thin and add todays light gauge strings and you may end up with back bow .

The channel type rod does not depend on compression of the wood , if bonded to the neck slot it will transfer the bow to the neckwood .

Like I said , I have only used one hotrod dual rod and I don't like the idea of it , now if I were concerned about back bow then yes . I have never had this concern .

You should design a neck with a certain amount of upbow built in so you can always put a little tension on the rod , it does not take much . Just as a neck without an adjustable rod which martin used for many years , it was just an added bar of steel for strength , the neck was purposely designed with a bit of backbow so when strung to pitch you would end up with just the right amount of relief .

My strat necks since they are all rosewood slabs and all as all strats are one section of maple , not three sections as gibson uses with the center section with the grain running opposite the outside sections , this gives a stable neck , just as all wide boards are done . Other wise a wide board will go with the grain and bow .naturally .

My necks on the strats stay and I never need to adjust the rod , I put it in with a bit of upbow and snug the nut and leave it there and for the high action heavy gauged strings jumbo frets combination I prefer a .012 " relief .

Certainly for a modern guitar with a thin neck and light strings which seems to be prefered these days a dual action rod would be a better bet in getting the relief where you want it .

The hotrod if installed as directed and on a bolt on neck heel adjustment , can be pulled out and replaced if broken as is the case with Rick's two rod system . Of course if someone is wrenching on it this much the guitar is in the wrong hands .

The one main reason I do not like hotrod truss rods it here you have a round rod with just the very narrow surface of the rod in contact with the back of the finger board , now remember the rod is round so only a small area is in contact with the back of the fingerboard . You are putting alot of pressure there . The channel is flat and has a great deal more surface area and you can add a maple filler for added strength and added gluing surface for the fingerboard . A hotrod you are routing 7/32" wide with a neck width at the nut say average 1 5/8 " now you have 1 3/8 " (give 1/32 back if you like ) left at this point near where the brass block resides for gluing surface . You have taken away about 6 % of the gluing surface .

I suppose if I had a choice with a hotrod I would rather the fingerboard split or pop loose than the back of the neck breaking through .

Call me crazy but I routed my hotrod a 1/16 " deeper and added a maple filler on top , since my neck is 1 inch thick overall I am not concerned about the back being too close .

[frank falbo]

Good points. I can add that whenever I use a hot rod I also carve a volute. I like volutes anyways, and usually include them regardless. But for the hot rod I think it's necessary because of that big brass block.

As for the fretboard splitting, remember that the hot rod slot is very narrow. If you get a good glue job, your fretboard is bonded (stronger than the wood itself ) to maple less than 1/8" on either side of where the rod is making contact. And the protective sleeve evens out the pressure a little. If you have a thick enough neck, I could see dropping it in deeper, and then use a volute to protect from a blowout at the headstock area.

I used one in a classical I made with an ebony board, and boy I'm glad I did. Currently it is applying a little forward bow. If I hadn't used a rod, or used a single action rod, I'd be stuck right now. But I realize that's a unique situation. I like what you're saying about the light gauge strings. I also think it's valuable with ebony, since ebony has a very wide range of motion. I have another neck made of maple with ebony strips, and an ebony board. It is as thin as the Ibanez wizard neck, with a hot rod. For about half the year it's applying very slight forward bow, and the other half very slight back bow. I try to make necks that can withstand string tension without much (or any) rod help. If I wanted to plane a bow into the neck, or open up my fret slots a little, I could use a single action rod. But the hot rod lets me build a neck for strength and not worry about it being too straight.

But I'm not so commited that I'd argue any type of rod. In fact, you've made me want to try a channel rod! I'd epoxy it in, too. The channel doesn't need to float in the slot, because any lateral move it would make in the slot as a result of the arch would be microscopic or undetectable. Physics could prove there's a variable as the rod's arch increases, but only in the wood that's above and underneath the rod, because the wood on either side would expand at the same rate. Since you're not glued to the fretboard above the rod, that leaves +/- 1/4" underneath the rod, which has to expand and contract regardless of what rod you use. If the neck was made of steel, perhaps the rod would have to float. But wood has elastic properties. Glueing the aluminum channel should increase stability, and greatly outweigh any theoretical decrease in function. The increase in strength would cause the rod to not have to work as much anyway

Edited January 5, 2005 by frank falbo

[Guitarfrenzy]

Actually guys,,, it's just a truss rod and as long as it will hold the neck in the position I want it to be without problems, then that's about all I can ask out of it, regardless of which kind I use. I've used a little bit of every one out on the market, and each have their stong points and weak points, but in the end it's really just a matter of how well it does it's job of keeping the neck from bowing back or forward from where you set it. So list all the pros and cons you want, I'll be in the shop working though, designing and building more guitars.. lol I'll let NASA do the strength test for me later on for each truss rod out... and start using the best ones when I get my reports in.. umm... still waiting..

[Setch]

The rod may work, but not as efficiently if being glued in.  If the rod cant slip in the slot, then it either needs to stretch or contract the wood around it, or the U channel itself. This is basic lamination theory.

I understand the arguement, but I don't agree. The U-channel is effectively a component of the neck once glued in, not part of the trussrod. The rod is still free to slide within the channel. It's no different to gluing in a CF reinforcement bar or laminating hardwood stringers into the neck - inevitably they'll be subjected to compresive forces by adjusting the trussrod, and in turn they'll make it harder to adjust the curvature of the neck, but that's part of the job they do, that's why folks laminate necks!

[SawDust_Junkie]

Falbo said :

I don't know how you want your headstock to look, but I always pull the hot rods back so that the rectangular brass collar is under the nut. On a Fender head, that would make the allen head appear to be a "bullet" adjuster. It would protrude from the hole in the headstock. If you wanted a little access hole for the allen wrench with nothing coming out of it (like the newer Fenders) then you are pushing the rod farther towards the heel.

This is something that perplexed me when I received the Stewart-Mac Hot Rod double action truss rod I used when building my first Strat copy. It was not possible to use an allen wrench to adjust that rod. The hex nut at the adjustment end was a 1/4" hex nut, but the hole in the end of the nut was not a hex shaped hole it was round, as in circular.

There was no way to insert an allen wrench in the end of that adjustment nut. I ended up having drill the access hole for the adjustment nut bigger in order to fit a 1/4" nut driver type tool in to do the truss rod adjustments. This was not too big of an issue as I put the access hole in the heel on this neck as it was my first one.

But I am curious as to whether the truss rod I received from Stewrt-Mac was defective, or has everyone else found that same thing on their Hot rods ?

And on a side note. Has anyone here used a Hot Rod for a Les Paul style neck ? Does the adjustment nut set too low in the channel to work as a peghead adjusted rod ? Or does the deeper setting nut actually make it better on an angled peghead ? I am working on a Les Paul copy as my next project, but I am using very cheap wood and such because this is a practice piece. I don't want to spend alot of money on Mahogany and good figured Maple, until I have my technique perfected ( or at least somewhat know what I am doing. ) Even though It is a practice piece, I would like to make it as viable and playable as possible. I was considering using a Hot Rod, but was not sure if it would work the way I want it to.

Edited January 5, 2005 by Fender4me

[doug]

curious...what's the fixation with Hot Rods?

you have a round surface that makes little contact with the back of the fingerboard. just sort of an edge really. plus it requires a deeper channel, and flexes around in it.

ones that have a flat bar or some other flat surface to contact the fingerboard just makes more sense. also, the channel is more shallow and you can use a regular sized bit to cut it.

I'm just not keen on the deep channel. I don't by mine from LMI, however they are the same. I've made a lot of necks, and these have proven themselves.

-Doug

[catnine]

Falbo said :

I don't know how you want your headstock to look, but I always pull the hot rods back so that the rectangular brass collar is under the nut. On a Fender head, that would make the allen head appear to be a "bullet" adjuster. It would protrude from the hole in the headstock. If you wanted a little access hole for the allen wrench with nothing coming out of it (like the newer Fenders) then you are pushing the rod farther towards the heel.

This is something that perplexed me when I received the Stewart-Mac Hot Rod double action truss rod I used when building my first Strat copy. It was not possible to use an allen wrench to adjust that rod. The hex nut at the adjustment end was a 1/4" hex nut, but the hole in the end of the nut was not a hex shaped hole it was round, as in circular.

There was no way to insert an allen wrench in the end of that adjustment nut. I ended up having drill the access hole for the adjustment nut bigger in order to fit a 1/4" nut driver type tool in to do the truss rod adjustments. This was not too big of an issue as I put the access hole in the heel on this neck as it was my first one.

But I am curious as to whether the truss rod I received from Stewrt-Mac was defective, or has everyone else found that same thing on their Hot rods ?

And on a side note. Has anyone here used a Hot Rod for a Les Paul style neck ? Does the adjustment nut set too low in the channel to work as a peghead adjusted rod ? Or does the deeper setting nut actually make it better on an angled peghead ? I am working on a Les Paul copy as my next project, but I am using very cheap wood and such because this is a practice piece. I don't want to spend alot of money on Mahogany and good figured Maple, until I have my technique perfected ( or at least somewhat know what I am doing. ) Even though It is a practice piece, I would like to make it as viable and playable as possible. I was considering using a Hot Rod, but was not sure if it would work the way I want it to.

You got the wrong model , there are three types of nuts on hotrods , one a slotted head for fender necks with the adjustment at the heel , another with a spoke wheel not , also for heel adjustment position for set neck guitars or neck through designs and the one you needed , a 1/4 nut with allen adjustment whicj is used for peghead adjustments , also if you wish you could use this on a bolt on neck for heel adjustment position . The only one for prghead is the 1/4" OD allen nut type and a 1/4" hole is drilled .

[SawDust_Junkie]

Hey catnine. That is the one I got. My truss rod has a hex nut for the adjustment. There is no slotted head on the nut and it does not have the spoke wheel nut either. Like I said the adjustment nut is a 1/4" hex nut on the end of the rod, but the hole in the end of the nut is not a hex hole that will accept a an allen wrench. The hole is a circular drilled hole. I was befuddled when I got it and discovered this, because every guitar I own uses a similar type adjustment nut on the truss rod, but on every one of them you can insert an allen wren into the end of the adjustment nut. Not on this Hot Rod truss that I received.

From your reply, I am starting to think that I did get one with a manufacturing defect. It seems that the adjustment nut shold have had a hex hole machined in the end of it instead of a round hole. But I guarantee you this one did not.

[frank falbo]

Um, there's no defect. You have the one with the hex head, and it needs to be adjusted with a nut driver style wrench. The reason there's a hole in the middle is so they can thread it on the rod before they permanently weld it on there. You're not supposed to be able to use an allen wrench in there. So you have to have a wider opening at the headstock to accomodate the wrench. The allen head model has a rounded head and an allen hole in it. It's a different model.

[SawDust_Junkie]

DUH ! Thanks frank. I went to Stewart-Mac and looked at the Hot Rod trusses again. I see exactly what you are talking about now. When I originally order my truss rod, I though the only difference between those two rods was the size of the hex nut. One being a 1/4" and the other being a 1/8". I see now that they are designed completely different. I will know what to use in the future now. Thanks again !

[Bill-Murray]

I'm gonna build a LP influenced guitar (Fretboard radius, scale, wood) and I want to have it peghead adjustable. I've never built a guitar and know little about trussrods. Which would you reccomend?? From reading it seams LMI is the best, because it uses a 1/4" bit, and the route is shallower. Any advice, or should I just go with the LMI one?? Thanks

[LukeR]

Hi man,

If I were you, I would buy Melvin Hiscock's book- it has a chapter on trussrods, and explains it all very well.

Luke

[doug]

Bill, it appears that many on this thread like the Hot Rod for some reason. If you've read their posts you'll see how it can be complicated and has inherent issues. A truss rod like the one from LMI has the hex inside and round outside, it only requires you to use a 1/4" bit, and is durable.

Set it in a little silicone at both ends and in a couple areas along bottom of the channel and set it in. DON'T GET SILICONE on the wood where the fingerboard glues on!

You'll need to hollow out around the adjusting nut of course, but you won't have to remove as much with this type of rod.

Oh yeah, check that book out too. Good info within.

-Doug

[westhemann]

A

truss rod like the one from LMI has the hex inside and round outside

this type is also available as a hot rod.

i have never tried those LMI rods...so i can't talk about them.i usually stick with what i know works.

i like the hotrod because i never have to worry about it...it is built like a brick house.

complicated?i don't see it...inherant issues?like what?the depth of it?if you don't want a wizard thin neck there is no need for worry.if you do by all means get the thinner rod.i prefer a slightly thicker,more stable neck...but that's just me

[sirkentesquire]

At the risk of adding unneeded opinion, I'll throw in some facts for fun!

I have used the LMI two-way truss rod thrice now, and it has been quite good to work with. Actually, they have a couple of different ones, but the ones I've gotten have had flat steel bar stock on top, as opposed to a rounded rod. The great benefit of that is the distribution of pressure on the fretboard. With the Stewmac hotrods the top rod is round, so all of the pressure on the fretboard is hitting only one point on the arc, though I guess their covering helps a tiny little bit.

I'm not saying any problems would occur from that, but by using a bar that comes in contact with far more surface area, your odds of having it crack the fretboard are lessened. Though I should add that if you are using a thick enough fretboard and are building your neck correctly you should have no worries one way or the other.

In any event, that's my reasoning behind going with the LMI rods as opposed to Stewmac's, which I thought about using once...mostly because they were a bit cheaper.