Hello and good morning nation!
I have been building solid CBG style guitars for the last 3 to 4 years now and in all my builds, I always install a non-adjustable truss rod into the neck. Usually 1/4 inch thick metal rods.
The reason I do this was from watching too many manufacturing videos on how they build guitars and how they install truss rods. I figured I must be doing the right thing. My ignorance tells it reinforces the neck.
However, I saw a video from a Fender authorized shop, and the builder was installing a truss rod. And to my surprise, the truss rod was a flimsy wiggling thing, like a string of spaghetti.
I understand the truss rod is to settle any bowing that the neck may accumulate over time. But what about reinforcing, does it reinforce? Am I wasting metal rods?
I saw acoustic guitars built too and they get a nonadjustable permanent truss rod shaped like a T.
Replies
An Adjustable Truss Rod would also be great for if you're modifying 3 or 4 string Cigar Box Guitars into versions w/ 5, 6, or more strings. One of the Truss rods I have is a reverse action truss rod (lefty tighty righty loosey) because it came out of an old Left Handed Requinto.
A simple metal rod does not offer much reinforcement. As mentioned, an adjustable metal rod laid into an arched channel can be tightened to introduce some back bow. Watch a YouTube vidoe of someone cutting a channel into a Fender style neck.
https://www.youtube.com/watch?v=khX5z2HGLto
If you install a two way truss rod that can bend both ways, you can just cut a simple straight channel that need not be arched.
If using a fixed truss rod or beam, there are lots of choices in aluminum or carbon fiber. As mentioned, a bar on edge has a wider profile and more rigidity than a square or round rod. It's also easier to route a square edged channel and fit it in tightly than a chaneel to house a round rod.
https://www.stewmac.com/luthier-tools-and-supplies/materials/truss-...
Another way to stiffen the neck is just add a 1/4" fretboard. That makes the whole neck thicker and stiffer. If you shape the back, you don't have to worry so much about removing too much material.
If you put in any kind of rod, it should fit in snugly for the best function.
Another option is a laminated neck. Instead of one piece of wood, glue 3 or more together and cut to size. The varying grain directions make it stronger and stiffer than a single piece of wood. This is sometimes used on full sized bass guitars without truss rods. It can also be really pretty!
http://www.jchamiltonguitars.com/design/laminated-necks/
Scott
I should mention that not all Maple necks are quarter sawn. But that is a hard and pretty stable species.
Taff
Hi again IG, thanks for coming back, It's always good to hear how members' suggestions benefit others.
One thing that is also important in designing a stable neck is grain orientation. I always use neck material that is sawn on the quarter from the log, for full size and CBg style guitars. This is a way to add resistance to string pull when not using a rod.
In the photo, you can see what I mean if it ain't like that I'll come back another
day and pick the eyes out of the stack.
The other photo shows how I would oppose the grain to get stability from timber cut just off the full quarter...
And of course, a nice stiff fingerboard also helps.
Cheers Taff
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Like Tom said, most 3-4 stringers don’t need it if using maple, Seagull has been making the 4 string Merlin with maple necks without truss rods with great success? I like two-way truss rods strictly because of the setup aspect, trying to adjust relief without it is quite a lot of work. You’d be surprised of how many beginners that know nothing about relief or how affects their playing, but I say, if that’s how you do it & it works for you, then keep doing it, it’s your thing?
Thanks Brian Q! Had no idea about Seagull necks, interesting. Unfortunately, maple is a mail order wood for me on the island. It's not in hardware stores and guitar shops that do carry it are at double StewMac prices. Though there is a specialty wood shop, which is sponsored by Ace Hardware store. Last I was there, they had a huge redwood log size of a semi truck in the yard. Been meaning to visit them again, but it's real far and deep in an industrial park area. I can only visit it once a year with my schedule.
Hi I G, my take on this is based on my experience of using different types of neck reinforcement over close to 45 years or so.
I found that a straight round steel rod, the length of a neck, that can be bent between my thumbs will most likely also bend under string tension or timber movement. If it is stiff enough to resist bending it may be too large for the job.
I have always suggested that a flat bar is far more resistant against bending when fitted into the same width channel in the neck. EG: a bar 1/4"x 1/2" has more resistance to bending up than a 1/4" diameter rod. In fact an Aluminium bar 1/8" x 9/16" offers more resistance when fitted tightly in its channel.
My early 1970-80 steel-string guitars had steel bars [key steel] of the size mentioned above. I still have two of them] and the necks still have perfect alignment and action. Although I will mention a bit neck-heavy. The T section reinforcement allowed for the stiffness to remain while a lot of the weight was lost.
The heaviness/mass in the necks contributed to great sustain when played. Now I combine adjustable truss rods and carbon fiber bars.
To use a round rod it is best if it is adjustable, fixed one end with a nut adjusting from the other. In effect trying to shorten the rod when tightened. However, this will not have the desired effect of countering the pull of the strings or the bowing of the neck.
The rod needs to be bowed in its channel in a way that as the rod nut is tightened the bow in the rod is "flattened" out, taking the neck with it in the desired direction. This can be seen in cheap reinforcing systems that use a U channel with a round rod running through it. The rod does not sit flat but has a small steel riser in the middle of the U channel creating a bow in the round rod.
These only work one way, pulling down against the pull of the strings.
A two-way version is shown that I make myself. as the adjusting nut is tightened or loosened the truss rod [which is bar-shaped] bends up or down.
I know, I know more info than you needed......
Taffy
All info from you is well appreciated Taff, thanks for chiming in!
Thanks for confirming an idea I had of bowing the truss rod a tidbit. But I like your diy design! Is there a thread on diy truss rods? I'm not at that level but a good thread can cook into my mind and after a while I can do it.
I am currently carving a Poplar neck with a Red Oak fretboard for a 3 string CBG without a truss rod. I expect it will be just fine, especially since it will be tuned down to E B E.
Sorry, I can't quote a post either.
"The need for a truss rod (adjustable or not) really depends on the build.
If you build three and four stringers with Maple or Mahogany necks, the strength of the wood pretty much exceeds the ability of the stings to pull a bow in the neck. That's assuming a reasonable selection in string sizes. Strings that have a tuned-tension of around 16~18 lbs do not exert a lot of pull on the neck. If you are using softer wood for the neck, then all bets are off regarding no truss rod. Oak may be okay but Poplar is usually too weak when shaped to a good playable shape.
If you are building 5~6 stringers, the need for neck reinforcement begins to come into play depending on the neck wood and neck shaping. I've built 5 stringers with mahogany and maple necks and no truss rod (and not problem). With six stringers I install an adjustable truss rod just to be safe.
I'm sure there are more opinions on this matter and I hope people share them."
Popular isn't necessarily a bad wood for necks, but is more apt to bow than the harder woods I mentioned. It yours is holding up, don't worry about it. Just keep building.
Thank you Tom T, Taffy Evans, Carl Floyd and Brian Q!
Great awesome tips, I was trying to reply last week but nothing worked not even the HTML trick. Though I did find another way to post while in Visual Mode; just type up what you're gonna post, now copy your entire posts, tap "Add Reply". Your post will appear but will be in blank. Simply hit "Edit" and paste your post and tap "Save". And viola, your posts are on the air
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