Tip of the Day/Truss Rods

Before attempting any adjustment to the truss rod, please read all the way through. What is a truss rod? You've no doubt heard the term. A truss rod, or truss rods,(on some instruments there are two) is located within the neck of the guitar.They are meant to employ relief against the natural stress of the strings. If you look down a neck of a guitar from the bridge to the nut, you will most likely see a vey slight "dip" in the neck, away from the strings.If this curvature was not there the first symptom is a buzzing of the string rubbing on the fret when the string is vibrating.The truss rod can be adjusted to eliminate this buzz ,or at least reduce it.Of course the ideal action ,for most guitarists, is to have the strings very close to the neck, but without string buzz.However, there are a lot of variences in what kind of 'action ' a musician wants on their instrument. These factors include, type of music being played,the players preferences and just what may or may not be possible for a given instrument.
Different instruments have different types of truss rods.There are dual truss rods on some basses, because they require more strength and the ability to remain true.Some truss rods are not meant to be adjusted. There purpose is to add strength to the neck.For simplicity purposes, I will talk about truss rods found in most electric guitars.
The rod end is usually found behind a small plate that is located on the machine head right next to the nut.The machine head is the place where your tuning keys are.You might have thought that the plate was just a convenient place for a logo;not.
When do I know that a truss rod adjustment is in order? There are so many variences. If the action is low, doesn't neccesarily mean you need to adjust the truss rod. The other controlling factors can be found in the nut or the bridge.It also depends on the why on a needed adjustment. Are you just wanting a "faster action, or is there a noticable buzz?Is there a flat or backwards bend to the neck?If you guitar sounded and played well and then seemed to change, it could be that the neck has settled into a recently adjusted position and that further adjustment is warranted.
To check the amount of forward bend in the neck, and you don't have an actually straight straight edge, you can fret a string, that is tuned to the tuning you actually play in. Fret the string at the first fret and at the twelth fret(you can use a capo at one or both of these points to free up your hands for measuring). Mearsure the gap ,( you can use a feeler gauge)if there is one, at the mid range between fretted points.The amount of gap desired gap can be anywhere from .004-.012 depending on your desired action and what type of strings and how you play.If there is no gap then the neck probably has either some back bow or is absolutely flat.If there is a gap,depending on how you play, what you play, string gauge and the instrument, you may want to adjust it.
If you have decided to adjust your neck,first make sure that you use a proper wrench for the adjustment.They are usually female hexhead nuts.I like to plug into a chromatic tuner as I turn the nut.The truss rod lies below the fret board,so when it is tightened "shortened" it bends the neck backwards.when it is loosened it bends forward, creating more space from string to neck.It is advised to mark the nut, so that you can not only see how far you are turning it, but so that you can also return it to the original position if needed.IT IS ADVISED THAT BEFORE YOU ATTEMPT TO MAKE AN ADJUSTMENT THAT YOU LOOSEN THE TRUSS ROD.We do this to insure that the rod is not already tightened all the way.You can do CONSIDERABLE DAMAGE TO THE ROD INCLUDING BREAK IT IF YOU OVER TIGHTEN IT.THIS IS NOT COOL. tHE REPAIR ,IF POSSIBLE, FOR THIS KIND OF DAMAGE CAN BE COSTLY AND CAN BE THE LAST HURRAH FOR INEXPENSIVE INSTRUMENTS.Start with a very slight turn, if you are trying to put more distan between the strings and the neck you want to loosen it.Lokk at the tuner, if you have loosened the rod and it has moved the neck forward, you should see that the strings are detuned somewhat.An eighth turn is all you want to do at a time. Now retune the strings, all of them. Now check the action again, by measurement and listen for buzz. How does it feel?Is it what you want?If furhter adjustment is needed continue cautiosly. If the tuning didn't change, check to see that the strings are not bound in the nut.You press down on them at the nut or use the capo to deprees them. This will free them up.Check action and tuning often during this process.
If you are not able to get the desired results with a truss rod adjustment,it could be that the gridge or nut need adjustment.These processes are a whole new daily tip.It is always a good idea to get an experienced guitar repair person or a tech to at least give you some pointers or direction. There are so many different possibilities of where a problem lies in adjusting guyitars , that it is not possible to know exactly what a certain instrument needs without actually seeing and hearin it.
Network with other guitar people in your locale. Take a cless and learn from a profeesional. You will learn more amd get a well rounded perspective.
Untill next time. Rock On.