Will I Know When I Need to Tighten The Neck?

I think that allen bolt is the truss rod . . . one way of raising or lowering the action . . . by changing the angle of the neck.
That's the way I understood it anyway.
Hopefully, someone more knowledgeable will elaborate . . . like . . . does tightening it raise or lower the action?

some helpful links
http://en.wikipedia.org/wiki/Truss_rod
http://video.google.com/videosearch?hl=en&q=truss+rod&um=1&ie=UTF-8&ei=RIClSeTdOI3BtgeK9ujKBA&sa=X&oi=video_result_group&resnum=4&ct=title #
http://www.athensmusician.net/archive/2001-05-01_geneimbody1.shtml

Thanks, TL
That gave me enough incentive to tweak my guitar enough to fix an annoying problem.

When I was fretting the B string at the first fret (C), the string was buzzing.

Between loosening the truss rod (I think that's what I wound up doing) and adjusting the height of the bridge, it now doesn't buzz.

And I ended up lowering the bridge so the action is lower . . . which I like.

KR2

Thank you Mr Twisted - fascinating stuff.

It's great when you can learn something new about your beloved guitar. I haven't got a rule long enough to check along the frets, but next trip to MaxMat and I'm getting one...

I watched one of the vids and the guy said that different guitars have different ways of adjusting which I find a bit odd - my mechanical instincts tell me that if I tighten the truss rod I will make the neck bow and it will create a gap in the middle frets of the neck and adversely, the opposite the other way - this seems natural to me????

Again, fascinating stuff....

Thanks

Rock on!
D 8)

my mechanical instincts tell me that if I tighten the truss rod I will make the neck bow and it will create a gap in the middle frets of the neck and adversely, the opposite the other way - this seems natural to me????

The strings are pulling the head of your guitar one way (if you lay your guitar on a table, with the strings away from the table the strings will be pulling the head up), and the truss rod pulls the opposite way, counteracting the force of the strings. Tightening the truss rod pulls the head of the guitar further down.

I think that allen bolt is the truss rod . . . one way of raising or lowering the action . . . by changing the angle of the neck.

reinforcing what the wiki should have told you:

yes: the allen cap bolt is the truss rod adjustment
NO: the truss rod is not for raising or lowering action. action (string height) changes are secondary effects of truss rod adjustment, and the action needs to be re-corrected at the bridge once relief (truss adj) is properly set
NO: the truss rod does not change the angle of the neck, but it does change the curve or bow or more properly: the relief

I'm writing this out because two of your statements are common misapprehensions.

And thanks for the corrections.
I did understand it was bowing that was changed with the truss rod . . . after reading the wiki explanation . . .
. . . and not the angle.

You have to be careful when adjusting the truss rod, and its not some thing that you just tighten... and it IS NOT for your action of your guitar, the action is adjusted at the bridge... this is to adjust the "RELIEF" (how straight or curved your neck is). There is an order of operations when attempting to set up your guitar... which is essentially what you are talking about. It goes like this:
Head, saddle, nut (picture a horse to remeber the order... at the top is its head (meaning the truss rod), next on the way down is it's saddle (adjusting the bridge basically) , and finally its Nuts or nut(if the nut is too high or too low it can be sanded or a new one thats larger may be made)... just a trick to help you remember. Normally you will not need to adjust the nut and you probably don't have a sander and some bone to make a new one (you make a new one to raise the nut). So we'll just deal with the other two.. first is the truss rod... which is what you were talking about.... how it works: the truss rod is a rod that adjusts the bow or curvature of the neck you will need a FEELER GAUGE, these can be found at auto supply stores... you will also need a capo. Now .. take the capo and put it on the first fret of your guitar, with a finger on your right hand fret where the guitars neck meets the body on the side closest to your head on the LOW E STRING (opposite side of the cutaway) once you have both the capo and your right hand fretting the fret where the neck meets the body on the LOW E sting... you slide the FEELER GAUGE (.010 on the feeler gauge, for a 6 sting electric) in between the 7TH FRET ad the LOW E STRING your goal when adjusting the truss rod is to get that amount of space between the top of the 7th fret and the fret board, that is the correct amount of "RELIEF" in the neck for a standard set up. WARNING !!!!! before you adjust your neck and after you check the relief of the neck... you need to take the tension off of the neck by loosening all of the strings on the guitar... you will likely tune up and loosen several times as you adjust the relief of the neck (truss rod). Once you have the strings loosened to the point where the neck has no tension on it you can adjust the relief by using the allen wrench (fender) or the nut driver (gibson). To straighten out the neck (make the space at the 7th fret smaller) you will tighten the truss rod (turn clockwise) and to ad curvature to the neck (make the space between the 7th fret and the string larger) you would turn it counter clockwise. WARNING!!! you should NEVER EVER force a truss rod that is not moving fairly easily, if you are concerned perhaps you should take it to a luthier (like me). After turning it bit (start with just a 1/8 to a quarter of a turn you need to tune the guitar back up to pitch and repeat the process of checking your relief, you will notice that the space between the 7th fret (with your capo on the first fret and your finger on the fret where the body meets the neck) should be smaller or larger now... and remember your goal is .010 inches (use your feeler gauges). You repeat this process of checking relief, de-tuning, adjusting the truss rod, tuning back up to pitch until the relief is set at .010 . than you would proceed to adjusting the saddles. Adjusting the saddles requires some different tools... like a fretboard radius gauges, screwdriver/allen wrenches, a high quality tuner for adjusting intonation, and a 6 inch machinists ruler... so perhaps I'll explain that another time. REMEMBER... if you are not sure that you aren't going to break it DO NOT adjust your truss rod, the key is really not to force it and to ALWAYS DE-TUNE before adjusting, and yes you can do it without detune and it make work fine 10 times but than you strip the nut on the 11th, or snap the rod... so always detune. I hope that helps.

Ah yes, thanks EffectsGuru - basically leave the bloody thing to the professionals... :roll:

Thanks for the amazingly detailed tip. I might get a cheap guitar and practice a full setup before I even get anywhere near my G400.

Thought I'd reply to thank you for your time and effort on this question, even though it's about five weeks late.

Rock on!
D 8)

I doesn't hurt to CHECK your guitar one bit. That way you know if something is amuck instead of wondering about it. A set of feeler guages only runs about $10 US. You've got a Capo already, IIRC.