Nut work and intonation

chuck7

Senior member
Messages
319
As the pictures I posted show, I recent finished my LPS build.  I have never had to do any sort of work on the nut on any of my other guitars, so I have a few questions.  This may seem very amatureish, and if so, its because it is :)

When I tune up the A, D, and G strings, it seems like nothing happens for like 1/8th to 1/4 of a turn, then the pitch jumps and i hear a little <plink> sound.  I assume this is because the slots in the nut are too tight.  Is this correct? 

If so, how do I go about widening the slots?  I don't have any specialized sort of files for the job.  Do I have to buy a set of files?  I know one answer is "take it to a tech" but I don't want to.  I want to learn how to do this sort of thing myself. 

On a slightly different topic, I had some issues setting the intonation.  A, D, B, and High E all intonated correctly.  The A, D, and B saddles were all the way back before they did, but at that point they were nicely in tune.  The High E intonated correctly with the saddle ruffly in the middle of its adjustment.  The Low E and G string were a different story.  On both of them they were still considerably sharp with the saddle in its rear most position.  I took the saddle off on the High E and flipped it around backwards so that the edge that makes contact to the string was as far a way as it could possibly be and this got the string to a point where it was close, but still just a smidge sharp.  I couldn't hear the sharpness, but I could see it on the tuner.  The G string gave me pure hell.  I ended up stripping the screw head while trying to remove it and ended up just screwing it back in with some needle noise pliers before I did any real damage (as I was getting highly pissed).  Now the screw is so boogered up that I really need to replace it. 

Where can I get a screw like that?  Its not a normal screw, it has a bare spot where it rides in the bridge. 

Is flipping the saddle a decent solution to get the extra adjustment I needed?

Is there something else going on which is causing me to have to intonate most of the strings all the way to the back of the bridge?
 

GoDrex

Senior member
Messages
3,619
One thing I don't understand is, why does the 510 not need to be angled, but the TOM does?  I know the TOM is angled back so you can intonate the bass strings easier.

On the 510 is there a way to adjust the position of the entire bridge?

btw  -  I got files for the nut slots and found out that it's really easy to go too far with it hahaha. I'm not really cut out to be a guitar tech. ;)
 

chuck7

Senior member
Messages
319
well crap, there is a way to adjust the distance on each side of the bridge... its ok, call me a tard, i deserve it!  I wandered what that 3rd Allen wrench was for  :tard:

 

GoDrex

Senior member
Messages
3,619
I thought their might be - looked at the picture and it looked like there was more going on there then just a bridge sitting on two posts like a TOM bridge. I've never actually seen one of those in person so I wasn't sure.

You had me worried there. I was thinking it was some kind of scale issue or a mistake in routing or something. You should always have some leeway with those saddles for intonation.
 

tfarny

Senior member
Messages
4,481
use a scrap of sandpaper to just widen those nut slots a hair, taking it slowly. Pull the string out of the slot and just sand away at the side of the slot a bit, blow it clean, then apply trusty graphite from the high-tech mechanical pencil you keep at your side.

A way to check if your nut is too tight: Do a big bend or two on the offending string, checking tuning just before and just after. Did the bend cause it to go low? Then push down right behind the nut on the offending string. Can you get it back up to pitch that way, without touching the tuner? If so, definitely a tight nut.
 

chuck7

Senior member
Messages
319
Another question about the nut, how high should the strings be off the first fret?  If I do need to remove the nut and sand it down from the bottom, how easy is it to detach a Warmoth pre-installed nut?  How fragile is the corian to work with?
 

tfarny

Senior member
Messages
4,481
Is your nut really messed up, or are you just asking? The basic guideline is that the strings should not be lower in the nut than the height of the first fret. If they are, you'll get buzz on the open strings and your guitar will always just seem to suck. If they're much higher than that, your guitar will always have high action but will be great for slide.

To check that, apply capo just behind the 3rd fret, so that the strings make a straight line between nut and fret 2. You should have an almost microscopic clearance, but still visible, at the first fret. Might have to shine a light on it, hold the neck over a white sheet to really see it if its there.

I've never removed a warmoth nut and never filed corian, so I don't know those. But if your guitar basically plays good, I would just open up the slots a bit and leave it.
Post a close-up picture of your nut. Oh, I had a long thread about nuts and all this when I was new here. CB & Jack saved me from smashing up my practice parts guitar. The pics are no longer embedded, but here it is:
http://www.unofficialwarmoth.com/index.php?topic=716.0
 

-CB-

Senior member
Messages
5,427
go to

www.frets.com

Frank shows how to cut a nut.

Get a set of nut files.  You want files "just wider" than the strings you use.  Dont get dual sided or other fancy files, they generally need a lot of patience and practice to get right.  Get plain old straight sided nut files - Warmoth sells them, StewMac has them (the cheapest ones they sell).

For the .010 string, I use a .013 file.  For my .013 and .017 string, I use a .020 file.  For .026 string, I've got a .032 file.  For .036 string, I've got a .040 file and for the .046 string I've got a .052 file.

Frank likes to cut the slots a bit tighter than that, but he's anal in a good way about his nuts.  For the rest of us, going as much as .005-.007 over is not a problem as long as its a nice round cutting file and the slots are not too deep.

You need to angle your cut - so the "top" is right were the string leaves the nut and heads down the fretboard.  The angle isn't super critical, but too much angle and the nut will wear faster, too little and you might not have enough.  Try to split the difference between the angle the string wants to take to get to the tuner, and being level with the fretboard.  Thats just about perfect.

If you use sandpaper - you may alter the location of where the string leaves the nut... and thus whack your intonation all to kingdom come and then some.

Cut slow, you do this all with the strings on the guitar, but I find backing off the string tension just a bit... moving it over... cutting a few strokes... 3 or 4 only... lightly... then string back in the new slot, and tune up and see how it is.

PAY CAREFUL ATTENTION ON HOW TO DETERMINE THE DEPTH OF THE SLOT - www.frets.com has this all there, and Frank has made such easy work of it, and shares it with everyone... he is to be commended and given a raise.  Learn from the master's master there.
 

tfarny

Senior member
Messages
4,481
Really, CB? Even if it's fine, but just a smidge tight? I used 220 sandpaper on mine and got it right pretty quick.
 

chuck7

Senior member
Messages
319
Don't get me wrong, my nut is not "messed up".  I was just looking for some information regarding judging the height.  I think its a little higher than it has to be, but its certainly comfortable to play.  I do think the slots are a bit tight on  a few of the strings, but I really think that is the only correction needed. 
 

-CB-

Senior member
Messages
5,427
tfarny said:
Really, CB? Even if it's fine, but just a smidge tight? I used 220 sandpaper on mine and got it right pretty quick.

Yah... really.  If you consider, an unwavering hand (or machine) cutting the slot carefully with file.... and while not a knife edge, you dont want a rounded edge at all on the break side.  And you want the angle on the tuner side to be straight.  Sandpaper sort of takes the precision out of it.  It is a precise thing.

Plus, with sandpaper... how can you judge the width?
 

-CB-

Senior member
Messages
5,427
chuck7 said:
I was just looking for some information regarding judging the height.

This works REALLY well.

Tune up, make sure the neck is setup as it should be with relief.

Press the string just "after" fret #2, so your finger is in the third position, but against the back of fret #2.  Now look at the space between the bottom of the string and the top of fret #1.  There should be just a tiny tiny space there.  Maybe just a few thousandths of an inch.  If you cut the slot so the space is "just barely there", and that the space is consistent across the course of strings, you'll get a good string elevation every time.  -- thanks to Frank Ford on that one.

 

chuck7

Senior member
Messages
319
Well, last night I found that my suspected nut height issue was actually the need for a truss rod adjustment, not the nut height.  now the action is nice and low where I like it.  Also, prior to spending the money on nut files, I decided to take part of tfarny's advice and scribbled some graphite via a no 2. pencil into the nut slots.  That seems to have adequately resolved my string binding issues.  Now the last thing I have to do is reset the bridge position and redo the intonation.

Thanks to all who offered tips and information!
 
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