nut slot height

[phavriluk]

Short version: I took a look at the string heights at the first fret, having capo'ed between the second and third frets, and near as I can tell, all the strings, all 12 of them, are just touching the 2nd fret (this job was done by a luthier, not me-the-bumbling-builder).

So...Is there any reason I can't stick a .010 ABS shim on the bottom of the nut and proceed to tend to the string slots? Sure beats making a new nut.

Thanks, everybody.

[Rudy4]

Originally Posted by phavriluk

Short version: I took a look at the string heights at the first fret, having capo'ed between the second and third frets, and near as I can tell, all the strings, all 12 of them, are just touching the 2nd fret (this job was done by a luthier, not me-the-bumbling-builder).

So...Is there any reason I can't stick a .010 ABS shim on the bottom of the nut and proceed to tend to the string slots? Sure beats making a new nut.

Thanks, everybody.

Do you mean they are all just touching the FIRST fret?

Ideally it's preferred to see a few thousandths gap between the first fret and the strings, but you might be OK if they are JUST touching and you are a light player.

Why not add a shim under the fret? Because it's the wrong thing to do. It's best to take pride in your work and do it correctly.

[phavriluk]

Rudy, there is the idea of 'prototyping' in play here. Much easier to shim a nut than to experimentally make a new one.

[John Arnold]

If it is not buzzing on open strings, then I would leave it.
The theoretical ideal nut height is the same as the frets. The only reason for setting the nut any higher than the fret plane is when it buzzes more on open strings.
One possible explanation is that in the act of putting the capo between the second and third frets, the string is pushed up as it is flexed across the second fret. That means that the string is raised slightly above the fret plane. The same applies at the nut. That is why it works better to have slight clearance between the string and the first fret when checking it this way. In any event, the necessary clearance is slight....a strip of copy paper (0.002") will work as a gauge.
An alternate way to check nut height is with a thin straightedge that is placed in the slot and on the first and second frets. I use a thin razor saw blade for initiating nut slots, and I simply flip it over to use the back edge as my straightedge to check the height.

[srick]

Frank Ford has a simpler solution.

Get a mailing label (such as used in a laser printer), place your nut on the adhesive side and cut around it with an x-acto. Voila, you’ve just bought yourself 7 or 8 thousandths. Or you could use two. I have used the trick many times and it doesn’t make a difference in the sound as far as I can tell. Plus, it’s reversible.

[phavriluk]

thanks, folks.

Well, I have an overabundance of return-address labels, and the price is right. I'll hold that thought.

[John Arnold]

Any buzzing on open strings?

[phavriluk]

John, no buzzing now, but there was a breakdown of understanding 'twixt me and the luthier who installed the bridge for me, and the saddle's a mile high, unaltered from birth, high enough to render any conclusions irrelevant till I tend to the saddle and relief. The nut was my first stop in getting this pile of parts to make music.

[John Arnold]

Regardless of the saddle height, the correct nut height should always be the same.
The common error is to measure action at the first fret. In that case, saddle height will have an effect on the measurement.
But setting the nut height even with the fret plane will always work, simply because placing a capo on the first fret creates a new 'nut' that is at fret height. If it doesn't buzz at capo 1, a nut set at fret height won't buzz, either.
The only caveat is that relief should be in an acceptable range for this to hold true.
I always check/set relief first, then the nut, and saddle last. That way, you only have to do it once.

[Andy Mitchell]

Originally Posted by John Arnold

Regardless of the saddle height, the correct nut height should always be the same.
The common error is to measure action at the first fret. In that case, saddle height will have an effect on the measurement.
But setting the nut height even with the fret plane will always work, simply because placing a capo on the first fret creates a new 'nut' that is at fret height. If it doesn't buzz at capo 1, a nut set at fret height won't buzz, either.
The only caveat is that relief should be in an acceptable range for this to hold true.
I always check/set relief first, then the nut, and saddle last. That way, you only have to do it once.

Zero fret guitars come to mind as sort of confirmation that this approach to setting nut height works.

[redir]

I'm with John on this one, if it aint buzzing leave it. Unless perhaps the relief is way to high then you would want to adjust that and then most likely you will have buzzing.

To get an idea of how high the strings should be hovering over the first fret when you do the 3rd fret test for nut string height press and hold the first and the 3rd fret and observe the height of the string over the second fret. It's only a very very little bit and that is the height your should see over the 1st fret when doing the 3rd fret test. Hope that makes sense.

For shimming a nut I like using white typing like paper and very thin CA. It dries rock hard and typically adds just enough height on a too low nut to get perfect with a few file swipes back.