Nut height

[Bernie Daniel]

This thread should be filed away somewhere for future reference. Lots of usable information here. So what should the action on fret #1 be (approximately) when the nut is set right?

The thinnest blade on my set of feeler gauges is 0.004" (0.102 mm) and that seemed to just slide under the first fret on the G-course when I got my Gibson F-5 back from a professional set up. So that is what I use as an approximate "go-by". The action (clearance) on the E-course was 0.007" (0.178 mm) on the same mandolin.

Other opinions?

[Mike Conner]

Good points regarding the need for a thinner straight edge. When setting up guitars with a 0.024" to 0.026" G string the repeated tighten - loosen - tighten again increases the risk the string will snap. I even bought a bulk pack of 0.024" PB strings as backups, but that doesn't help with Elixirs. I've never snapped an unwound string so no problem with just using the strings for setup.

With new instruments I've started using bulk PB strings for the setups for guitars or OM since they are pretty inexpensive per set (around $3 or so). Once I am satisfied with the setup I'll put on a fresh set.

All that being said, using the straight edge method will save some time and reduce the mortality rate of the wound strings.

[sunburst]

So what should the action on fret #1 be (approximately) when the nut is set right?

Short answer: I don't know and I don't care.

The correct string height at the nut is what is important, and when that is correct, the height over fret #1 takes care of itself. As we've said here in this thread, the correct string height at the nut is the same as the height of the tops of the frets (or very slightly higher). When that adjustment is made correctly, the height of the string above the first fret depends on the height of the action (string height at the bridge) and the amount of bow in the neck, so that measurement can vary when the nut is correctly cut. As far as I'm concerned, that makes it a functionally worthless measurement.
There are some who stack feeler gauges on the fingerboard surface to measure string height and cut the nut accordingly, To me, that seems beyond worthless as a measurement, because fret height and fret condition can be so vastly different from one instrument to the next.
A simple straight edge, whether it be a tightened string or a thin piece of solid, straight material (like a ruler), gives us all the information we need to adjust nut slots to the correct height, without us having to measure and assign numbers to action height, neck bow, fret height, or any other variable involved.

[MysTiK PiKn]

I agree. There are many variables involved. A general measure might be useful as you get close, in the ballpark. The ultimate measure is "how does it play" or "how does it feel to the player". Beyond all this, you have "feel" with a sharp file in hand - and a dull file might be the ultimate.

To me, making a nut is sculpture.

[Bernie Daniel]

Short answer: I don't know and I don't care.

The correct string height at the nut is what is important, and when that is correct, the height over fret #1 takes care of itself. As we've said here in this thread, the correct string height at the nut is the same as the height of the tops of the frets (or very slightly higher). When that adjustment is made correctly, the height of the string above the first fret depends on the height of the action (string height at the bridge) and the amount of bow in the neck, so that measurement can vary when the nut is correctly cut. As far as I'm concerned, that makes it a functionally worthless measurement.
There are some who stack feeler gauges on the fingerboard surface to measure string height and cut the nut accordingly, To me, that seems beyond worthless as a measurement, because fret height and fret condition can be so vastly different from one instrument to the next.
A simple straight edge, whether it be a tightened string or a thin piece of solid, straight material (like a ruler), gives us all the information we need to adjust nut slots to the correct height, without us having to measure and assign numbers to action height, neck bow, fret height, or any other variable involved.

OK, so what you are saying is to set the string at the nut to be the same as the crown height of the frets and the slope-away of the fret board down to the bridge will take care of the action? As per simplified (not to scale diagram below)?

[sunburst]

...so what you are saying is to set the string at the nut to be the same as the crown height of the frets and the slope-away of the fret board down to the bridge will take care of the action?

I think so. The first part is what I'm saying, but I'm not completely clear on the second part.
I think of the fret tops as the reference and the strings sloping up and away from the frets as they extend to the bridge, but I suppose that can be thought of the other way, with the strings being the reference and the fingerboard sloping downward.

This came up in another thread not too long ago. The correct string height at the nut is the height of the fret tops (like a zero fret, or a fret with a capo). The action and neck relief can then be adjusted depending upon scale length, string tension and player preference. The string height at the nut will be the same after any of those adjustments and will still be correct, but the height of the strings above the first fret (and other frets) can change slightly, hence my aversion to measuring the height of the strings above the fret.