Nuts, more nuts, and string spacing gauges

[fender3x]

I am thinking I'll try this method...

http://www.bryankimsey.com/nuts/nuts3.htm

[Simon Barden]

You always need to relate the nut slot depth to the fret height. 0.020" (0.51mm) above first fret height would be OK, but above the fretboard itself, far too low.

For me, 0.020" above the fret is higher than I like (as I normally get that or just over at the 12th fret on the top E on an electric). and I probably get it nearer 0.2mm/0.09" by trial and error. Error means a new nut, so I keep a stock of those.

When cutting a new nut with very shallow nut slots, I now tend to place another nut file across the neck by the nut (normally a 0.056") so I can cut down to a reasonable depth without having to keep checking the depth. This also then allows me to set up the guitar action with reasonably low fret slots and then finish off the nut slotting once the action has been set.

If I was setting up lots of guitars for a living and wanted to cut each slot once and not revisit it, or working on a rare/old instrument where you don't want to risk replacing the nut, then I'd probably use feeler gauges and play things safe with gap distances. But as I've got the time, I prefer doing it the 'cut a few strokes more' and see where I am method, with the strings on the guitar so I can see the effect in real time.

Maybe if I could find some 9.5" and 12" radius bocks/gauges of varying heights, I'd get those and use those, but personally I struggle with flat feeler gauges on a round fretboard.

[McCreed]

I find the "basic method" as he calls it, works just fine. To each his own.
Whilst nut work requires practise to get consistent results and learn what not to do, it isn't rocket science.
If I'm cutting a nut from scratch or starting with a pre-slotted blank, I do use feeler gauges for roughing in. Again, this is what works for me.

My gap targets (with capo on 3rd fret) are .008" E6 & A; .006" D & G; .004" B & E1. I know that doesn't create a perfect radius, but I've never had a complaint from a customer or problem on my own guitars using those measurements.

FWIW, when I first started doing nut slots I did step them evenly (.008"/.007"/.006" etc.) but I didn't notice a difference between that and my current method.

[fender3x]

That's helpful!

Does it make a difference if it's an acoustic or electric?

[Simon Barden]

You might want a slightly bigger gap for acoustic over electric, but it would be very minimal. In general the gap is bigger on the heavier strings as they have slightly larger amplitudes, so a 0.056” bottom E acoustic string will need a bit more room than a 0.042” electric bottom E. But the same would be true if you fitted heavy strings to an electric, especially if you downtuned. And acoustic players may pick/strum harder than an electric player would in order to get more volume. But it’s mainly string diameter that drives the gap distance, not the fact that it’s an acoustic or electric guitar.

[McCreed]

I should have stated that the measurements I posted above are general targets for your average electric.

TBH, it can very much be a case by case approach. For example I've done some set-ups recently for a couple of guys that use B Standard tuning. So they're using heavier strings with much less string tension, and things like nut action, neck relief need to be considered differently than an average electric using E Standard.

Like most things guitar, it's not always a one size fits all.

[fender3x]

OK, so maybe a bit higher than McCreed standard for an acoustic. Thanks!

It's interesting how much advice I see on this that does not involve a precise measurement.

[fender3x]

I have no idea why it added the image. FWIW, I know that the those are not the McCreed values ;-)

[Simon Barden]

If you wanted to play slide guitar, then you’d certainly want higher nut slots to stop you fretting the strings when you pressed down with the slide on the lower frets.

[McCreed]

I may be misinterpreting that chart, but the way I'm reading it, those measurements are from the bottom of the string slot to the fretboard (literally "at the nut") not the clearance at the first fret with a string depressed at the third. Without knowing the height of the first fret, those numbers are more less meaningless.