ok... poll please... "should the nut slots be cut so string sits exactly at fret height... or should they be slightly above"?

[mistermikev]

so... on a amateur luthier group on facebook... I'm confronted with something that goes against everything I know... well perhaps I'm wrong and will learn something... but not convinced.  so... the jist:

was talking about zero frets.  have never done one.  was under the impression that the common practice was to have a zero fret slightly higher than other frets.  I'm told this is wrong.  I've searched online and indeed can find sources that will go either way on this.  

this called into doubt how I setup a nut.  I have always been of the impression that you should cut the nut "slightly" higher than the 1st fret.  we're not talking a lot higher... but .015" higher.  

odd to me... that in this group the majority of folks seem to think you set the height of the string to the SAME height as the 1st fret.  so many so... that I'm convinced this will indeed work... but will not produce optimal action.  I suspect that if you set it to the SAME height as the 1... you will have to add more relief to the neck and possibly more fall away.  

what say you?

[curtisa]

What does experience tell you? 

Logically, the nut slots should need no more clearance above the first fret than would otherwise be required between the first and second, second and third, third and fourth, and so on. By extension if you could somehow level the nut slots to the same height as the frets while the neck is straight (as most builders would do normally), neck relief will take care of the rest and ensures that the string doesn't rattle on the next highest fret. That's why a zero fret shouldn't need to be higher than the remaining 24. 

In the real world some players like the safety net of some extra clearance at the nut, or like their necks super-straight, or play with a really heavy picking hand, or just like the feel of a little extra resistance in the first few frets, so you'd probably cut the nut slots a tad higher or install that zero fret un-levelled compared to the rest of the neck.

 

1 hour ago, mistermikev said:

but will not produce optimal action.

Depends on what you class as optimal action. That means different things to different people - best intonation, player comfort, player preference, buzz free etc...

[mistermikev]

4 minutes ago, curtisa said:

What does experience tell you? 

Logically, the nut slots should need no more clearance above the first fret than would otherwise be required between the first and second, second and third, third and fourth, and so on. By extension if you could somehow level the nut slots to the same height as the frets while the neck is straight (as most builders would do normally), neck relief will take care of the rest and ensures that the string doesn't rattle on the next highest fret. That's why a zero fret shouldn't need to be higher than the remaining 24. 

In the real world some players like the safety net of some extra clearance at the nut, or like their necks super-straight, or play with a really heavy picking hand, or just like the feel of a little extra resistance in the first few frets, so you'd probably cut the nut slots a tad higher or install that zero fret un-levelled compared to the rest of the neck.

 

Depends on what you class as optimal action. That means different things to different people - best intonation, player comfort, player preference, buzz free etc...

well... experience tells me that one can only ever know things to a certain degree of certainty... other than math... and even then I have seen a proof of 1 = sqr root of -1... and could not for the life of me figure how it wasn't at the time.  So now I always approach everything assuming that it is at least possible I am wrong!

experience... well it doesn't actually tell me as much as you'd think... because I have never actually measured if the nut I have cut is actually higher than the fret - let me elaborate:

when I set the nut I've got relief in the neck... and that is theoretically raising the frets as they approach the nut so 1st fret is higher than 2nd fret etc.  the strings is/are going over the fretboard at an angle due to the action set at the bridge... so technically the frets are closer and closer to the string as we approach the 1st fret which simulates them raising as we approach the nut.  So with that in mind... do I actually KNOW that the nut slots I've been cutting have been higher than the 1st fret?  if the guitar neck was set perfectly flat would I find they are in fact dead even?  iow the nut slot might only be actually higher with relief put into the neck and if we relaxed that... it is at least possible they are flat.  Even if I did that experiment and measured... I would still wonder if my action was as low as it could go.  So it's harder to "know" than I initially thought!

my gut does suggest it would have to be higher (if only in the case where we have relief in).. because if not... we are not allowing for any room for the string to vibrate over the 1st fret.

"To allow the strings to clear the top of the first fret, the bottoms of the slots should be .030" higher than the fret height." stew mac

"Then read the nut slot depths. As a starting point, shoot for .02” in between the top of the first fret and the bottom of the string at the first fret on the wound strings" https://nashville.mi.edu/adjusting-the-nut-slots/

[curtisa]

1 hour ago, mistermikev said:

"To allow the strings to clear the top of the first fret, the bottoms of the slots should be .030" higher than the fret height." stew mac

"Then read the nut slot depths. As a starting point, shoot for .02” in between the top of the first fret and the bottom of the string at the first fret on the wound strings" https://nashville.mi.edu/adjusting-the-nut-slots/

The former Stewmac quote perhaps overly simplifies what's trying to be measured, as the strings shoot off from the face of the nut in a straight line while the neck (theoretically) starts curving away with relief. The gap between the bottom of the nut slot and the top of the first fret is difficult to measure (they're diagonally opposite each other) and changes based on how much relief you have and how high the action is at the bridge.

The latter MI Guitar Craft one puts some of that missing detail back in by stating that the gap between the underside of the string and the top of the first fret where it passes overhead is where you measure, which makes more sense. And even then, it's only suggested '...as a starting point...'. Again, this is dependent on action and relief, but it is easier to quantify.

 

1 hour ago, mistermikev said:

if the guitar neck was set perfectly flat would I find they are in fact dead even?

Assuming you were chasing the 'perfect' action, to finish the job off you'd probably spend some more time sneaking Guitar Craft's suggested 0.02" clearance down a bit more. More than likely you'd end up with the nut slots pretty much the same height as the fret tops if the neck was indeed re-straightened out.

 

1 hour ago, mistermikev said:

my gut does suggest it would have to be higher (if only in the case where we have relief in).. because if not... we are not allowing for any room for the string to vibrate over the 1st fret.

But then what happens when you depress the string to the first fret? When you levelled the frets and dressed them you made sure all the fret tops were the same height with the neck straight, so by that definition surely the 2nd fret should buzz as it is the same height as the first?

[Bizman62]

As this is a poll, there's no right or wrong, right?

My logic tells that the nut slots should be just a hair above the fret level. Not much, just a hair. The trick to cut a pencil in half, sharpen it and slide it across the frets to draw a line on the nut is what I've learned to give a ballpark. Cutting that line will end up being lower than fret level and that would surely buzz!

But I can also understand the logic behind the "level" thing. Fretting a note creates a similar break angle to that of the nut and fretted notes don't buzz if the setup has been done right.

You're most likely familiar to pressing the third fret to see if there's space between the string and the first fret. But what happens if you put a capo on the first fret and press the fourth fret? Will there be a gap between the string and the first fret after it? Most likely not!

As said, I tend to roughly mark the fret level with a split pencil and cut the slots just to that line, and then work my way down by pressing on the third fret until there's only a tiny gap between the string and first fret.

Out of curiosity I took my digital calipers and measured the string height from the fretboard right after the nut and right after the first fret. The difference was a whopping 0.03 mm/0.00118" which is about a quarter of the thickness of an average human hair.

Conclusion: If you start from a pencil line higher and sneak your way down you'll end up your nut slots being almost level with the frets. Thus the original question is about splitting hair into fractions!

[curtisa]

34 minutes ago, Bizman62 said:

But what happens if you put a capo on the first fret and press the fourth fret? Will there be a gap between the string and the first fret after it? Most likely not!

Have you tried it? There should be a gap, even if tiny, as you're laying a straight object (the string) across an arc (neck relief).

[Bizman62]

37 minutes ago, curtisa said:

Have you tried it? There should be a gap, even if tiny, as you're laying a straight object (the string) across an arc (neck relief).

Now that you asked, I had to find my capo. I had already tried with my fingers but after testing the capo may press a tad harder. It appears that the high e string could hold a post-it note of 0.10mm/0.0035", the low e enabling a folded note go through easily. That was with a relatively straight neck. So yes, I was wrong there.

There's a reason for the high e having a narrower gap when a capo is being used: The thickness of the core of the string. Metal strings are stiff, they tend to continue upwards in an angle until they bend towards the bridge - where the same thing happens again and which is the reason why we need to intonate the strings. The thicker the string the stiffer it is and thus the higher it reaches until it arcs towards the bridge.

[mistermikev]

7 hours ago, curtisa said:

The former Stewmac quote perhaps overly simplifies what's trying to be measured, as the strings shoot off from the face of the nut in a straight line while the neck (theoretically) starts curving away with relief. The gap between the bottom of the nut slot and the top of the first fret is difficult to measure (they're diagonally opposite each other) and changes based on how much relief you have and how high the action is at the bridge.

The latter MI Guitar Craft one puts some of that missing detail back in by stating that the gap between the underside of the string and the top of the first fret where it passes overhead is where you measure, which makes more sense. And even then, it's only suggested '...as a starting point...'. Again, this is dependent on action and relief, but it is easier to quantify.

 

Assuming you were chasing the 'perfect' action, to finish the job off you'd probably spend some more time sneaking Guitar Craft's suggested 0.02" clearance down a bit more. More than likely you'd end up with the nut slots pretty much the same height as the fret tops if the neck was indeed re-straightened out.

 

But then what happens when you depress the string to the first fret? When you levelled the frets and dressed them you made sure all the fret tops were the same height with the neck straight, so by that definition surely the 2nd fret should buzz as it is the same height as the first?

"so by that definition surely the 2nd fret should buzz as it is the same height as the first?" well... this is what I originally thought... but then if the saddle height puts the string over the frets at an angle... could be that that angle is just steep enough that it clears the fret when it vibrates.  and we're back to "is the action optimal".  I guess it's too subjective of a question to ever really reach a definitive conclusion.  examining these details and having an intelligent conversation about them... has improved my understanding of the subject and for that i have benefited and appreciate your contribution to that.

I think about the typical practice/procedure for setting a nut.  you take a flat pencil and draw a line with the pencil laying flat on the frets... but then cut the slots just above that line.  suggests to me we never mean to actually hit exactly fret height.  further my recent experience with staying one hair further above that line... and then compensating by lowering the saddles one hair lower... and how that ends up 'feeling' lower near the upper frets... again suggests we want to remain above.

[mistermikev]

2 hours ago, Bizman62 said:

As this is a poll, there's no right or wrong, right?

My logic tells that the nut slots should be just a hair above the fret level. Not much, just a hair. The trick to cut a pencil in half, sharpen it and slide it across the frets to draw a line on the nut is what I've learned to give a ballpark. Cutting that line will end up being lower than fret level and that would surely buzz!

But I can also understand the logic behind the "level" thing. Fretting a note creates a similar break angle to that of the nut and fretted notes don't buzz if the setup has been done right.

You're most likely familiar to pressing the third fret to see if there's space between the string and the first fret. But what happens if you put a capo on the first fret and press the fourth fret? Will there be a gap between the string and the first fret after it? Most likely not!

As said, I tend to roughly mark the fret level with a split pencil and cut the slots just to that line, and then work my way down by pressing on the third fret until there's only a tiny gap between the string and first fret.

Out of curiosity I took my digital calipers and measured the string height from the fretboard right after the nut and right after the first fret. The difference was a whopping 0.03 mm/0.00118" which is about a quarter of the thickness of an average human hair.

Conclusion: If you start from a pencil line higher and sneak your way down you'll end up your nut slots being almost level with the frets. Thus the original question is about splitting hair into fractions!

funny, I did not read your post before my last.  

[mistermikev]

1 hour ago, Bizman62 said:

Now that you asked, I had to find my capo. I had already tried with my fingers but after testing the capo may press a tad harder. It appears that the high e string could hold a post-it note of 0.10mm/0.0035", the low e enabling a folded note go through easily. That was with a relatively straight neck. So yes, I was wrong there.

There's a reason for the high e having a narrower gap when a capo is being used: The thickness of the core of the string. Metal strings are stiff, they tend to continue upwards in an angle until they bend towards the bridge - where the same thing happens again and which is the reason why we need to intonate the strings. The thicker the string the stiffer it is and thus the higher it reaches until it arcs towards the bridge.

hats off... you have added another detail I hadn't considered.  I think it is fair to say at this point that either exact fret height OR slightly higher would work... and it's probably a matter of personal preference.  very much appreciate the thought.

[curtisa]

There's a good chance that most builders deliberately (or subconsciously) target cutting the  nut slots just above the fret height solely because any slip up at that point in the build renders the nut useless. It's easier cut them as close as you dare than it is to cut them *exactly* to the same height as the first fret.

I'd highly recommend doing a build with a zero fret when you get the chance. At the very least, not having to stress so much about getting the nut slots 'just so' more than makes up for the modest increase in assembly labour. Automatic setting of the action at the first fret is a massive bonus in its own right too.

[mistermikev]

31 minutes ago, curtisa said:

There's a good chance that most builders deliberately (or subconsciously) target cutting the  nut slots just above the fret height solely because any slip up at that point in the build renders the nut useless. It's easier cut them as close as you dare than it is to cut them *exactly* to the same height as the first fret.

I'd highly recommend doing a build with a zero fret when you get the chance. At the very least, not having to stress so much about getting the nut slots 'just so' more than makes up for the modest increase in assembly labour. Automatic setting of the action at the first fret is a massive bonus in its own right too.

to your first point - is a good point, have certainly done that dance!  

well it is on my bucket list and moreso because of this whole endeavor and just feel like I could only benefit from trying something different.  I get the benefit... the ones you mentioned... but even moreso the fact that one can then make drastic string size changes w/o needing to alter the nut.  that is a nice benefit.  also in theory the tone of the guitar should be more similar as you play open strings.  also a nice benefit.  that said... one still has to have a nut to hold string spacing so in a sense it's not really saving any work.  

honestly every time I've thought about trying it... my main reason for not was the idea that the last fret had to be a different fret size.  seeing that it is so common to use the sm frets has def increased the liklihood that i will attempt.  

[Bizman62]

4 hours ago, curtisa said:

There's a good chance that most builders deliberately (or subconsciously) target cutting the  nut slots just above the fret height solely because any slip up at that point in the build renders the nut useless. It's easier cut them as close as you dare than it is to cut them *exactly* to the same height as the first fret.

Exactly what I found out in my studies earlier today! When targeting to the "just above fret height" with the flat pencil and third fret methods you end up a quarter of a hair higher than the frets.

Another thing is that I can't think of an easy way to cut the slots exactly to the same height with the frets. A flat spike scraping a thinner line than the pencil?

[mistermikev]

6 hours ago, Bizman62 said:

Exactly what I found out in my studies earlier today! When targeting to the "just above fret height" with the flat pencil and third fret methods you end up a quarter of a hair higher than the frets.

Another thing is that I can't think of an easy way to cut the slots exactly to the same height with the frets. A flat spike scraping a thinner line than the pencil?

perhaps a file that has a safety edge on half it's length and you ride it on the frets while cutting the nut.  in light of this idea of them being exactly as high as the frets... i was wondering why no one has made something like this if that is the way to go.  I guess the main problem is you'd still have to cut the fall away on the nut.

[curtisa]

6 hours ago, Bizman62 said:

Another thing is that I can't think of an easy way to cut the slots exactly to the same height with the frets.

Stewmac make such a product. It's an expensive way to do it though. It also suggests to me that the sort of person who'd buy it is after a quick, no-thinking solution - something where you'd just lay down the feeler gauges and hack away with gay abandon using files until the nut slots are all in position. Might be handy in a full time shop where time is money?

[Bizman62]

Thanks for the information! A half safety file is an obvious tool but as Mike said you'd still have to cut the fall away.

I've never considered cutting the nut slots as a very time consuming task even with my roughened feeler gauges. But for what I've seen on videos it can be made such. Take Jerry Rosa for example: He tends to start the slots with a razer saw as the files are so slow. But he starts with a large margin. If the nut is cut low enough before slotting it shouldn't take too long to file them with just a few strokes.

The string spacing ruler is a nice thing but the full set looks like it takes more time to set up than it saves time.

[mistermikev]

i always buy precut nuts... worth the $10-20... then just a few strokes with the files.  saves the files too.  not really changing my methods based on this debate or its' parallel debate on facebook group... other than my choice is now more informed.