Builders/Repairers: What String Drop for Action?

[ChrisN]

I've seen two ways to do the same thing, and there are likely many others.

When setting action, some drop .003 string to string, while others drop .004. Of course, to complicate it further, I've also seen custom drops, usually for pros.

Question - which is the best/preferred (by the general population who cares about such things) string drop, .003 or .004?

Bonus Question - Whichever is preferred, why do you think that is?

[LeightonBankes]

let's say I set my;
E at 0.105" (@12 fret) and;
e at 0.085" (@12 fret)
0.020" diff., 5 spots (between)=0.004" drop from one to the next
E 0.105"
a 0.101"
d 0.097"
g 0.093"
d 0.089"
e 0.085"
set your outside strings and divide the dif. by 5, that much, nice and even (my choice)

[ChrisN]

Originally Posted by LeightonBankes

let's say I set my;
E at 0.105" (@12 fret) and;
e at 0.085" (@12 fret)
0.020" diff., 5 spots (between)=0.004" drop from one to the next
E 0.105"
a 0.101"
d 0.097"
g 0.093"
d 0.089"
e 0.085"
set your outside strings and divide the dif. by 5, that much, nice and even (my choice)

I get the process - I was wondering which was generally preferred by most regular folk, .003 drop per string (.020 drop total), or .004 (.015 drop total).

[fazool]

I set my action very low for light fingerstyle playing.

At the 12th fret I aim for the following

#1e .054" (3/64-4/64)
#2B
#3G
#4D
#5A
#6E .085" (5/64-6/64)

So, if I interpolate linearly, that would be .030" for 6 strings, so like .005" drop per string (-ish)

[ChrisN]

Originally Posted by fazool

I set my action very low for light fingerstyle playing.

At the 12th fret I aim for the following

#1e .054" (3/64-4/64)
#2B
#3G
#4D
#5A
#6E .085" (5/64-6/64)

So, if I interpolate linearly, that would be .030" for 6 strings, so like .005" drop per string (-ish)

Thanks - what I'm working toward is a uniform drop distance for each string so none is sticking up even a little bit, relative to the one before it (direction = E to e, for this purpose), to reduce chance of inadvertent finger strike(s). I've seen .003, .004, custom, and now your .005-ish. I wondered if those who are asked to build/repair for customers with a preference (or their own), were partial to either of those (.003 or .004), for some reason.

[LeightonBankes]

I used to be a machinist, went to school for it and worked in industry. I have been seeing your posts, and I want to say; I'm no luthier, by a long ways, but something I've learned along the way. A machinist wants to deal in absolute numbers, but WOOD doesn't work that way. .002" today could be .004" tomorrow if it rains (for instance). When it comes to guitars, people more often do what "feels right" rather than what measures best that day

[charles Tauber]

Originally Posted by LeightonBankes

A machinist wants to deal in absolute numbers, but WOOD doesn't work that way. .002" today could be .004" tomorrow if it rains (for instance). When it comes to guitars, people more often do what "feels right" rather than what measures best that day

True.

Years ago, I read an article by a then well-respected repairman and author. The article was about the geometry required of a fingerboard so that when it is under tension it matches the string's vibrating arc. In the article, he gave dimensions for the curve at each fret, measured in thousandths of an inch, that would match the parabolic curve of the vibrating string. (Never mind that the vibrating string isn't a parabolic curve.) What went through my mind at the time, a time long before wide-spread use of CNC machines in luthiery, was how the heck does one actually make that.

What I've done for decades is to level fingerboards with a hand plane, prior to fretting, and then use a 24" long aluminum spirit level with sandpaper glued to it. I run that up and down the length of the fingerboard. The motion just so happens to sand a slight (back-bow) curvature along the length of the fingerboard, a curvature that when the guitar is fretted and tensioned, works out just right. I gauge by eye how much the spirit level rocks. When it's "just right", I'm done. There are lots of things that are like that, where measurements tend towards being qualitative rather than quantitative.

[ChrisN]

Originally Posted by LeightonBankes

I used to be a machinist, went to school for it and worked in industry. I have been seeing your posts, and I want to say; I'm no luthier, by a long ways, but something I've learned along the way. A machinist wants to deal in absolute numbers, but WOOD doesn't work that way. .002" today could be .004" tomorrow if it rains (for instance). When it comes to guitars, people more often do what "feels right" rather than what measures best that day

I agree, but "feels right" usually comes after a lot of "feels wrong." When I started this journey, I had a used guitar that I didn't set up (didn't know how) and played it. I kept screwing up, despite the fact I knew the notes cold. What's going on? It "feels right," so what's up?

Started learning more, got a couple of other guitars that I played the same thing on the same way, but without the same problem. What the heck is going on with that first guitar? Finally did more than check just the E and e action - I checked the individual string action and guess what? That B string that felt fine to my inexperienced hand was sticking up several thousands more than the G and e on either side of it. I couldn't see it, and a more experienced player would have felt it, but I'd play those three strings and bump into the B coming and going, unless I remembered to raise my finger. I fixed the B string action and the problem went away.

So I think "feels right" and "being right" can be two different things. "Feels right" can be "right," or "wrong," and the inexperienced (me) won't know. "Being right" will always "feel right", then comes the issue of "what might feel a little righter, for me?"

You make a good point about wood being different - overnight expansion/contraction of the wood likely is affecting my "precise" action and saddle settings. I learn something new every day, and I like it.

[ChrisN]

My other impetus for this thread were these two threads:

murrmac123 likes a .004 drop between strings:
http://www.acousticguitarforum.com/f...38&postcount=6

While Todd Yates likes .003:
http://www.acousticguitarforum.com/f...38&postcount=6

[arie]

Originally Posted by LeightonBankes

I used to be a machinist, went to school for it and worked in industry. I have been seeing your posts, and I want to say; I'm no luthier, by a long ways, but something I've learned along the way. A machinist wants to deal in absolute numbers, but WOOD doesn't work that way. .002" today could be .004" tomorrow if it rains (for instance). When it comes to guitars, people more often do what "feels right" rather than what measures best that day

indeed. in the shop it's called "chasin' tenths" (.0000's) or in this case thousandths. .002~.003 -ok, that's doable for the most part in one measuring session, but those figures are going to change tomorrow or for that matter the longer you have your warm hands and work light on the guitar.

ChrisN fwiw, the consensus regarding right/wrong (as applied to musical instruments) only applies to the outliers or the furthermost parameters -best/worst. the grey area in the middle is the realm of "feels best" and is governed by personal preference.

[mirwa]

My process is very simple, I set the two outer E's to the height I or my customer desires at the 12th fret, I replicate the fingerboard radius to achieve the drop of each string between the E's

My targets are usually 80/60 for acoustic, 60/40 electric, 90/90 for banjos (21st fret), lowest action I have set was for an electric guitar and that was 45/30, so thats .004 per string and .002 on the super low action

Steve

[ChrisN]

Originally Posted by mirwa

My process is very simple, I set the two outer E's to the height I or my customer desires at the 12th fret, I replicate the fingerboard radius to achieve the drop of each string between the E's

My targets are usually 80/60 for acoustic, 60/40 electric, 90/90 for banjos (21st fret), lowest action I have set was for an electric guitar and that was 45/30, so thats .004 per string and .002 on the super low action

Steve

Thanks Steve. That's useful info. I didn't think about doing it differently for super low action, but that makes sense.

[LouieAtienza]

Originally Posted by ChrisN

I agree, but "feels right" usually comes after a lot of "feels wrong." When I started this journey, I had a used guitar that I didn't set up (didn't know how) and played it. I kept screwing up, despite the fact I knew the notes cold. What's going on? It "feels right," so what's up?

Started learning more, got a couple of other guitars that I played the same thing on the same way, but without the same problem. What the heck is going on with that first guitar? Finally did more than check just the E and e action - I checked the individual string action and guess what? That B string that felt fine to my inexperienced hand was sticking up several thousands more than the G and e on either side of it. I couldn't see it, and a more experienced player would have felt it, but I'd play those three strings and bump into the B coming and going, unless I remembered to raise my finger. I fixed the B string action and the problem went away.

So I think "feels right" and "being right" can be two different things. "Feels right" can be "right," or "wrong," and the inexperienced (me) won't know. "Being right" will always "feel right", then comes the issue of "what might feel a little righter, for me?"

You make a good point about wood being different - overnight expansion/contraction of the wood likely is affecting my "precise" action and saddle settings. I learn something new every day, and I like it.

Well you hit on another point - that what's "right" will vary from builder to builder. Not a heluva lot, but it will. The only way to know is to try different setups and see what works best for you.

Wood does move, and can quite significantly more than .003"-.004". And it can happen in a span of a few hours, let alone overnight. I certainly can not feel the difference between .063" and 064" string height off a fret.

Even the ballscrews on most of the CNC routers used in shops are C7 rolled, which is a lead accuracy of about .002"-.003"/ft. The more important factor is repeatability - meaning the ability to return to position without lash. There are very, very few guitar shops, if any, that have machines with precision ground ballscrews, because they're ridiculously expensive.

Consider the PLEK machine, which can actually measure and analyze the vibratory pattern of each string on a finished guitar, and shape the fretboard and level the frets (after installation) based on a player profile. It would be incredibly difficult for a human to recreate such a profile, yet we seem to come very, very close using just feel and judgment and whatever hand tools and measuring devices we have.

[Ben-Had]

To me it's the total combination of the setup i.e. string height over the 1st and 12th frets & the amount of neck relief that make playing more comfortable. They must be complementary to each other otherwise you can hit those numbers over the 12th and if they are high on the 1st the guitar plays harder.

[ChrisN]

Originally Posted by Ben-Had

To me it's the total combination of the setup i.e. string height over the 1st and 12th frets & the amount of neck relief that make playing more comfortable. They must be complementary to each other otherwise you can hit those numbers over the 12th and if they are high on the 1st the guitar plays harder.

Agreed. I always check nut height, and run the least relief possible. The guitar I'm working on now is .003 and it's been at .000 with no issues - feels great down low.