Parker135 - Posted - 01/26/2017:  12:33:06

I'd like to find some actual data to compare the tension of light steel strings (9, 11, 13, 20, 9) to Nylgut Classic Banjo strings.  I found a couple of places to get the numbers for steel, and I found data for nylon guitar strings, but I have not been able to find info for a direct comparison.  Any suggestions?

Tom Berghan - Posted - 01/26/2017:  12:51:59

I doubt you will find data specific to NylGut, a proprietary formula of the Aquila string company, but I found this on the web, so it must be true (tongue in cheek).  But the data you've already collected no doubt concurs. 

The string-load tension on a steel-string guitar is about 100 pounds higher than on a classical -guitar. As a result, a noticeable difference is the ease with which you can press on the classical guitar fretboard. Another direct outcome of the difference in tension is the type of sound the strings on each guitar produce. “A nylon string is more flexible and under less tension at pitch, giving it a slower attack and more mellow sound, while a steel string is under much greater tension providing a faster attack and brighter sound,” adds Córdoba head luthier Enns.

G Edward Porgie - Posted - 01/26/2017:  13:00:46

This site will at least give you some idea of what Nylgut actually is some of it's characteristics. It may not be as specific as you'd like, but it's a start.

aquilacorde.com/f-a-q/?lang=en

csacwp - Posted - 01/26/2017:  13:08:00

It's not just a matter of the actual difference in tension, it is a difference in how that tension is distributed across the length of the strings. Nylon is more flexible and allows for a more equal dispersion of tension, whereas steel pulls more from the tailpiece and the peghead, hence why heavy nylon will not warp a neck on a vintage banjo while light steel often will.

Parker135 - Posted - 01/26/2017:  14:03:58

Hmmm, still not getting to actual numbers, but interesting comments nonetheless.  George, that's a great read,  John, I don't follow your logic.  If we consider a string to be a series of springs linked together, even if the springs differ in stiffness, the force pulling at the end points will be the same no matter what the distribution of the springs in between, right?  It seems like it still comes down to comparing overall stiffness between the two string materials at a given pitch.  Thanks for your comments, guys.  More digging required I guess.

G Edward Porgie - Posted - 01/26/2017:  14:14:31

quote:

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Originally posted by csacwp

 

It's not just a matter of the actual difference in tension, it is a difference in how that tension is distributed across the length of the strings. Nylon is more flexible and allows for a more equal dispersion of tension, whereas steel pulls more from the tailpiece and the peghead, hence why heavy nylon will not warp a neck on a vintage banjo while light steel often will.

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If the string is at rest, the tension will be equal throughout its length (including at the tailpiece and nut) whether it's steel, gut, Nylgut, or twisted cat whiskers. The primary reason for necks getting warped is still probably the too-high tension of the steel most generally in use, and sometimes the neck wood itself.

HOWEVER, when the string is actually stretched by plucking or bowing it, the tension may be more evenly dispersed with a more elastic material. There is more "stretch" to nylon or Nylgut or gut, so more strain would be released in the material itself and less strain would then be put on some parts such as the tailpiece and tuner attachments. It's not actually flexibility, but a matter of "elasticity." Steel doesn't stretch like nylon. It just tries to yank on whatever it clings to, and it won't always come back to normal but will break or continue to stretch (if it doesn't first ruin what it's attached to). Nylon will stretch, so some of the force is absorbed before it affects the attachment points, and it then does return mostly to it's previous state. 

It's indeed a more complicated matter than a simple tension calculation. It's also why the tone differs between different types of string. Be aware, therefore, that you're taking a chance when trying to adapt a banjo designed for gut for use with steel--no matter how light your steel is--if only due to the elasticity difference.

Edited by - G Edward Porgie on 01/26/2017 14:21:41

crazybilly - Posted - 01/26/2017:  14:23:48

Maybe this site will help? I've used it for a while to calculate total tension:

chordgen.rattree.co.uk/tensiontool.php

G Edward Porgie - Posted - 01/26/2017:  14:37:13

quote:

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Originally posted by Parker135

 

Hmmm, still not getting to actual numbers, but interesting comments nonetheless.  George, that's a great read,  John, I don't follow your logic.  If we consider a string to be a series of springs linked together, even if the springs differ in stiffness, the force pulling at the end points will be the same no matter what the distribution of the springs in between, right?  It seems like it still comes down to comparing overall stiffness between the two string materials at a given pitch.  Thanks for your comments, guys.  More digging required I guess.

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I would never consider a string to be "a series of springs linked together." There are numerous types of springs, all reacting in different manners. Some springs work by compression, others by stretching, some by twisting. 

It also doesn't come down to comparing overall "stiffness."  A tuning fork, for example, is pretty stiff, but it's under no tension at all and still hums "A" when you whack it. A noodle at the same zero tension is very flexible, but just try to get a discernable tone out of one.

Edited by - G Edward Porgie on 01/26/2017 14:39:14

csacwp - Posted - 01/26/2017:  14:57:55

quote:

---

Originally posted by G Edward Porgie

 

quote:

---

Originally posted by csacwp

 

It's not just a matter of the actual difference in tension, it is a difference in how that tension is distributed across the length of the strings. Nylon is more flexible and allows for a more equal dispersion of tension, whereas steel pulls more from the tailpiece and the peghead, hence why heavy nylon will not warp a neck on a vintage banjo while light steel often will.

---

If the string is at rest, the tension will be equal throughout its length (including at the tailpiece and nut) whether it's steel, gut, Nylgut, or twisted cat whiskers. The primary reason for necks getting warped is still probably the too-high tension of the steel most generally in use, and sometimes the neck wood itself.

HOWEVER, when the string is actually stretched by plucking or bowing it, the tension may be more evenly dispersed with a more elastic material. There is more "stretch" to nylon or Nylgut or gut, so more strain would be released in the material itself and less strain would then be put on some parts such as the tailpiece and tuner attachments. It's not actually flexibility, but a matter of "elasticity." Steel doesn't stretch like nylon. It just tries to yank on whatever it clings to, and it won't always come back to normal but will break or continue to stretch (if it doesn't first ruin what it's attached to). Nylon will stretch, so some of the force is absorbed before it affects the attachment points, and it then does return mostly to it's previous state. 

It's indeed a more complicated matter than a simple tension calculation. It's also why the tone differs between different types of string. Be aware, therefore, that you're taking a chance when trying to adapt a banjo designed for gut for use with steel--no matter how light your steel is--if only due to the elasticity difference.

 

 

 

 

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You said it better than I could, and you are of course correct that it is elasticity, not flexibility.  

Parker135 - Posted - 01/26/2017:  15:00:33

I understand the differences among noodles, tuning forks, tension, torsion, and compression.  I still view the string, whatever it's made of, used in the context of pulling between two endpoints, as a series of hopefully identical springs, in tension.  Stronger springs will stretch less, weaker springs will stretch more, but this has no effect on the final force pulling between the endpoints.  As for the difference between nylon and steel, I don't see much difference as long as both are stressed below their elastic limits where permanent deformation occurs.  The question is still, what is the force required for a given string, to produce a certain pitch?    

Jake, I found that one also, and I think it's probably as close as I'm going go get to coming up with something to compare.  I'll input my string sizes and pitches to see what I can learn.  Thanks.  I was hoping someone knew where to find actual data from Aquila about their strings in particular.  I think I'll try contacting them.  

rudy - Posted - 01/26/2017:  15:31:29

quote:

---

Originally posted by Parker135

I'd like to find some actual data to compare the tension of light steel strings (9, 11, 13, 20, 9) to Nylgut Classic Banjo strings.  I found a couple of places to get the numbers for steel, and I found data for nylon guitar strings, but I have not been able to find info for a direct comparison.  Any suggestions?

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If you're interested in the technical details of Nylgut such as breaking strength, etc. it's available on the tech page of the Aquilacord website:

aquilacorde.com/f-a-q/?lang=en

rmcdow - Posted - 01/26/2017:  16:17:44

Here is another site that is useful when estimating string tension.

     cs.helsinki.fi/u/wikla/mus/Cal....html#TOP

Tom, on Aquila's site (link earlier in this thread) they say that Nylgut has approximately the same mean density as gut, so it has a higher density than nylon.  In Arto's calculator, that value could be entered into his formula instead of the value for nylon.

Edited by - rmcdow on 01/26/2017 16:27:31

Tom Berghan - Posted - 01/26/2017:  16:31:39

Well boys, I ain't no physicist ... but I have played a variety of instruments with gut, nylon, and various types of metal alloy strings for over 5 decades and I do know what my fingers tell me (sense of touch). Nylon is most flexible (including NylGut).  Gut feels a little stiffer than nylon - copper, brass, and bronze are considerably stiffer than gut, and I could be wrong but steel feels the stiffest of all. I like them all depending on the instrument I am playing and the type of music. There is a difference between flexibility and tension. I have never really trusted the calculations and find my fingers to be the best judge. When I was working in aerospace, we had some very expensive and sophisticated equipment for measuring tension and I would trust those measurements. 

Parker135 - Posted - 01/26/2017:  16:40:48

Well boys, I don't have 50 years of banjo experience, but I designed and built that equipment for tension measurement.  Just kidding,  Thanks everyone for your help.

Parker