Force required to fret a guitar string?

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Brian Evans
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Force required to fret a guitar string?

Post by Brian Evans »

I've recently suffered an accident that has left me with nerve damage in my left hand, making any pressure on my finger tips very painful. This made me think of wondering what the actual pressure required to fret a guitar string is. Given the normal setup parameters, does anyone have any idea? I had in mind that someone smarter than I could use a typical string tension, string height, length of string before and after the fret to come up with some kind of ballpark force...

John Clifford
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Re: Force required to fret a guitar string?

Post by John Clifford »

First, I'm very sorry to hear about your accident. That's a terrible thing for a musician. Second, I have no idea how to compute the exact amount of force required. But third, I have actually been working lately to see how much I can reduce the amount of force I'm using, as a matter of playing technique (assuming setup is already optimal). The answer is quite a lot! Just by paying careful attention to this, I've learned that I tend to use way more force than is absolutely necessary, especially when playing electric guitar. I wouldn't try to put a positive spin on your accident, but it might be an opportunity to actually learn better technique - at least if you get to the point where you can tolerate some amount of pressure.
Best wishes!

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Barry Daniels
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Re: Force required to fret a guitar string?

Post by Barry Daniels »

Lowering the nut slots to the absolute minimum will be useful in reducing fretting pressure.
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Bob Gramann
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Re: Force required to fret a guitar string?

Post by Bob Gramann »

Again not directly answering your question: Several years ago, I cut the tip of my index finger ac ouple of nights before an important gig. Even with a bandaid pad across the tip, I couldn’t fret even an extra light silk and steel string set. But, nylon strings made a huge difference. I was able to play the gig on a classical guitar (It was a singing gig so my guitar playing wasn’t paramount tot he performance.) The tension on a light gauge steel string set is in the area of 150 pounds on a 24.9 scale. On a classical guitar, string tension usually comes in just below 90 pounds. It makes a big difference in finger force.

For force measurement, you might make an artificial finger for a gram scale and press the guitar against the artificial finger reading the scale at the point the note sounds cleanly.

I hope you heal quickly.

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Peter Wilcox
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Re: Force required to fret a guitar string?

Post by Peter Wilcox »

John Clifford wrote: I wouldn't try to put a positive spin on your accident, but it might be an opportunity to actually learn better technique ...
Or take up steel guitar or dobro.
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Brian Evans
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Re: Force required to fret a guitar string?

Post by Brian Evans »

Ha! I actually got my lap-top Dobro out, tuned up my National lap steel, but I can't quite control a bar yet. I'll likely have some time to try to figure this out, met with my surgeon on Friday and apparently the nerve damage to my left hand is 50/50 going to be permanent. I fell and broke my neck, C-7 vertibrae, and apparently median nerve damage is kind of common with that, the median nerve controls down the back of the arm, so I have a very weak tricep muscle, and in the hand it controls the palm, a bit of thumb and first and second fingers. I can use them OK, just can't feel them yet they are very sensitive to touch, pressure, heat, cold. Which is counter-intuitive - numb fingers yet painful. The surgery was to take out the discs, and fuse C-6 and C-7, they screwed in a plate between C-6 and C-7. I also broke 6 ribs and dislocated two fingers on my right hand, they may need surgery too. Yay me... but it could have been a lot worse.

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Peter Wilcox
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Re: Force required to fret a guitar string?

Post by Peter Wilcox »

Wow! So sorry to hear that. Off a ladder or roof?
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Brian Evans
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Re: Force required to fret a guitar string?

Post by Brian Evans »

Down stairs around midnight in the middle of a power outage, but honestly I have zero recollection of the accident. I had a knock on the noggin hard enough to cause a hematoma, but not cause a concussion. I told the guys on the lap steel forum, when I asked about how to learn lap steel, when they heard I had C6 and C7 fused they said "obviously you need to learn C6 tuning..."

I was in my shop today, I looked at my bench and my tools, and my current project (a P-Jazz bass made of cherry a buddy of mine had from a tree he cut down), I wonder when I'll get back to it.

Freeman Keller
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Re: Force required to fret a guitar string?

Post by Freeman Keller »

Brian, that is incredibly bad luck and I'm really sorry to hear of your injury. But it got me thinking and no one has tried to answer your question, so I'll take a crack at it.

Some assumptions and some high school geometry. Lets say your scale length is 25.5, you are strung with generic steel strings and the one you are interested in has 25 pounds of tension. Lets fret at the 12th fret and assume the action is 0.080. The length of the string at that point is 12.75 so the angle about 0.366 degrees. Take the sine of that and multiply by the tension you get about 0.16 pounds of vertical component, since there are two sides of the triangle there would be a total of about 0.32 pounds of force, or a bit more than 5 oz.

Is that reasonable? Only way I know to check is to take the guitar that is on my bench, tune up the D string and put some objects on the string until it depresses to the fret. A fairly big socket (1-1/4 I think) worked pretty well - I threw it on my little postage scale and it weighed 8 oz.

That tells me I'm in the ball park - depending on a bazillian factors and assumptions it probably takes a half pound or less of pressure to fret a string.

As a lap slide/dobro/weissenborn player I encourage you to try it, get well and please be careful.

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Bryan Bear
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Re: Force required to fret a guitar string?

Post by Bryan Bear »

So sorry you have to go through this. I’m hoping for the fullest possible recovery!
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Rick Milliken
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Re: Force required to fret a guitar string?

Post by Rick Milliken »

Sorry about your accident, not good!

I've been wondering about fretless. I don't know if that would be easier or not and would be curious to hear. I've got arthritis in my hands and can manage the fiddle and a little banjo, but guitar is just not happening. (admittedly, strongly suspect technique too).

None of which deals with your original question though. Beyond what was suggested earlier, not much help on measurement.

Brian Evans
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Re: Force required to fret a guitar string?

Post by Brian Evans »

Freeman Keller wrote:Brian, that is incredibly bad luck and I'm really sorry to hear of your injury. But it got me thinking and no one has tried to answer your question, so I'll take a crack at it.

Some assumptions and some high school geometry. Lets say your scale length is 25.5, you are strung with generic steel strings and the one you are interested in has 25 pounds of tension. Lets fret at the 12th fret and assume the action is 0.080. The length of the string at that point is 12.75 so the angle about 0.366 degrees. Take the sine of that and multiply by the tension you get about 0.16 pounds of vertical component, since there are two sides of the triangle there would be a total of about 0.32 pounds of force, or a bit more than 5 oz.

Is that reasonable? Only way I know to check is to take the guitar that is on my bench, tune up the D string and put some objects on the string until it depresses to the fret. A fairly big socket (1-1/4 I think) worked pretty well - I threw it on my little postage scale and it weighed 8 oz.

That tells me I'm in the ball park - depending on a bazillian factors and assumptions it probably takes a half pound or less of pressure to fret a string.

As a lap slide/dobro/weissenborn player I encourage you to try it, get well and please be careful.
Thanks Freeman, that is right around where my gut told me it would be, so thanks for doing the math.

Brian

Mario Proulx
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Re: Force required to fret a guitar string?

Post by Mario Proulx »

I mangled my left thumb(literally tore the tendons that hold it, right off the bone) in 2016. The only thing I could play for a while was my telecaster with .009's, tuned a full step down.

Could you tune your guitar to an open tuning and use your entire hand, somehow, to fret it?

Clay Schaeffer
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Re: Force required to fret a guitar string?

Post by Clay Schaeffer »

Here's a crazy idea Brian,
If you lack the finger strength to press down the strings to the frets maybe you could make individual "bars" to fit on your left hand fingertips (like the metal picks people use on their right hand) and "stop" the strings that way. If you could perfect it, it might become a thing - the Evan's mini bar system. I know some people will put a slide on their little finger so why not the rest of them?
Sorry to hear about your accident. Hopefully you will regain most of what you have lost. here is an article that may be of interest:

https://www.sciencedaily.com/releases/2 ... 173806.htm

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Steve Sawyer
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Re: Force required to fret a guitar string?

Post by Steve Sawyer »

Brian - I'm not able to answer your question, but let me offer my heartfelt concern for what you're going through. So often, as a woodworker dealing with very sharp tools and spinning bits, plus developing some minor balance problems as I age, I worry about what I'd do if I lost some functioning in my hands. I'm fortunate (unlike my wife) that I have zero evidence of arthritis. I'm not a great guitarist, but am easily twice as good as I was even as little as five years ago. To lose that would be devastating. I really hope you recover fully and quickly!
==Steve==

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