Official Luthiers Forum!

Hi

Does having a straighter line from string to tuner make any noticeable difference to playing or any other advantages. .

Have got some sort of standard plans for a OM which are good looking but maybe a straight pull head won't look as pleasing ?

Cheers

I find a straight pull makes the strings feel less stiff. Especially while bending. I do both depending how I want the guitar to look.

_________________
http://www.Harvestmoonguitars.com

Same opinion as John, strings can feel a bit softer.
Sometimes for a "traditional" design guitar like an OM, a straight pull headstock can look a bit odd.
Especially an asymmetrically shaped headstock (as straight pulls tend to be) paired with a standard type bridge for example.

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Strings feel softer, intonation is less problematic.


You could go for a modern-shaped OM sized instrument. You either like the shape or you don't, but they sound fantastic!



Full plans for this model are in the book.

_________________
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

Thanks trevor... yours look great..

Beautiful guitars, Trevor!

Odd man out here... Many years ago on the olf I believed that I could hear slight tonal differences between of all things mind you the various bridge pin materials. One example was bone pins on one guitar sounded brighter to me.

Al C. rightly suggested to us that I may be correct but for the wrong assigned causation... Al suggested that even slight differences in mass over the bridge in this very sensitive region of the top was more likely what I was hearing. Al was right.

Fast forward - do straight string paths result in a softer feel to the strings?

My take on it remembering the causation thing that I learned from Al is this.

Seems to me that ultimately a longer string could feel softer than a shorter string because of a greater ability to stretch. Lots of folks notice this comparing longer scales to shorter scales.

I'm taken back to discussions about nut slots and how very important they are to cut well, low enough, no binding, able to handle perhaps one string gauge up, and my dislike for V shaped slots.

Seems to me that with well cut nut slots that will not bind angled string paths which result in a longer string would feel softer because there is more string to stretch.

Why then would straight string paths result in that softer feel? My 2:47 am post surgical fog would suspect that nut slots are more likely to exhibit desired attributes when they don't have strings entering and departing at different angles. Or, a slot having to deal with more angles has less room for error.

Back to nut slots might be fun to test this out with a test neck, case of beer, and a room full of Luthiers and a blind fold. Could also use one neck so as to counter material differences but with only two tuners installed.

To me, any performance differences between in line versus angled (other than differences due to actual string length per string above the nut) on an acoustic guitar depend a lot on how well the nut is made. In other words, a bad nut slot will let the string hang up even with an in line string path, whereas a good nut slot will let the string move back and forth even if the string path takes a slight left or right turn. So, for an acoustic guitar, I focus more on the aesthetic choice than any slight performance differences.

Electrics, especially those with a whammy bar, are a different thing. Same issue, but a much bigger deal.

Yes Trevor's guitar exhibits superior craftsmanship -- wonder if design and math parameters allow different head stock shapes?



My guess is that boutique builders and mass producers alike stay far away from double blinds tests in general --- they are well aware that the results just may not support their claims. Unfortunately sometimes some of us cannot hear or feel the math and science.

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/

I don't see how a string for any given scale length that is required to be under a certain tension to achieve a certain pitch could feel any different whether it's straight of slightly angled to the tuning peg unless it's as Hesh suggested, there is some friction in the slots. I like to angle the nut slot to the tuner post for that reason. On paper I suppose it makes a difference but you can actually feel it?

Trevor,
Is that bridge curly bloodwood? Has a cool look.

"Sometimes for a "traditional" design guitar like an OM, a straight pull headstock can look a bit odd."

The "snakehead" peghead can give a fairly straight string path and be very traditional.

This old discussion on TalkBass has some interesting photoshop work to put things in perspective.

http://www.talkbass.com/threads/i-must- ... th.588934/

The string consists of two lines, and regardless of which angle it takes toward the tuners, it is still just two lines meeting at one angle. It may bear down on a different part of the radius in the nut slot, and the final degree of the angle may be affected slightly, but in the end straight or angled both end up effectively "straight".

_________________
Eschew obfuscation, espouse elucidation.

That depends on how the nut slot is angled. With a straight slot and tuner not in line, you can get one bend at the neck side of the nut, and another bend at the headstock side of the nut. Different angles in different planes, thus more friction. That bass has such thick strings that they don't bend sharply, but the plain steel strings of a guitar definitely can.

But yes, with a properly made nut, it really shouldn't matter whether the tuners are in line or not.

When cutting nut slots, it helps me to think of the slot as a means by which the string takes a bend, rather than a sharp corner (or two sharp corners, one at the front and another at the back). The only sharp edge (and it is not all that sharp) I keep is the one at the fingerboard side. The other end flairs out a bit, and for the path across the nut, I want it to be curved, not flat. I try to start the nut file parallel to the fingerboard and the run of the string, then cut by curving it toward the tuning gear in question. I use a round bottom file that is a few thousandths larger than the string that will go in it, and I move the file around to try to keep the slot generously sized, especially on the tuning gear side.

The big difference between in line string paths and those that take a slight left or right turn is how much of the nut creates friction and opportunities for hanging up. In line string paths with generously sized nut slots tend to just have the string bearing against the bottom of the slot. Slight left or right turns inherently also cause the string to bear against one wall of the slot. Curving the slot, making it smooth, letting it flair on the tuner side, etc, all help toward making that not such a big deal. Again, for acoustic steel string guitars, a well made nut slot with either headstock design will not cause hang ups. A poorly made nut slot with either headstock design will cause hang ups. So I disregard all of this when designing a headstock and focus on how I want the guitar to look and what tuning gears I will use.

Yep ---- to my surprise a recent article in AG mag Dana Bourgeois mentions in his experience that those purchasing high end custom guitars are not solely, but mainly interested in the appearance of the guitar.

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/

Well, I would temper that view a bit, at least as far as my decision making goes. I'm not a professional builder, I have a long way to go before I try to sell anything I build, I am just building for me, and I don't think I am as shallow as the average high end guitar shopper.

I put aesthetics lower on the list of considerations when it comes to other guitar making decisions. This decision, whether to design a headstock around an in line string path, is more of an aesthetic choice, because I see the nut work as leveling the playing field in terms of performance.

Keep in mind that the high end buyer expects outstanding fit and finish --- excellent play-ability, set-up, intonation etc. are basic given features or else the makers would not be in the high end arena in the first place.

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/

I agree with David Collins on this: there has to be an anlge at the end of the fretboard, and should be only one. If it's well done it will work well. What the string looks like in the plan view should not matter. If you look at a lute head on the strings pull 'straight' from the bridge to the pegs, but from the side that make close to a right angle. If the nut's made right they will tune fine.

I would think the 'softer' feel has to come from having more 'backstring' between the nut and the tuner. This should be amenable to objective testing.

The force applied to the nut by the string, and hence the frictional force between string and nut which resists sliding, is related to the angle the string makes transitioning from the neck to the headstock.
A well cut nut avoiding sharp transitions will help, but this frictional resistance remains.
With say a 50's Gibson which had a 17 degree headstock and widely splayed G and D the effective angle is greatly increased and the resultant friction leads to the common tuning problems on these strings after bending.

Thanks for the kind words, Gentlemen. It certainly constrains where you can put the tuners if you want to go absolutely straight string pull, but I've seen quite a few permutations from people who have built from the book and made the headstock their own. If you go 6-a-side (which I've never preferred myself on an acoustic) there's a whole stack more options.
Thanks. Figured Aus. Blackwood, same as the rosette and binding.

There's always going to be some friction in the slots. What makes the difference is how much.

When I first started with nut compensation, I didn't really know whether the string slid over the nut or not when it was fretted. It's a pretty difficult thing to measure. What I did was a statistical analysis of about 18 or so guitars I built, all with straight string pulls. Roughly half were done with the assumption that the string "locked" at the nut and so the string stiffness (for working out the compensation) was governed by the nut-to-saddle distance. The others I assumed the string slid, figuring out the string stiffness from the tuner-to-saddle distance. For each guitar I measured the intonation error, all strings, all frets, to see which came out best. The guitars with the compensation worked out with the tuner-to-saddle distance had statistically better overall intonation, which convinced me, at least, that the string moved over the nut when fretted.

So the task then is to make sure that the friction is consistently minimised over the nut (or locked, if you want to take the other approach). I went the low friction route. Now many guitars have straight string pulls on at least some strings, but usually at least two fairly "bent" ones. But as David points out...

... the strings are always a "straight" pull if you choose the right plane to look at them in. However, most of us are cutting nut slots with straight files and if you file a nut slot on a splayed string to give a single in-plane angle, it is inevitably quite an abrupt angle, because it is difficult to get a smooth approach and exit to the "corner". And that is where the issue arises that no one has yet raised (but Jeff hinted at).

When a string is bent around an abrupt corner it will plastically deform the string, which takes a force, which is not returned as it would be in an elastic bend. So when a string is fretted, if it is going to move it has to plastically bend a small part of the string going into the curve and unbend a small part of the string coming out of the curve, which is all non-returnable force that looks like friction (on top of the F= mu * R static friction of the string over the nut). The force required to bend and unbend the string is proportional (iirc) to the curvature, which is the reciprocal of the radius. So as the radius gets smaller, the force required for the bend/unbend goes hyperbolic rapidly. This is one reason why knots work, and why a bend on the end of a truss rod will effectively lock that end in the heel; and approaching the physics from the opposite direction, it is why tension levelers work for straightening out sheet steel. A 0.016" B string goes plastic at bend radii tighter than about 0.5". So any bend over a nut with a radius of less that 0.5" is going to give at least some problem, and as the bend gets tighter the problem gets rapidly larger. If you go for a straight string pull, you have a plane of curvature over the nut that can easily be shaped with a straight nut file and so the bend radius and resulting string curvature can be more easily managed, which means you can get little or no bending losses. Doing that is much harder with splayed string pulls. Hence my comments above:

_________________
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au