Re-stringing & Machine Heads - Practicalities

jaymenonjaymenon Frets: 804
edited February 2019 in Making & Modding

A couple of years ago a friend of mine who is a brilliant guitar technician showed me how to restring conventional tuners and I'm no longer convinced that locking tuners save time.

Furthermore since the post is wasted, the coils / wraps of the string tend to move towards the narrowest part of the tuner post (the waist) forming a 'compression wrap' that greatly exceeds any lock that a locking machine head can provide. A traditional machine head is a seriously impressive work of engineering.

I can however, completely see the logic behind locking machine heads: fewer windings of the string around the tuner post and therefore more likelihood of the string coming back in tune after depression of the tremolo arm.

One unfortunate practicality however, with lockers is that if you have a neck on which the truss rod adjusts at the heel, (requiring taking the neck off in order to adjust the truss rod), every time you do so, it's almost guaranteed that you will break one or two strings...

It would seem wise to restrict lockers to necks with headstock end truss adjustment.

A couple of excerpts from Eltham Jones' website (Edge Guitar Services) that are very interesting:

Conventional (non-locking ) tuners fall into three broad categories

1. Waisted spindle with a central radially bored eyelet

2. Split post, axially bored (sometimes called the Safe-T post) as found on vintage Klusons

3. Parallel post, radially bored eyelet.

The last of these categories includes legacy designs found on early guitars, tuners for classical guitars and for slot-headstock steel strung guitars. 

One of the most commonly taught methods of restringing involves passing the string through the eye of the tuner spindle the hooking it back underneath the string so that it is locked between the string and the spindle. you will find this technique illustrated in almost every book on guitar playing and maintenance, on the little flyers placed in the cases of new guitars, magazine and internet articles...

This method is sometimes called the Nashville wrap I am told but it is a really, really bad way of stringing a steel strung guitar!

Granted there are occasions when it has its uses; it's the only technique that works for nylon strung guitars and on some early tuners with parallel spindles but on modern tuners with waisted profiles coil-compression techniques such as the piano wrap offer better stability and security and less risk of string breakage.

I call the "Nashville" wrap the lock wrap because it effectively locks the free end of the string to the tuner spindle. Users believe that this makes the string more stable but in fact it doesn't; it simply makes it harder to remove the string when you need to change it! 

It also reduces contact between the inside of the coil and the tuner spindle, limiting friction hold and introducing a point of stress where the coils cross over it.

Modern tuners are designed with a concave radiused profile which is intended to enhance coil compression by causing each coil to seek the narrowest part of the radius as it tightens. Subsequent coils slide into place alongside and are forced into contact by the radius so that the string is clamped effectively on perhaps three or four sides as well as the inside surface of each coil. This means that a top E with four wraps is clamped tightly by self sustaining pressure over approximately a 100mm length. Beat that. Sperzel!

tuner wrap from the side

The other disadvantage of the lock wrap is that having locked the string onto the tuner the only way to increase the number of wraps is to laboriously wind the string on by cranking the tuner. Not only is this time consuming but it increases wear and tear on the tuner's gearing.

What follows is a brief description of the piano wrap. This has the advantage of:

1. A secure and stable wrap which takes advantage of the geometry of the tuner

2. Reduced wear and tear on the tuner, and the spindle

3. Speed and ease of application

Although the technique can take a few tries to get it right, once you have mastered it you won't ever fear restringing your guitar again. 

With the guitar on its back and the neck supported, draw the string tight and lay it alongside the tuner spindle on the side opposite the button.

Wrap the string around the spindle at least once, then push the free end through the eyelet.

Grasp the free end and pull it tight so that the coil compresses against the spindle. The free end should go over the coil and not under or through it.

Pull the free end back against the spindle in the direction opposite to that of rotation. This creates the important Z-Lock

Wind the tuner to bring it up to pitch and give the string a tug to consolidate the coil.

You should aim for a wrap about 1/8"(3mm) deep, just enough to cover the eyelet and trap the free end against the top of the eyelet.

The picture belowshows a cross-section of a standard tuner through the eyelet.



tuner wrap from the top


The string is pulled tight and wrapped around the spindle as shown by the arrow.

The free end is passed through the eyelet and hitched back against the opposite edge of the eyelet to create the important Z-lock which prevents the string from disengaging while it is being brought up to tension.

The Z-lock is basically a torque lock. As the string comes under load, tension in the string pulls the near end of the Z-lock against point A. 

The straight section of the string housed within the eyelet pivots on the edge of the eyelet at A, rotating as shown by the red arrows, pulling the distant end of the Z-Lock against the opposite edge, B. This prevents the string from slipping through the eyelet as the string is brought up to tension. 

The Z-Lock only works when the string is under load so when the string is removed it simply slides through the eye unimpeded.


Although I haven't discussed the complications of locking tuners here the Z-lock is an important enhancement for any tuners with internal locking pins (as opposed to the far superior torque locking types as found on the Gotoh Magnum Lock or the early PRS locking tuners) as the clamping area of spindle-pin lock tuners is inadequate on its own. 

How the Z-Lock works

tuner wrap from the top

CORRECT
an illustration of the z-lock done correctly

A common error, shown below, is to hitch the string in the wrong direction so that the string forms a "D" rather than a "Z" where it passes through the eyelet. This renders the lock ineffective. 
an illustration of the z-lock done incorrectly
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Comments

  • ICBMICBM Frets: 71960
    jaymenon said:

    One of the most commonly taught methods of restringing involves passing the string through the eye of the tuner spindle the hooking it back underneath the string so that it is locked between the string and the spindle. you will find this technique illustrated in almost every book on guitar playing and maintenance, on the little flyers placed in the cases of new guitars, magazine and internet articles...

    This method is sometimes called the Nashville wrap I am told but it is a really, really bad way of stringing a steel strung guitar!

    Granted there are occasions when it has its uses; it's the only technique that works for nylon strung guitars and on some early tuners with parallel spindles but on modern tuners with waisted profiles coil-compression techniques such as the piano wrap offer better stability and security and less risk of string breakage.

    I call the "Nashville" wrap the lock wrap because it effectively locks the free end of the string to the tuner spindle. Users believe that this makes the string more stable but in fact it doesn't; it simply makes it harder to remove the string when you need to change it! 

    Sorry, but this just isn't true at all. I've been stringing guitars exactly like that professionally for about twenty years, and I've *never* broken a string doing it as far as I can remember. Nor is it difficult to remove the string, you just give it a sharp tug once you've unwound it.

    For me, it's the quickest, most stable and best method of stringing a conventional post. It's both quicker and considerably more stable than the 'over and under' method I used before, and will not slip... ever. It's also usually possible to fully slacken the strings to do something like a truss rod adjustment without breaking when you tension them again, providing you're careful to make sure they come tight in the same position.

    "Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski

    "Just because I don't care, doesn't mean I don't understand." - Homer Simpson

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