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Wobbly Machine Heads
http://mowrystrings.luthiersforum.com/forum/viewtopic.php?f=10137&t=46091
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Author:  Fret [ Mon Jul 27, 2015 2:20 am ]
Post subject:  Wobbly Machine Heads

http://images.guitarbitz.com/images/products/1307719790-94523900.jpg
This is a Project Telecaster build from a $170 Squier which has some very nice looking tuning keys that wobble and rattle with the strings off. Of course they still wobble and float around when strung causing tuning issues. The machine head has a very loose fit inside the bushing.

I was able to fix the wobble by shimming the bushing to machine head gap

Problem solved completely? I don't know. You see I used paper to create a shim the size of a postage stamp which I scrolled up inside the bushing and slipped the bushing over the machine head. I found that the paper BB&T uses for their bank statements was the perfect thickness. It has no wobble now but does the paper shim cause a loss of sound? Does the paper shim muffle the sound? I'm splitting hairs here I know but I'm looking to get the best I can get out of this project as well as keep costs low. Why buy a Chinese guitar and then spend a mint fixing it up? Why not learn to debug the issues you commonly see with cheap guitars?

If I could make a brass shim the exact thickness of the paper shim I think this "fix" would be a very professional solution. My goal is to use as much of the original hardware as possible by modifying the Chinese parts that the guitar came with. These tuning keys look great but left as they came the guitar was tough to keep in tune. If I could make a brass shim I think these Chinese tuning keys would sound as good as a set of Grovers. However, I want the sound Grovers can give.

I know they sell brass shim sheets but do they make various thicknesses?

Can I buy brass shim strips the thickness of the paper I used? Has anybody done this? The answer most project builders have for Chinese machine heads is to buy new tuning keys.

OR?

Is the paper shim a good solution?

Author:  Chris Pile [ Mon Jul 27, 2015 8:33 am ]
Post subject:  Re: Wobbly Machine Heads

I don't see a problem with the paper for a shim. After all, it's wood, too.

Author:  Lonnie J Barber [ Mon Jul 27, 2015 9:21 am ]
Post subject:  Wobbly Machine Heads

I agree Chris through the years many a shade tree mechanic...... Er.......... I mean Luthier has used paper to shim up something or other on their guitar. You know those little tiny scissors your wife uses to trim her cuticles? Their great to trim off any access. You can barely even see it. :)


Sent from my iPhone using Tapatalk

Author:  Fret [ Mon Jul 27, 2015 1:55 pm ]
Post subject:  Re: Wobbly Machine Heads

Perhaps I will leave the paper shims then.

These tuning keys look as good as Schallers or Grovers but they are better suited for the trash can without the machine head shims.
It cost the same to drill the wrong size hole as it does to drill the correct size. Quality vs garbage.
Why did the Chinese drill the wrong size hole I wonder?
Buy American when possible. Lesson learned.

Author:  Burton LeGeyt [ Mon Jul 27, 2015 2:23 pm ]
Post subject:  Re: Wobbly Machine Heads

You can buy precise brass shim stock, a place like McMaster will have it. As was already said, though, paper is probably fine.

Author:  Fret [ Mon Jul 27, 2015 2:31 pm ]
Post subject:  Re: Wobbly Machine Heads

Burton LeGeyt wrote:
You can buy precise brass shim stock, a place like McMaster will have it. As was already said, though, paper is probably fine.


One day i'm going to shell out on a selection of various brass shim thicknesses. As a shade tree luthier I can't justify buying a bunch of different sizes at $15 a roll. I have worked on two of my guitars recently where I found myself needing a precise shim thickness and I ended up using paper.

Author:  Burton LeGeyt [ Mon Jul 27, 2015 3:05 pm ]
Post subject:  Re: Wobbly Machine Heads

Actually, a variety pack is a common thing, and very handy. I have one in steel and brass just in case.

See the bottom of this page:

http://www.victornet.com/subdepartments ... /1010.html

Author:  Fret [ Mon Jul 27, 2015 3:43 pm ]
Post subject:  Re: Wobbly Machine Heads

Burton LeGeyt wrote:
Actually, a variety pack is a common thing, and very handy. I have one in steel and brass just in case.

See the bottom of this page:

http://www.victornet.com/subdepartments ... /1010.html


Thanks I could benefit with a steel assortment which would do anything brass would do. Check the prices on the exotic metals. Like buying jewelry. LOL!

While hunting shim stock for the tuning keys I had tried thick aluminum foil but it was slightly too thin and too thick when I scrolled it twice around the machine head.

The interesting thing I learned is that paper is great to test what thickness fits. It costs nothing to pick the wrong thickness ten times.

Ive also found myself in situations where metal shims could have added quality to the job.

Author:  fumblefinger [ Mon Jul 27, 2015 11:02 pm ]
Post subject:  Re: Wobbly Machine Heads

Fret wrote:
http://images.guitarbitz.com/images/products/1307719790-94523900.jpg

It has no wobble now but does the paper shim cause a loss of sound? Does the paper shim muffle the sound?

If I could make a brass shim I think these Chinese tuning keys would sound as good as a set of Grovers. However, I want the sound Grovers can give.[/b]


So I'm getting a bit lost. I thought the vibration transmission to the body pretty much ended at the nut/fret. I mean, if you've fretted a string you have your finger dampening anything between the fret and the tuner. How much vibration still goes to the end?
Help educate me.

Author:  Fret [ Tue Jul 28, 2015 2:41 pm ]
Post subject:  Re: Wobbly Machine Heads

fumblefinger wrote:
Fret wrote:
http://images.guitarbitz.com/images/products/1307719790-94523900.jpg

It has no wobble now but does the paper shim cause a loss of sound? Does the paper shim muffle the sound?

If I could make a brass shim I think these Chinese tuning keys would sound as good as a set of Grovers. However, I want the sound Grovers can give.[/b]


So I'm getting a bit lost. I thought the vibration transmission to the body pretty much ended at the nut/fret. I mean, if you've fretted a string you have your finger dampening anything between the fret and the tuner. How much vibration still goes to the end?
Help educate me.


Anything and everything that touches that string is what determines tuning. Simply because a string runs atop the nut doesn't erase what is happening at the machine head. If the machine head floats around even just a microscopic amount then that is affecting the length or dampening the vibration of the string and thus is connected to tuning. You can not overthink what goes into a guitar staying in tune. Everything from the ferrules to the machine head is involved in tuning. Literally everything. You can't just look a tree. Look at the forest.

Author:  fumblefinger [ Wed Jul 29, 2015 12:41 am ]
Post subject:  Re: Wobbly Machine Heads

Sorry, I still don't get it. "loss of sound" and "Does the paper shim muffle the sound?" I don't understand.

http://newt.phys.unsw.edu.au/jw/strings.html "The string on a musical instrument is (almost) fixed at both ends, so any vibration of the string must have nodes at each end. Now that limits the possible vibrations." Fixed length. I.E. the saddle and a nut/fret.

Point being it is fixed. With 16 to 19 lbs of force on each string, the tuner will set against the hole at the closest point in line with the string, relative to the nut. There shouldn't be any variation in the tuning of the string, once it's brought up to pitch. Unless you force the tuner around in the hole. And since it's past the vibration of the string, it should have minimal effect on the sound.

http://www.frudua.com/guitar_strings_tension.htm Note the "The portion of strings not directly involved in vibration in red corresponds to a 15% / 30% of the total." They are talking about the portion from the saddle to the stop bar and the nut to the tuner. The thrust of the article is how the break angles affect bending strings. But you'll notice that they never vary from the point of the string vibration occurring between the saddle and the nut. (or the fret).

So it would seem to me the articles all say that the vibration of the string occurs between the two primary contact points, the saddle and the nut/fret. If there is no vibration beyond these, how much can they affect on the sound?

I'm not trying to be a smart _ss, I just don't understand how the "dead" part of the string has that much effect on the sound. My physics background is flailing at me. I know that people rave about the better stop bars, and I'm sure there is something to it. That's why some guitars have string through body fastening.

But at the end of the day, the tuner being a bit sloppy in the hole shouldn't produce any significant transmission loss.

Author:  Fret [ Wed Jul 29, 2015 12:51 am ]
Post subject:  Re: Wobbly Machine Heads

If you steal a Chevy in Texas and drive it across the border to Oklahoma the man will bust
you there too.

Image

See those two string trees? They are there to stop harmonic transmissions that go past the nut. Tuning and harmonic issues do transverse the nut. Some people use foam or tape wrapped around the strings in the head stock area to stop transient harmonics so perhaps that proves you to be technically correct.
Is it possible that a paper shim around the machine head can reduce that bright brassy ringing tone a guitar should have? Yet a string tree doesn't hurt a guitar's sound or tuning. That question is what started this whole thread.

I have you and several others who say the paper shim is a technically correct repair for a wobbly machine head. So I'm leaving the paper shims in place unless I learn otherwise. It just seemed cheesy to me. Heck, maybe I did something smart by accident?

The thing is though: I've thought about this for a week.

Author:  fumblefinger [ Thu Jul 30, 2015 11:44 pm ]
Post subject:  Re: Wobbly Machine Heads

And all this time I thought that string trees were a Band-Aid for Fender's headstock angle (or lack thereof). :D

On reflection I'm wondering if the answer is yes to both sides of the question. I can definitely see how a wound string could carry the vibrations through the core, even though the outer windings may be dampened at the nut But I think an un-wound string would be almost completely dampened at the contact point.

OK, down to the guitar corner to do some experimenting.... beehive

Author:  Fret [ Fri Jul 31, 2015 1:16 am ]
Post subject:  Re: Wobbly Machine Heads

You can write a book on what goes on past the nut over the head stock. String trees are dong all kinds of stuff both good and bad. Ive only used string trees to stop harmonic hum on the D string that the pickup coil amplifies.

String trees get used to keep strings sitting in the nut. They cause extra friction that players who bend strings notice. Lotta stuff string trees do. If you can do without them you should omit them because of the bad stuff they do.

Stuff is going on past the nut is what I was saying.

Author:  Hesh [ Fri Jul 31, 2015 6:51 am ]
Post subject:  Re: Wobbly Machine Heads

Fret wrote:
If you steal a Chevy in Texas and drive it across the border to Oklahoma the man will bust
you there too.

Image

See those two string trees? They are there to stop harmonic transmissions that go past the nut.


Actually no, string trees are to increase break angle often for Fender style necks where Leo (Fender) was a master of manufacturability but in his efforts to control costs for neck blanks and combined with the head stock design the break angle was/is insufficient. We see this more pronounced with the G string where that second string tree does not exist, which is most of the time. My strat has dual string trees and that is one of the reasons why I selected that model.

A work around for the G strings that do not have string trees is to wrap the entire string on the post so that the windings go way down toward the head stock face thusly increasing break angle over the nut.

String trees may have some dampening past the nut but the predominate function has always been to increase break angle. Otherwise and if dampening post nut vibration was the primary function why do we not see them on other designs? Because they are not necessary say with a G*bson head stock because the head stock has set back to it increasing break angle.

As for your sloppy tuners shims, metal or paper, etc. is no substitute for replacing the tuners. You are right that tuning stability is very important and to tighten up all things related decent tuners or even cheap tuners that don't have a lot of slop in them are important.

Author:  Hesh [ Fri Jul 31, 2015 6:54 am ]
Post subject:  Re: Wobbly Machine Heads

fumblefinger wrote:
And all this time I thought that string trees were a Band-Aid for Fender's headstock angle (or lack thereof). :D

On reflection I'm wondering if the answer is yes to both sides of the question. I can definitely see how a wound string could carry the vibrations through the core, even though the outer windings may be dampened at the nut But I think an un-wound string would be almost completely dampened at the contact point.

OK, down to the guitar corner to do some experimenting.... beehive


You thought right!

Author:  Fret [ Fri Jul 31, 2015 7:36 am ]
Post subject:  Re: Wobbly Machine Heads

Hesh wrote:

As for your sloppy tuners shims, metal or paper, etc. is no substitute for replacing the tuners. You are right that tuning stability is very important and to tighten up all things related decent tuners or even cheap tuners that don't have a lot of slop in them are important.


I reached the cutoff point cost wise and I'm not spending anymore is why I didn't replace tuners but I think I'm happy with the tuners as they are shimmed now. In fact the sloppy tuners were the best quality of all the hardware on this Squier. Squiers are pot metal city. They even had pot metal zinc Allen screws in the saddles. I was pretty ticked seeing that.

Author:  Fret [ Mon Aug 17, 2015 5:27 am ]
Post subject:  Re: Wobbly Machine Heads

UPDATE

I switched from paper to aluminum shims in the wobbly machine heads. I found a lid from a peel off Sardine can that was perfect. I wound the aluminum around a big nail to get it to scroll around the tuner pegs inside the bushing and simply cut it to size with scissors.
I had been collecting strips of aluminum like a mouse in my search for the correct shim thickness.
http://www.fender.com/squier/guitars/telecaster/affinity-series-telecaster/0310200502.html#sz=12&start=1

Side Note
This guitar is cheezy Chinese Tele despite looking very nice. . I had trouble getting it to intonate and tune and stay in tune.
There is zinc pot metal in the saddles and tuners. I had to change the Allen screws because they were
zinc and poorly machined. They'd back out while I played it. Quite incredible. I'd never seen that happen. The two mods performed enabled me to keep the tuners and saddles(aluminum tuner shims and steel Allen screws for the zinc saddles). The guitar intonates and stays in tune pretty well now.
The only hardware I changed was the crap pickups. I stuck in a set of Texas Specials.

Would I do this again? No. I'd get a cheap Mexi next time but for a little over $300 total I have a great playing new Project Telecaster that stays in tune and sounds fantastic. I can now experience what a Telecaster is with what little money I had to spend.

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