Friday, 10 July 2009

Coarse Tuners part 2

As described in an earlier post, I've tried to make a compact set of coarse tuners to go with the fine tuners on my Schaller 456 fine tuning bridge, so I could reduce the headstock and loose the big and heavy traditional tuners. The earlier attempt in the form of a locking nut wasn't succesful, but now I think I'm on to something.

I've installed my own coarse tuners, each consisting of a blind screw, a T-nut and an allen nut (a.k.a. an internal wrenching nut). In the blind screw, a hole is drilled for the string to go through, just like the peg of an ordinary tuner.

To tune up the guitar, you turn the blind screw clockwise with an allen key until you reach the approximate tone. Then you fasten it by tightening the allen nut on the back of the headstock. The rest of the tuning is done with the fine tuner at the bridge.

One of the beautiful things about it is that when you tighten or loosen the string by turning the set screw, the height of the string over the fingerborad stays the same, since it rests in the screw's thread. And the pull of the string tightens the allen nut against the T-nut, securing the string even more.

The best thing about it is, it seems to work perfectly. And it's much smaller and lighter than ordinary tuners, so it's a good solution if you want to build a headless guitar - or convert an existing guitar to one. You'll have to leave a little bit of headstock for the T-nuts, but that's not much. And you might want it anyway to stop your fretting hand from sliding off the neck.

On my own guitar I've mounted the tuners on the very end of the headstock. The reason is that I'll be using the other sections of the headstock for experimentation with alternatives to the T-nuts. A set of threaded inserts and a brass plate with threaded holes are some of the things I want to try. Next experiment will probably be threaded inserts mounted on the next section of the headstock. And I imagine that when I have reached the last section of the headstock, next to the nut, I'll know which of the solutions I prefer.

Drilling the string holes in the blind screws was a pain. I only got two made before I had dulled or broken my drill bits. I'll have to buy some new ones and do it right. That's the reason why the remaining four strings in the picture go to traditional tuners.

Btw, I imagine that if you add some loctite or similar to increase friction, you might be able to do away with the allen nut. Afaik, there also is a substance called "peg dope". I have to get some and try if the tuner can hold the string without the allen nut.


guitarworks said...

Alexander! I have not checked your site for ages, but am very pleased to see you are making progress. I love your coarse tuners! Did you see my design?
Your's is simpler though - great work!

Anonymous said...

These designs could not have been better. I just wish there's another one that looks entirely like Van Hallen's style guitars.


Alexander Gorm Øst said...

Thanks Ola

Yes, I saw your coarse tuners and was amazed at their sophistication and how well they look - and how nicely they visually fit your other components. But I was also concerned about what seems a very delicate mechanism. Did you make a version with a stronger spring as you mention on your blog?

I read that you're going to visit Rick Toone in August. If you run out of things to talk about (not likely, I imagine), please figure out a way to drill holes in blind screws ;-)

Alexander Gorm Øst said...

Someone asked about the purpose of the allen nut, if it was only there to tighten the blind screw. I can't find the comment, but it was a good question, so here's the answer:

Yes, that's the only purpose of the allen nut. I am going to try to do without it and instead add something sticky that increases the friction of the thread. I'm not quite sure what to use. Peg dope is supposed also to lubricate in some way (don't ask me how it can lubricate and increase friction at one time, but that's what they say), and that's against the purpose. I've looked at loctite's website, but it seems to me that all their products for securing threads are ones that cure and harden. Meaning that it has to be cracked loose if you want to readjust the coarse tuning. I'd like something that stays sticky. Perhaps syrup would do.

Joshua Allen said...
This comment has been removed by the author.
The Dude said...

I would suggest Teflon tape maybe, but it might tear after so many uses.

Alexander Gorm Øst said...

Teflon tape could be worth a try. Teflon is slippery, but if packed tight, it might give enough friction. I don't think tearing will be a problem. The coarse tuners aren't used much: each time a new set of strings is mounted plus only a couple of times for each set of strings.

I'll try it out next time I change the strings. Thanks for the suggestion.