Sunday, 11 November 2007

More beating around the bush

As I describe here, things have slowed down considerably since this summer. It quite typical to me (and probably many others), that planning is easy, but when I get to the point of actually making the things I've been planning, the progress goes down.

In the meantime, until I get the motivation for taking the T-beam guitar some steps further, I might as well plan even more. ...and consider alternative methods for future guitars.

One of the issues I prefer to think of is the possible tuner systems for headless guitars. On Building the Ergonomic Guitar, there's much discussion around how to make a headless tuner system. See e.g. here and here.

I'd like to add another possible principle to the discussion: Using a bicycle brake cable tensioner. It is normally used to tighten the brakes of a bicycle by turning the nut with the rubber ring seen here (click the images for a better view). Since the threaded, cylindrical part of the tensioner has a flat area which fits a hole of the same shape in the brake arm, it will not turn (but only slide) when the nut is rotated. On a bicycle, as seen here , the outer cable stops at the tensioner, and the inner cable goes through it and is fastened on the other arm of the brake.

When using it as a guitar tuner, the string passes through the cylinder (the part with the outer thread) and the total of six tuners/tensioners should be mounted in a brace with six holes of the shape that allows the cylinders to slide, but not to rotate . By turning the individual nuts (the part with the rubber ring), the strings are tuned.

Of course, there's no need to use dedicated bicycle brake cable tensioners. It might be better to make the tuners from pieces of threaded rod with a hole drilled through them plus some knurled knobs such as these . Choosing three knobs of each of the two types shown in the picture would even allow for a staggered placement of the knobs, in turn allowing bigger knobs than with an in-line configuration.

I'd expect it to look like this.

It seems to me to be one of the simplest solutions to the problem of making cheap, accurate and reliable tuners for a headless guitar. I may have overlooked some problems with the principle, so prototyping must be the next step. Once I've finished the T-beam guitar.


RayD said...

Nice idea. The only negative I see is avoiding torsional loads on the strings. You'd need some way to keep the string from twisting as you're tightening.


Alexander Gorm Øst said...

Hi Ray

There will be no torsion on the strings due to the flat area on the thread of the cylinder. The hole for the cylinder (see my drawing of the brace) matches the cross section of the cylinder (which isn't actually a cylinder due to the flat area) and keeps it from turning when the nut is turned.

/Alex said...
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G L Wilson said...

Any more updates?

I keep checking back just in case.

Alexander Gorm Øst said...

No, nothing at the moment. I've been thinking about how to make a locking nut with slotted screws for adjustable saddles for the guitar. Apart from that, things are going slowly. Easter holiday is coming up - that might be a chance to get some momentum on the build.

I bought a drill press a couple of weeks ago. Not that I need it for the next steps (which above all is about deciding on the final shape and making a routing template). Still, having it standing ready might somehow inspire me ;-)

Thanks for asking.

Jean Paul said...

Great project Alexander!
Your thoughts on alternative tuners
caught my attention, I had the same idea with the bicycle cable tensioners for my bass project but think it is a bit flimsy. Your blog starts with this other idea which i think is very interesting indeed. I would like to motorize it so you can autotune the guitar.
Jean Paul Later (laterrebass.blogspot)

Alexander Gorm Øst said...

Hi Jean Paul

Thanks. I'm still very enthusiastic about the T-beam though I haven't actually built anything yet.

I think the cable tensioner principle works best if you don't use actual cable tensioners, but make them from other components (threaded rods, knurled knobs, etc). There has been some discussion on the topic at

Ola Strandberg is constructing integrated tuners and bridge using a similar principle. These are single string bridges - which are mostly seen on basses, so it might be useful inspiration for you.

That are some great looking basses on your blog. I really like the way that the fingerboard extends down the body. All the way to the bridge, I suppose.

Alexander Gorm Øst said...

The last part of the link above got snipped. Here it is on two lines:

Terry said...

Very interesting tuner design! I'm eager to see what a real prototype would look like. As I understand your design with the knurled knobs, the threaded rod would extend out of the end of the knob as you increase the tension. Is that correct?

Alexander Gorm Øst said...

Yes, the threaded rod (which I've seen referred to as a _plunger_) pulling the string would go through the knurled knob - at least if you keep to a layout as those of the brake cable tensioners (in which case it would go through the knob even before you started tightening the string).

Of course, if you used a very long knob, it could contain the whole end of the plunger. Ola Strandberg ( makes tuners of a similar principle where the knob is closed and the plunger hidden. Plus, he actually _makes_ things whereas I mostly talk about what I'd _like_ to make ;-)

I've bought a cheap guitar to test prototype bridge, nut and tuner designs on, so perhaps I'll make a prototype of it. I don't think it will be very soon though, as there's a lot of other things I'd like to try out as well.

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