Saturday, 28 July 2007

Making my own T-beam

As mentioned earlier, I've had an unexpected hard time finding a suitable T-beam. There are lots of them available, but none wide enough for me to make holes for the pickups without intersecting the top flange completely.

For now, I have given up on finding a T-beam, and I will be making my own. It will consist of a 120 mm (4.7") wide and 10 mm (0.4") thick flat bar of AlMgSi0,5, also known as 6063 Aluminium, which will act as the top flange of the t-beam. The vertical part of the T will be a 30 x 10 mm (1.2" x 0.4") AlZnMgCu 1,5 (aka 7075 aluminium).

6063 is a fairly soft aluminium which should make it fairly easy to shape the neck, make holes for the pickups and make a recess where the bridge will be (otherwise the bridge will be too high). I've heard that it is so soft that it can be difficult and "gummy" to shape, but I could't get a piece of 6061 Aluminium, which was my preferred alloy. We shall see how much of a problem it'll pose.

7075, on the other hand, is very hard and strong, which is nice because the vertical flange will have to withstand the pull of the strings. It will be more difficult to drill, saw and file, but fortunately, the shaping needed on this bar is much simpler than on the top one.

I plan to join the two bars with screws and two component epoxy adhesive.

I ordered the bars yesterday, so now it should only be a matter of days before I can get going. All in all, I'm quite satisfied with the solution. I'd have preferred a "real" T-beam, but this solution allows me to have a stronger alloy where it really matters: The bottom flange.

Friday, 13 July 2007

A different tuner system for headless designs

The guitar I'm planning at the moment might be the first in a series. If it turns out well and the building process is fun (the planning sure is), I expect to build another one. And probably then another. And so on. If the guitar turns out sounding horribly and/or the building is hell, I guess that'll be it. But that hasn't happened yet, so for the moment, I'm happily planning features for future models.

As mentioned earlier, I've settled for the Schaller fine-tuning bridge for the first version of the T-beam. This will avoid a number of potential problems and make the construction more straightforward. I am fine with that. For the next version, however, I have a sleek and efficient tuner design in mind.

The system consists of six arms mounted with one end on a shaft below the top flange of the T-beam. Approximately two thirds to the far end from the shaft, the string attaches to the arm (after going over the bridge and through a hole in the top flange) and is secured either by its ball end or by a screw. The latter solution will allow me to use the ball end at the nut, eliminating the need for a locking nut.

For each arm, a screw is mounted through the top flange. The end of the screw presses down on the arm. Tightening the screw results in pressing down the arm and tightening the string. If the aluminium is strong enough, the threads will be made directly in the top flange. If not, I'll insert some threaded steel or brass bushings.

The picture shows the guitar with one arm only. It is supposed to have six - one for each string.

By selecting steeper or shallower thread for the screws or various lengths of the arm, one can decide how much adjustment is needed for a given change in tuning. An obvious idea is to have a greater ratio for the thicker strings, since it takes more force to tune them.

My rough measurements say that it takes about 4 mm (0,16 inch) to tune the string an octave. That means that there is lots of room for the travel of the arm, even with a relatively thin body.

The idea goes well with using a T-beam, since it uses the top flange for mounting the arm and screw. But actually, I think it can be made as a modification for a wooden guitar as well - all you have to do is route out a cavity for the tuner system and mount it all on a steel or aluminium sheet.

Tuesday, 10 July 2007

Alternatives to the T-beam

I've tried quite a lot of places to get the crucial component, the T-beam. It is more difficult than I originally expected. I've tried a couple of scrap metal dealers and the leading Danish metal distributor. Plus a couple of web-based stores. No success yet. It's quite disappointing, especially since I thought that obtaining the T-beam would be the easiest part of the project.

Until I find the T-beam - *if* I ever do - I've been contemplating other shapes of aluminium for the "spine" of the guitar. One possibility is an aluminium flat bar, 100 mm wide and 20 mm (approximately 4 and 0,8 inches) thick. With it, I could make the neck in aluminium only (as opposed to the T-beam version, where the neck sides are wood).

It would look clean and probably give a more pure aluminium sound. It would also be very thin. But it would imply a much larger amount of metalworking than I'm comfortable with. Plus, it would be quite heavy. Good thing it's headless, otherwise it would probably be very neck heavy.

Perhaps worst of all, I'd have to abandon the feature you see on the back of the T-beam versions: A flange of metal sandwiched between wood. I had (or have... I haven't yet given up on finding a T-beam) great expectations for the looks of this particular detail, which would resemble old sports cars' steering wheels well as some knife handles with the blade going through it.

The principle of making a full-aluminium neck that extends down to the bridge is not at all original. The guitar would more or less be a headless version of instruments like Electrical Guitar Company's Custom Guiar - which in turn seems to be based on earlier Travis Bean models, though it seems that the former has a wider piece of aluminium for the body, ensuring greater strength as the pickup holes do not completely intersect the aluminium piece.

The lack of originality takes some of the fun out of the project, but still, with headless neck and an ergonomic and very thin body, it still distinguishes itself enough from existing guitars to allow me to feel just a little like a pioneer.

Next week I plan to visit yet another scrap metal dealer. There might be a T-beam waiting for me there.

Monday, 2 July 2007

On the cover of the Rolling Stone

Well, almost.

There is a very fine article about the T-beam guitar on Building the Ergonomic Guitar. Have a look - and be sure to check out the other articles as well. There is loads of interesting information on guitars and ergonomics.