Using traditional tuners for headless designs

A post on this blog contains some nice sketches of headless guitars with traditional tuners mounted behind the bridge. Some designs even had holes through the body for the tuners. That looked good, but it might be difficult to get a good hold of the tuners unless the holes are very big. Since tuner systems for headless guitars are few and expensive, using the old-fashioned ones in new ways is a viable alternative.

It struck me that a possible solution could be to mount the tuners on a metal plate in a hole routed through the guitar, the tuner knobs sticking up through the plate and the strings going through slots in the plate. I've fiddled around with designs like that before (only on paper so far), but in this particular case, with a tune-o-matic bridge, it seems especially straightforward.

On one of the sketches on the blog, it would look like this. Sorry about the artistic quality, the picture only serves to explain the idea.

I couldn't attach images to my reply on that post, so instead i put it here. Anyway, it shouldn't all be about T-beam guitars.

A magnetic pickup

Previously, I've talked much about piezo pickups. I had great expectations to piezo discs, because they would give me more freedom in construction, since I would avoid having to make room for traditional magnetic pickups. I still have expectations, but so far, I've not been successful in making or buying a suitable pre-amplifier. I've tried a couple of designs, but none have sounded very good so far.


For the sake of my own motivation, I took a little detour from the piezos and put a guitar humbucker on top of the strings. The distance between the two rows of pole pieces is 18 mm - exactly the distance of my strings. This makes it possible to mount it lengthwise over the strings. It gives acceptable sound, but the mounting bracket doesn't integrate well with the overall design idea of having a sleek stick for a bass.

On the other hand, it _does_ have a certain rustic honesty about it. And most important: now I can play the bass and get a decent tone, while I figure out if the neck should be a little thinner, rounder or narrower. As well as many other things.

Wooden sides

I made two wooden sides from some spruce, just to test how it worked. Also to avoid messing up my good mahogany plank with early mistakes. I routed the cavities for saddles, nuts, strings and tuners with an ordinary plunge router in a table. I have little experience routing, but the cavities do what they're supposed to.

I've tried to make the sides fit tight against the top flange by having the holes in the vertical flange just a tad higher than those in the wood. This way, when I screw it together, the screw tightens the wood sides towards one another as well as lifting them against the top flange. It works ok... if you see gaps, it's because the wooden sides are made quick'n'dirtily, not because there's something wrong with the principle itself ;-)

I'll be sticking with the spruce sides for a while. There's a lot of things that I am yet going to try out - and which will need holes drilled in the wood. The mahogany sides will have to wait until I've settled on a final design. This especially includes whether to make the neck thinner. It feels a bit too thick even for my big hands, so I might slim it down from 4 to 3,5 cm (that's from 1.6 to 1.4 inches). That will still be much thicker than a traditional bass neck.

New tuners

I've always wanted to try out my a particular form of tuners for headless guitars and basses. They work by having a scew pulling a brass block in which the ball end of the string is mounted. The main inspiration was Jeff Turpin's tuners; drawings and building guide for similar tuners can be seen at ScottyD's home made tuners. But since I have a T-beam, I can do away with the housings for the brass blocks that these designs use, and rather let them slide on the underside of the T-beam like this:

Two of the screws are for holding the brass plate on to the T-beam
The other two are for tuning.


I thought that 'd give it a try since I was going to cut the T-beam to length and I needed a bit of room for the tuners, so it was the last opportunity to try it out. It works very well - very smooth and precise, so I'll stick with them rather than reverting to the traditional tuners. I believe they'll be even better when I've mounted hex socket screws so I won't have to use a screwdriver to tune them. The holes where the strings go through the top flange could use some lengthening as well, which would make the strings' movement easier.


The picture shows the sharp turn, which the cable has to do going through the flange.

I'll stick with the new tuners rather than the standard bass tuners it had on earlier. That will also make it easier to make some good looking wood sides for the T-beam since I won't have to worry about making room for tuners that stick out. The brass blocks and string ends will be hidden within the body.

Earlier, while the traditional tuners were still on the bass, I was making and mounting a string tree that I needed for them. Unfortunately, the aluminium is so soft and sticky, that I broke off one of my threading taps inside the T-beam. Trying to get it out by cutting room around it with a dremel only made things worse. I'm afraid that I'll have to stray from my "form follows function" principle and make some sort of ornament to cover the damage, now that I don't need the string tree any longer.

Headstock-end with damage from string tree mounting attempt
(I later turned the T-beam around so this end was the bridge end back then).

On the image above, btw, you can see the strings going through the flange. They are secured on the underside by cable stops - the type used e.g. for brakes on mopeds.

Next step will be making the wooden sides plus some experimentation with Piezo pickup pre-amplifiers. And then back to tidy up the T-beam. Later, I am thinking about making a detachable body from steam bent plywood.

Stick Bass Pictures

I've made the spine of the two-string, nylon string, fretless piezo alu T-beam stick bass. Now I have to stick some wood and some piezo pickups on it.

Some photos:

I will shorten bot ends of the T-beam down to the tuners and string holes. Btw, these are not nylon strings as originally described, but flatwound steel strings. I found out that the pull of nylon strings wasn't that much lighter than that of steel strings, so I went for these instead.

I've played it with a cheap non-preamplified piezo pickup on the flange. Sounded very good and feels very alive... I'll make some sound samples to go here. It even sounds good bowed. Plus it was easy to bow; since it only has two strings, they are easy to hit even though the fingerboard is flat (as in not being "radiused" like the fingerboard of e.g. a violin). So far, I am really, really satisfied with it.


Common bass tuners mounted in oak blocks. Bronze saddles through top flange. And yes, the saddles aren't completely perpendicular to the top flange. I'll mount them in slots in the top flange rather than in threaded holes, which will make it possible to adjust intonation. And then I won't have to worry about my crooked thread-cutting.

Action is ridiculously high at the moment, but if I set it lower, the strings don't press properly down on the saddles. I need a string tree, but I'll make it myself, since the strings are 18 mm apart.

Making the wood sides is next. Plus, I might trim down the "fretting" part of the neck to 25 mm (1") thickness. It feels too thick as it is now (4o mm). I was going to do that at some point anyway, but now I'll do it sooner rather than later.

The local staircase manufacturer kindly donated a nice piece of mahogany, and I've just bought a table-mounted circular saw. Plus, I am eager to use my router that I bought over a year ago and haven't used much. Making the wood sides should be a breeze.

Hope springs eternal.

Setting my sights a little lower

It can't have escaped anyone's attention that I haven't yet built the T-beam guitar. Even though I've talked a lot about it, nothing tangible has emerged. I've bought the components and there's nothing much missing. It's just a question of doing it.

So why haven't I made it yet?

It's mostly due to my busy life with a job and two small children. Yet other busy parents manage to build guitars, so there must be another reason. I've been thinking a lot about it and have reached the trivial conclusion that the T-beam guitar is too big a task for my limited experience. There are too many things that can go wrong in the process, and that's keeping me back.

I've decided that I need an easier task to gain some experience. A task that gives me a reasonable chance of success. This means that I'll have to lower my ambitions and - for starters - build something much simpler: A two-string, nylon string, fretless piezo alu T-beam stick bass. This is way easier than my original goal (a guitar with frets, tapered neck, pickup cavities, etc.), meaning that I might actually get it built.


The instrument minus acrylic body

The simplicity (and hence increased probability of it becoming a reality) of this new project in comparison with my original idea is due to the following factors:

Fretless because:

• Fret, bridge and nut placement becomes less crucial or non-existing
• I don't have to think about adjustability for intonation (lengthwise adjustable saddles)

Two strings because:

• It is simpler than four strings.Whether or not to radius the fingerboard is not an issue.
• Stig Pedersen of D:A:D plays a two string bass ;-)
• I will be using the same basic design as e.g. Krappy Guitars and Longbow. This means that the neck won't have to taper towards the nut, which in turn means that I can use a standard T-beam and only cut it to get the desired length.
• The few times, I've played a bass, I've mostly used the two low strings.

Nylon strings because:

• I like playing nylon strings
• They put little tension on the neck, meaning that I don't have to install a truss rod.

A bass because

• I want to build something simple, and a two string guitar doesn't appeal to me.
• I don't want a fretless guitar. At least at present, I want my guitars to have frets and six strings.
• I don't have a bass, and I could use one. There's a good chance I might actually play it.
• I believe the human ear to be less sensitive to tonal precision in the low register. Therefore, fretlees is a more nearby option for basses than for guitars. On a guitar, it would be very, very obvious if a tone was even slightly off, whereas on a bass, your ears would be more error-tolerant. On a bass, there is a larger margin. And I can use that ;-)

Piezo pickups because

• It will serve as a testbed for my preamp/buffer experiments (thought I might swap some components when using them for guitars rather than basses)
• I want to be able to use nylon strings, and a magnetic pickup won't pick them up (unless they have steel cores, which would increase neck tension)
• I can use a much narrower T-beam than if I'd have to make room for traditional pickups and still avoid the top flange of the T-beam being completely intersected by the pickup cavity. Narrower means being able to use a standard 60 mm aluminium T-beam.

Alu T-beam because

• It gives me practice in building T-beam guitars, which is what I set out to do in the first place.
• It gives me the opportunity to experiment with mounting the piezos in different wood species on the quarter circle neck "sticks" (e.g. maple and mahogany).
• Using semi-hollow wooden "sticks", it allows for wiring and piezo placement in an enclosed space everywhere on the bass (headstock included)
• It gives me a reasonably hard fingerboard surface (depending on the alloy and temper), which is important with fretless instruments.
• The considerable thermal expansion and contraction of aluminium doesn't ruin intonation when the bass is fretless. On a fretted instrument, this is a problem. This makes aluminium a more suitable building material for fretless than for fretted instruments.

A stick (with detachable body) because:

• I believe that the body dampens the strings and reduces sustain. It's not so much the guitar body itself, but the fact that it rests on the player's torso and the player's arm rests on it. If you isolate the body from the neck (or "stick"), it will be able to vibrate more freely and without damping.
• It also allows a lot of freedom in designing bodies with ergonomics or looks in mind. The stick remains, but you can swap body according to your playing style and physique. Or your mood, for that matter. Plus, you can experiment with many different shapes and materials for the body. You can have a guitar body designed for seated playing and one for standing up. One for resting the guitar on your left thigh, and one for resting it on your right, depending on preferences.

That's a lot of reasons to build the thing. Some are better than others, but overall I believe the project to have a good chance of success.

A locking nut that didn't work

Since I put the T-beam guitar on hold for a while, I bough a cheap Gibson SG copy for various experiments. One of the first things I wanted to try out was a tuning system, which uses a locking nut in combination with a Schaller 456 fine tuning bridge

I need to be able to rough tune and lock down each string separately, so the usual ones with two strings per screw won't do. According to the idea, after rough tuning, the fine tuners in the bridge take care of further adjustments.

For some time, I've been looking for a suitable locking nut. After a while without identifying anything useful off-the-shelves, I decided to make one myself.


I started with a piece of 7075 T6 aluminium. I drilled six holes for the string locking screws and two for screwing the locking nut on the headstock. I then threaded the holes (M4).


I then made six grooves; one for each string.


...and filed the grooves smooth.


I mounted it on a piece of brass on the headstock, but the D string snapped when I tightened the screw. On closer inspection, the screws turned out to have very sharp edges, which explains why the string was cut. I'll have to file the ends of the screws flat. I'll have to shorten them a bit anyway, so that's no big deal.


Unfortunately, there was another problem as well: The pressure of the screws lifted the nut off the brass plate (the picture shows the gap between the aluminium nut and brass plate). That can probably be solved by making the nut a bit deeper and having two mounting screws on each side of the string locking screws rather than only having one set of screws.

I'm going to give it another try some day and make an improved version.

Btw, if it had worked, I would have bought six proper set screws for it and cut off the remaining headstock. In an artistic fashion, of course ;-)