Saturday, 30 June 2007

Bridge and tuners for the headless design

Having settled on a headless design, one of the next questions was which bridge and tuners to use. A small number of bridges with built-in tuners already exist, e.g. the ABM or the Steinberger. Unfortunately, they are all fairly expensive, and it was a fun challenge to try to find a cheaper (and perhaps better) alternative.

One of the first ideas was to mount traditional tuners at the bottom as shown in my previous post "The Ergonomic Guitar". To make room for them all - plus the fingers when tuning - the bottom end of the guitar would have to be cut at a quite steep angle. That actually looks quite good and fits well with the idea, that the body should support the right arm (assuming you're right-handed). The T-beam can extend into the upper wing in an elegant way.

Unfortunately, the angle of the end of the T-beam had to be *very* steep to allow for room for all the tuners. An alternative would be to use string trees to guide the strings to each tuner - the strings would then spread out from behind the bridge as they do at e.g. the Kramer Duke (which happens also to be an aluminium guitar with the neck going all the way through).

To get a cleaner look and ensure sufficient downwards pressure on the saddles, one could improve this design by letting the strings dive down behind the saddles and continue on the backside of the guitar on to the tuners. To avoid to much friction when tuning, it would probably be necessary to use a very slippery material for saddles and for the material on the bottom, on which the strings rest.



On the picture, you can see that I chose to let the saddles rest directly on top of the T-beam instead of on a bridge plate. I assume it will improve sustain.

On Building the Ergonomic Guitar, a couple of headless guitars using Steinberger Gearless tuners have been described. Todd Keehn and Scott French have used them. Unfortunately, they both mount the tuners the way they're intended, meaning that the strings run on top of the guitars and into the tuners. That means that you'd have to reach to the back of the guitar and feel your way to the tuner in question. It works fine on a traditional guitar where the tuners are mounted on the guitar's head, but for a headless guitar, I believe it is not very practical.

If the Steinberger gearless tuners were mounted upside-down and the strings were routed below the surface of the T-beam (as in the earlier described idea with traditional tuners), the knobs would be on top of the guitar where you could see them. That would make for a clean design and improved usability.




The picture above shows the guitar (without the wings) using this configuraion. Furthermore, the separate saddles are replaced by a custom cut one-piece bridge made from TremNut or a similar low-friction material. That means that the bridge has a fixed intonation like the Les Paul Junior bridge and those on some PRS guitars. I like the idea of these bridges: The less separate parts, the better sound.

Besides Building the Ergonomic Guitar, The Project Guitar site - and especially the forum - has been a great source of inspiration and information. On the forum, a number of alternatives to traditional headless bridge/tuner combinations have been proposed. Among these, there were two, which I found especially interesting.

One of the regular posters had made his own tuners with separate saddles for a bass. With a little modification, this principle lends itself very well to the aluminium T-profile: You can mill six grooves for the tuners and saddles in the top flange of the T-beam - as shown in the picture below.



The knobs are in two planes, as this allows for bigger knobs and therefore easier tuning than if they'd all been in-line. That would be a really nice way of taking care of tuning. Unfortunately, I have almost no experience in metalworking (cutting the T-beam into shape is in itself a daunting task), so this idea will have to wait for later.

Another of the regulars at Project Guitar had used the Schaller 456 fine-tuning bridge for a headless travel guitar. The fine-tuners can't go very far, but he uses a string-mounting procedure with a pair of pliers and a locking nut, ensuring a sufficiently precise tuning when tightening the string with the pliers. The fine-tuners do the rest of the job. I've settled for this solution for the prototype of the T-beam, as it involves relatively little and uncomplicated metalworking as compared to the other solutions.

A very rough sketch looks like this:



I've bought the bridge (as well as some other components), so now that's settled. At least for the prototype. I'm especially keen on trying the Steinberger Gearless/TremNut fixed-intonation bridge combo on a later version. But as this is my first guitar project, I want to reduce the number of things that can go wrong, and the Schaller fine-tuning bridge offers a proven combination of bridge and tuning.


26 comments:

Robert Irizarry said...

I love the shape of this latest iteration. In fact, the cutaway sweep of the bout was something that I was thinking about as well for a future project. I always wondered why neck access high on the neck wasn't a greater priority in the design. I somewhat compensated for this by going with a thinner body thus eliminating .25" from the thickness at the neck and body joint.

Alex said...

Hi Robert

Thanks. I also think, it looks good, though I also liked the angled cutoff in the earlier version... It blended in with the wooden extension for right arm support very nicely.

Luckily, the T-beam-guitar has no neck joint, so I won't have to overcome issues such as the thickness of neck and body joint.

Would your next version be like the Klein, just with a different sweep? Have you considered a neck-through for that build? That could allow for a very thin guitar. I myself have looked a lot at the necks at soulmateguitars.com.

Actually, I consider making the T-beam *really* thin - like some of the guitars at blackmachine.com. Still haven't decided exactly how thin yet.

G L Wilson said...

I thought the knobs were on the front on those Steinberger gearless tuners. You shouldn't have to fumble around the back at all. At least that's the way it appears in the pictures to my eyes.

Alex said...

I must admit that I've only seen pictures of those tuners, never held them in my hand.

But have a look at pictures such as e.g. these: http://www.stewmac.com/shop/Tuners/Guitar,_solid_peghead_tuners/1/Steinberger_Gearless_Tuners/Pictures.html#details

I believe that the knobs with the cut-off sides on the top of the headstocks must be for securing the strings (that's where the strings enter the tuners).
The round knob (on the back of the headstocks) must be for tuning.

Doesn't that make sense? Even more so, since when they're mounted on a headstock, it is easier to tune from the bottom of it than from the top.

Can anyone else shed some light on the subject?

Alex said...

Whoops! The link to the Steinberger earless tuners doesn't work. But I've added a link to the tuners in the post itself.

G L Wilson said...

OK, I think I see what you mean. But if they're locking, would it matter so much if you had to tune it round the back?

Have you seen the LSR Precision tuners? Their small size would mean that then could be mounted much closer together. Unfortunately, I see they've suspended activities for the time being. Nevertheless, it's another idea to throw into the mix.

Alex said...

You're right that the tuners being locking, it doesn't matter that much whether they're easily accessible. But aluminium expands and contracts with temperature, so I expect frequent tuning to be necessary. Plus - and perhaps most importantly - I'm the kind of guy who simply *has* to make a few adjustments every time I play ;-)

But yes, for the TK and the Scott French guitars, it probably is of less importance.

The LSR Precision tuners look interesting. Too bad they're unavailable at the moment. They could solve my problem with having the tuners too close together.

Anonymous said...

I Am also in the building of a headless guitar neck as well. i based the body off an old squire i bought off my friend. I am plannign to make the neck out of rolloed carbon fiber/kevlar weave. this gives the guitar neck an unnatural ability to stay straight, even cut very thin, as carbon fiber is almost 5 times stronger than steel. this eliminates the truss rod, as epoxy is non bendable, and that your guitar is really light. I planned to machine the rolled tube of carbon fiber into a half circle using a milling machine, the use a verticle sander to make it as thin as the hallowed ibenez wizard necks, but with a non symetric cut, IE one side of the neck is going to be thicker than the other, allowind it to be light, strong, sweet looking(kevlar comes in aldifferent colors) and easy to transition from cords to single note, and then having some thing to push agains when your playing heaver rock, metal, you name it.

Anonymous said...

with the tuners, i had planned to use a bridge off of a gibson, the tune omatic or whatever its called, and instead of the stop plate, i was going to make somthing very similar in size, but with the tuners at the end, very similar in apperance to the stienberg synapses, but instead of having the whole nob, i was going to replace that with knurled poles, with a 1/16 allen wrench hole, for tuning, since it will be tight to fit all the fenders tuning mechanizms in such a small tolerance area.

Anonymous said...

And with what alex said, dont use aluminium, it is a really soft metal and the smaller gage strings will slice through it like a garote wire. if u use case hardend aluminium, you might have a chance, i belive chromoly is nonmagnetic, so it wont interfere with the pick ups, as well as titanium, which in whole sale blocks ready for machining, isnt to expennsive. other non magnetic metals include:aluminum,brass,nickel,copper
,bronze,gold,silver
,platinum,lead,palladium,
zinc,

Ian said...

Also up the top at the end of the neck, how do you plan to fit the strings, i assume you are going to have the ball end of the strings come up through the neck and down into the tuner. i was in the middle of designing a plate with 6 slots cut into it, tig welded antoher plate on the sides so now its about 3-4mm wide, with 8 small machined borders seperating the strings. another plate tig welded on the top, grinded, sanded, machine a custom logo, and a foldable hinge witha magnetic stop for it on the large reciving plate, so overall, you have a flush plate, 3.5mm wide, 3.5cm tall, and 4cm wide, and a curved bottom to stay flush with the neck.
I used the TIG welder by the way because its a small heat zone, so you dont warp the plate, and then im sending it off to be crhromed, so it will look really nice!

Alexander Gorm Øst said...

Hi Ian

It sounds like a very interesting - almost revolutionary - build. I get the impression that you'll be using a factory made carbon tube cut in half (or close to half) lengthwise, but when you mention an asymmetric neck profile, it sounds like you're going to make it from scratch. Is this the case?

Regarding the stiffness and no need for truss rods, I've had second thoughts lately about using a straight aluminium bar. I believe that the neck is actually supposed to curve slightly, to give so-called relief to allow the strings to vibrate without buzzing on the frets or fingerboard. Since the amplitude of the vibration is largest at the middle of the vibrating string, this is where you want the greatest distance to frets or fingerboard. It might be possible to make built-in relief in a carbon fibre neck, which I think you should consider.

Using an allen key for tuning sounds like a good idea. The drawback is that you have to get hold of your key when you need to tune the instrument, which might be stressful if you're playing live. I haven't done any gigs for twenty years or so, so usually I'd be able to pause playing and find my toolbox. Btw, I really like when people use standard components such as nuts and bolts on their instruments. Some might find it cheap looking when you're not using dedicated guitar components, but if it does the job and looks good, it's just common sense.

Regarding the softness of aluminium: The two-string bass, which I am building now uses flatwound strings. Still, they make a significant wear on the T-beam, so I do have the problem of wear that you mention. But I think that some of the harder aluminium alloys are more wear resistant. Plus, if you have a fretted instrument, the wear on the fingerboard itself should be way less. Other metals might be useful as well, but one of the benefits of the T-beam guitar is that materials are cheap and available. Plus, aluminium sounds great and is a proven material for guitars and basses. Bronze (especially the "bell bronze" alloy) might sound good too, but I don't think you can buy a bronze T-beam. In addition, it's quite expensive (as is gold and silver, btw ;-)

Earlier on, I planned to use relatively traditional tuners and then having the ball ends of the strings on the headstock end. In my later designs, I reversed that and intented to have the ball end of the string in the tuner block and fixing the non-ball end with a screw, a locking nut or similar. But I think it is possible to make room for an allen bolt in the tuner block where the ball end rests (see e.g. the first picture in this post [http://tbeamguitar.blogspot.com/2009/01/new-tuners.html]), loop the string around the shaft of the bolt and then tightening it. That would allow you to thread the strings throuth holes in the headstock end of the guitar without needing complicated and heavy fixing mechanisms. At least if it's a guitar (which I intend to build later). Bass strings might be to thick to bend in such a small loop.

Your headpiece sounds interesting, but I'm afraid I don't quite get it. Do you have a picture or sketch? It sounds like you've thought it out well, but I have trouble visualising it.

Ian said...

Sorry, the only sketches i have are in very rough shape, as i just frew them one day when i got sick of looking at Synapses and ho to make them better. The carbon fiber precut rods you were taking about would work, but the plan was to buy a +100 foot roll of the carbon/kevlar weave in bulk, then on a lathe, mount a thin titanium rod Prelathed to a specific thickness, then some how attach (Tape?)the begining of the carbon roll to that pol, have a person from behind the lathe guard hold a buckeet of epoxy and while the lathe is spining(Slowely!! i dont want any one trying this at like 1800rpm "just to try it") generously put on the epoxy, it has to be thin enough to be poured, but thick enough not to run, like a cake batter consistensy, then the other person, while the lathe is spinning at the slowest possible speed (you might have to put a gear reduction box in, as i think the minimum for the lathe i have is like 400rpm, just a little too quick to pour on the epoxy!) 3-10 rpm would be ideal, the other person in front of the lathe is holding the roll of carbon fiber, on a dowel or something, and is putting tension on it. ur not trying to stall the lathe, but a fair amount of tension, so it raps tightly, and once this process is set in motion, u want to do the whole roll, and then once every thing is wound up tightly, wipe off excess epoxy and put a healthy dose of thick(lobster claw) rubber bands around it to keep it from "adjusting".

Ian said...

also when you said something about having the neck bend slightly, this can be remedied by simply adjusting the hight of the bridge and the end of the neck(however you have it set up) also i didnt really have enough time to really go indepth about how i was going to finish the neck, i was going to sand it into a slightly curved profile, Another alternative is using precut carbon fiber slabs, usually you can get a rather large sheet for aroung fifty bucks or so. what that means is that you can stack these like lego blocks, but you have to make sure that every on aligns. it would go together like this

_______________
---------------
-------------
----------
----
sorry for the crude methods above, but i didnt have a sketch on hand, but every one of these lines represents a sheet of carbon fiber about a mm wide. thes are extremely rough sheets, more used for structure and support rather than asthetics, but once you have these set in place well (remembering to do these two sheets at a time as these can shift if you put more than 3 of these at a time,) then rap it in your color, pattern and price choice to make it astheticly pleasing.

Alexander Gorm Øst said...

So you want to make a massive carbon/kevlar roll saturated in epoxy resin and mill it down to the desired neck dimensions? Do fibres and resin mill well? I would think that it would be a messy and hazardous undertaking and that the fibre ends would stick out, hurting your fretting hand. But of course, if coated in something it might work. But I was under the impression that generally, carbon, kevlar, fibreglass etc are more suitable for molding, followed by sanding raher than milling.

Another thing: If you have a massive carbon fibre neck, I believe it would be unnecessarily strong. Not to speak of heavy. Carbon in resin is light considering its strength, but doesn't it still have a high density compared to e.g. wood?

It sounds like an expensive process. And perhaps messy... I'm glad it's not my lathe (not that I actually have one). I am no expert at all in working whit fibres and resin, but it sounds like making an inner wooden neck core and covering it with e.g. 3 mm carbon/kevlar, thereby reaching the desired girth - would do the trick. But again, I don't know much about it.

Ian said...

I am wondering what kind of pickups ur going to be useing as well, their is a few on the market that would make the aluminium guitar look really nice, they are a mix of clear plasit and red wound wire, and i think it would fit really well with the wooden wings and silver of the aluminum,


Also, with the strings being attached, you could fallow steingberger and have double ball strings, and just use something akin to a whammy bar to loosen the bridge put the strings in and let the wammy bar back under its own spring pressure would tighten the strings. of coure you would have to find something like a locking mechanism to hold it from being just loosened. this would be a quick and efficiant means to change strings very quickly, but i dont think it would work very well, unless you have the determination to see it all the way through

Ian said...

It mills pretty well, it dulls bits really fast, but if you can afford the massive amount of carbon fiber then go to town. im thinking about people who abuse their guitars when i think about solid carbon fiber necks, think those people who smash their guitars! kidding, but when you mill carbon fiber, fiber glass or whatever fiber your milling, you have to wear a suite similar to the ones they use in the collision repair industry. the fibers are in the same family as asbestos, but not as cancer causeing. they cause irritation and blindness if they get in your eyes. It would be redicously strong, but my friend mad a solid carbon fiber baseball bat, besides being one of the lightest baseball bats ive ever felt, it was also able to sent the ball aver the homerun fence, with minimal recoil as it abrorbs a good amount of shock from the blow. the reason you make the neck solid is that vibrations lose their intensity through every material they go through, includeing the most resounding material.
another thing, i hope you dont think im trying to lathe it when its still wet, as carbon fiber has to cure for 2 days for every 10 layers you put on, so thats about 30 days of cureing!
If i had a suitable thin plastic tube to wrap it around, yes, that would save a lot of money, but as i dont know how that would affect tone or anything like that, do you? it wight actually increase the sound, as it might bounce around like a semi hollow guitar

Ian said...

sorry about the horrible spelling, im really tired, and yeh, the resins arent the problem. after your done with the wrapping process you sand it heavily, with really large grain sand paper, then thiner, and thinner until your up to about 350 grain, then coat it in a specialy design poly urathane designed for carbon fiber. you have to hunt this cover down, because if you want to see the wonder fol work youve done it has to be clear, but if you want it to last, you have to coat it in something clear and UV ray proof. As carbon is an organic element, it decays as sunlight or uv light hits it.

Ulf said...

Hi Alex

I really like the shape and contour of your headless design called "The ergonomic guitar". I am planning to build something like that. The project is based on Rolands midi microphone - so it will be some kind of synt ax. Is it ok with you?

Ulf

Best regards

Alexander Gorm Øst said...

Hi Ulf

Please use whatever principle or design I've come up with for your project. It's always fun to see other people's implementations of your own ideas.

Please drop me a line when things are progressing. Have a nice project :)

/Alex

Ulf said...

Thans Alex,

I´ll be back

Ulf

Ulf Mossberg said...

Hi Alex,

my guitar project of the ergonomic guitar is now finished. There is a small videoclip on fandalism. I hope you recognize the shape.

http://fandalism.com/uffemossberg#!/uffemossberg/bVZl

Alexander Gorm Øst said...

That's amazing. It's a beautiful guitar, and if that's the one you play in the background music, it sounds beautiful as well.

I am really thrilled to see some of my design manifested in a real instrument.

Ulf Mossberg said...

Thank´s Alex

Keep up the good work with your instruments and blog. I really think it´s a source to inspiration.

Mark Gregory said...

What is a good choice for adjustable rollers where the tuning pegs are behind the saddles ?
I want something heavy to improve sustain...

Alexander Gorm Øst said...

How about using the saddles of a Wilkinson roller bridge?

(this one: https://www.google.dk/search?q=guitar+wilkinson+roller+bridge&client=firefox-a&hs=Zj0&rls=org.mozilla:en-US:official&tbm=isch&tbo=u&source=univ&sa=X&ei=QKm1Uda6NcTf4QTt6YD4BQ&ved=0CJ8BELAE&biw=1370&bih=812)