KTS Titanium or Carbon Fiber?

[medic82]

Love my "pointies," and trying to design a somewhat bastardization between a Jackson KV2 and B.C. Rich Kerry King Signature V. I am also drawn toward slim neck profiles, such as the Ibanez Wizard neck (17mm @ 1st fret - 20mm @ 12th fret) and the Jackson "speed neck." Conversely, I am NOT a fan of guitar necks reminiscent of a roller coaster at Six Flags...

The neck will be constructed of a maple-walnut-maple lamination (roughly 6/4 - 1/4 - 6/4), and the grain orientation of the laminates after glue-up will look like

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In addition to these precautions, I thought it would be wise to add additional strength to the neck with the use of supporting or stiffening rods. It seems that there are two prominent types of these supports:

1) KTS Titanium Neck Support Rods

These have been frequently used by Ibanez over the last couple of years, especially to strengthen and support their VERY thin "Wizard" necks. As a side note, according to claims made by both Ibanez and KTS, the properties of titanium will markedly improve the resonance and tone of the instrument (although I have not seen any empirical studies supporting this claim. IMHO, subtle changes noticed in the tonality and resonance would qualify more as SUBJECTIVE observations, rather than OBJECTIVE).

2) Carbon Fiber Stiffening Rods

I first saw these available from StewMac, but I have since seen them offered by a number of other luthiery suppliers, such as LMII (IIRC). Carbon fiber is well known for its significant strength and stiffness, while remaining very light-weight. While I cannot remember for sure at the moment, I believe the use of carbon fiber neck stiffening rods have also been attributed with changes to the tonal qualities of an instrument.

As I would like to construct a thin, wide neck similar to an Ibanez Wizard neck, stiffness and strength are important characteristics. Also, the scarf joint of the headstock should meet the neck roughly at the 3rd fret. I have heard from several people that scarf joints AND slim-profile guitar necks are substantially more prone to breakage and/or serious damage. My thoughts are that using the titanium rods would greatly reduce the likelihood that the neck would break at the scarf joint (although, the carbon fiber may accomplish the task equally well). As for pricing, I have seen the KTS Titanium rods on eBay for $20/ea. While I do not remember an exact amount for the carbon fiber stiffening rods offered by StewMac, I think the are similar in price.

In closing, I am very interested in hearing from anyone with insight into either, or both, method for supporting and stiffening thin guitar necks. Are there any differences noticed in the effectiveness at restricting or reducing any neck flexing, twisting, or breakage.

[curtisa]

I'm about to try and build a neck with carbon fibre reinforcement myself, so I'm also keen to hear what others' experiences are.

My gut feel is that reinforcement by itself probably doesn't offer much in the way of support to specific areas of the neck (eg, scarf transistion), but rather supports the neck as a whole and minimises the tendency for thin or weak necks to twist or bow excessively, or gradually shift over time due to seasonal changes. I imagine with enough of a blow you could still split a scarf joint with a neck fitted with reinforcement. The head may not shear off as easily, but the glue line would probably still fracture.

I think you can probably get better value from a dedicated supplier of carbon fibre rather than forking out a premium from Stewmac. I just bought 6x 1 metre rods from a CF stockist at $10AU per length. Each rod can then be cut in half and will do one neck, one rod either side of the trussrod. Much better value than the $17US Stewmac charges for one 18" piece. As expected it's pretty rigid stuff for its weight.

Can't comment on titanium, but I do wonder what exactly it offers over CF? Is it perhaps just the marketing flavour of the month?

[fairyforest]

Hey guys.

I'm quite new in the world of guitar constructions, but I spend long time modifying my guitar on my own.

What I try to say is I can't really tell you anything directly about the rods you're talking about.

BUT I spend many years with windsurfing, surfing and diving.

In these sports both titanium and carbon fiber are absolutely essential for high quality products.

Titanium is light and extremely strong, stiff and expensive.

Titanium blades stay way longer sharp than steel blades for example.

Carbon fiber is the magic invention after the glass fiber.

Extremely light and stiff. Very good flexibility. High end windsurfing masts are made out of 100% carbon fiber.

They allow the sail to twist, but it flexes really fast into its needed position.

I started to imagine my first guitar project from scratch and thought exactly about what you guys talking about:

Stiffness and reinforcement.

When you look at a classic surfboard, there is running a wooden bar through the whole center line called stringer.

In more complex windsurfing boards these stringers are modified to dense foam coated with carbon fiber and/or keflar fiber.

Also the mast tracks have special fiber reinforcements.

My idea was now to split up the whole neck or even the whole guitar to run a hardwood/laminated wood stringer through it with a layer of carbon fiber on each side.

It would guarantee and enormous strength and stiffness which would lead to a higher sustain and less twisting problems.

Now entering into detail about your questions:

You have a long cavity running along the whole neck, why not trying to coat it from the inside with a layer of carbon fiber?

If you would apply it properly with as less resin as possible and no air beneath you would get an supporting tube running invisibly along the whole neck

and protecting also your sensitive first frets.

I just read the first post again, you already planned to glue the neck out of several parts,

you could even make a combination of one of the mentioned thrust rods, a stringer and an inner carbon coating.

If the stringer also runs all along the headstock it should be nearly unbreakable and extremely stiff and twist resistant.

I hope you guys understood my ideas, like I said in the beginning I don't have your guys specific knowledge but I love creating and combining and transferring techniques.

Sorry for entering in more details again:

I just checked your mentioned thrust rods, I would prefer the carbon version.

If I understand it correctly they are mainly intentioned to run beside a main rod, because you cant adjust them at all.

In the instructions it says that the titanium version needs no resin, which is correct,that would not make any sense at all because it won't stick to the metal surface.

But if you sand the carbon rod and than apply the resin it gets one single piece with the surrounding wood!

It still offers a slight flexibility, is lighter and really, really stiff and strong...

I guess I'll stop now, I guess you got it.

I'm looking forward to discuss about this topic, I would really like to see guitars with up to date technologies and materials.

I don't really understand that the guitar industry sticks so much to designs and methods invented 50/60? years ago.

In it's moment it was really cool, but hey guys, we're in the 21 century.

That doesn't mean at all that I don't like oldschool constructions,

but I would like to see more evolution and mixtures of both worlds.

Enjoy,

Michael

[Prostheta]

I've never been convinced by Titanium inserts. It might be the huge amount of marketing wash associated with it. Carbon fibre is definitely a useful addition, however consider a different section to rod. I-beam (this sans serif font doesn't show that it's more like an "H" in cross-section) carbon fibre is stiffer than the equivalent rod. Again - as curtisa mentions - check for specialist CF stockists. Google your local RC aircraft hobby stores. They love their light-strong section composites.

As for the "sound" or "resonance", yes. Totally subjective. I personally think that necks which are composites of several different materials (including different woods) perform better than those made of one or two. Point in case being Fender all-Maple necks with their dead and wolf notes. Somewhat predictable in position also. Adding graphite/CF/Titanium/wood laminates to the neck alters the overall recipe.

Stiffening can be overdone. A neck is meant to be adjustable and manageable. One that is overly stiff and does not have any upbow whatsoever is unsatisfactory geometry. An ideal neck's stiffness should give marginally under string pressure. Just enough to provide clearance for the maximum deflection of the string in motion without buzzing. A truss rod should only need to do minimal adjustment either way, rather than being relied on for doing all the heavy lifting. A thin Ibanez-style neck benefits more from laminating with stiffer woods before relying on adding more complicated mitigation.

[fairyforest]

Hi Prostheta.

Interesting words you wrote there.

I was actually thinking of a construction which would result in a total stiffness and than shape the fretboard/frets into the needed position.

If there is no further movement, for what do you need to adjust it?

I wanted to get even furhter and take the adjustable rod completely out of the neck.

But sounds like a bit of fine tuning is the better solution.

I was always wondering why the trust rods ending half way to the bridge, now thinking about it,

it's quite logically: you just want a slight upbow on the upper frets (in Windsurfing masts you call it "flex top" in contrast to "constant curve").

Till which fret should it reach in the perfect case?

Taking into account that the maximum oscillation is at the 12th fret, I guess it should be around there...

...but we also have a slight downward angle since the bridge is higher than the nut, right?

I think t'is really fundamental because from the 12th fret on the whole system could be than as stiff as possible to get max sustain.

Actually there could be even a reinforcement between the first (maybe second?) fret going up to the headstock since this is kind of the weakest point because of the reduced thickness, is this correct?

I hope I'm not getting too theoretically, really love to abstract things.

For me it is really important to get a deeper insight of the essential functionality.

When I look at a bolt on neck I see always such an imperfect construction.

The neck should be an extension of the body, not a fiscally separated part from my point of view.

I'll go on fine tuning in my head, for now my AutoCad skills are not reaching so far.

Got at least my own fretboard designed..bit by bit, there is no hurry at all.

I don't know how to express that correctly in a decent english:

The path/way is the goal¿?

Passion and pacience,

Michael

[curtisa]

I suspect trying to build a neck that has the correct relief with no need for adjustability has several drawbacks:

• Any relief you build into the neck on purpose will only be suitable for a narrow number of scenarios - string guage, tuning, playing style, personal preference. As soon as you change one of those factors the neck will likley need adjusting to provide the ideal playability for the application.
• Building a neck with a specific pre-curve would be extremely tricky without access to very precise measuring and cutting tools, and/or custom moulds and templates, putting it a long way out of reach from nearly all DIY builders.
• Any imperfections in the manufacturing process or in the materials used would change the amount of curve the neck exhibits under string tension, making designing the initial amount of pre-curve unpredictable.

I was always wondering why the trust rods ending half way to the bridge, now thinking about it,

it's quite logically: you just want a slight upbow on the upper frets (in Windsurfing masts you call it "flex top" in contrast to "constant curve").

Till which fret should it reach in the perfect case?

Taking into account that the maximum oscillation is at the 12th fret, I guess it should be around there...

...but we also have a slight downward angle since the bridge is higher than the nut, right?

Maximum string displacement at the 12th fret is only true if the string is plucked while not fretted. If you play the string at the 7th fret the maximum displacement is midway between the 7th fret and the bridge - somewhere around the 19th fret.

The "shape" of the neck relief is probably more important than the amount. A gentle curve along the length of the unsupported section of the neck is required to allow the vibrating string to clear the frets, rather than a straight line. The curve shape approximates the shape of the string once it vibrates. Usually the curve is initially caused by the string tension itself and then partially nulled-out and fine tuned by the trussrod.

In most cases the trussrod ends before it reaches the body because the neck/body join makes the neck stiff enough to not require extra reinforcement, and so any flexing under string tension will not require adjusting against. In some situations you will find that the fretboard/frets have been levelled with a gradual fall-off after the neck/body join to allow a bit more clearance under the highest frets where adjusting the trussrod has no effect, to prevent fret buzz in the higher regisisters.

I've always imagined extra neck reinforcement to be used to provide resilience against unwanted movement after the trussrod has been set. The neck should be stiff enough to hold its shape after being flexed against string tension, but not so stiff that it cannot be moved at all by the trussrod if required.

[SwedishLuthier]

Lika mad man I keep pushing the notion that we usually doesn't utilise the graphite/carbon fibre reinforcement in the best way. If I had time I would re-do this 10 year old experiment with real carbon fibre:

http://projectguitar...h...st&p=216422

[fairyforest]

Impressing...

... need more time to go through all that and I'll post further ideas and I also want to give it a try.