TOONE & TOWNSEND tuning hardware fully controls string vibration and intonation. The integrated system anchors both ends of the string in precision components machined from anodized aircraft grade aluminum, bearing bronze, stainless steel, and titanium.
As photographed here, strings pass through the bridge to the body mounted tuner. This provides warm, woody, acoustic vibration, saturated with the tone wood characteristics of the body. Sustain is enhanced and solid, due to the mass of the tuner.
"Sketch is one of the most well built, well conceived instruments I've ever owned or played."
Interlocking tuning knobs feature neoprene O-rings provide non-slip grip, even under sweat inducing stage lights and performance conditions.
The nut provides fully adjustable intonation and string height control. Any string gauge, scale length, or string material (nylon, bronze, steel). Installation is simple.
Intonation can be dialed in by the musician for specific preferences, from piano-like clarity to traditional guitar dissonance. 7-string version pictured here anchors ball end strings.
This patent pending system is available for licensing. For more information about this 7-string guitar by luthier Rick Toone:
Final tests are underway for the production version of the patent pending TOONE & TOWNSEND intonation adjustable guitar nut.
Weight is 3 oz (equivalent to 2-3 conventional tuning keys). This becomes a very substantial neck weight savings as the headstock is eliminated and tuning is relocated to the body.
Compactly engineered to 3.25" (8.25 cm) length x 0.5" (12.7 mm) height. Very precisely machined from aircraft grade aluminum, this lightweight component performs three important functions:
• Anchors plain or ball-end strings (ball-end version shown)
• Allows a full 0.5" (12.7 mm) of intonation adjustment
• Allows simple string height adjustment
Compatible with all body mounted guitar tuners, including: Steinberger, ABM, Bondy, Strandberg, and TOONE & TOWNSEND. Including tremolos.
NOTE: Currently, the nut is availably only on instruments by luthier Rick Toone. Contact Rick with instrument inquiries. Public release date for the nut as a single component is pending.
Incredibly strong and lightweight, TOONE & TOWNSEND headless guitar tuners begin as a solid block of aircraft grade aluminum. CAD controlled CNC machines will sculpt each block to precise tolerances. Chips are collected and recycled. There is no waste.
If you are used to listening to the sound of your guitar's vibrations through inexpensive cast or stamped bridge hardware, the clarity and inherent musicality of machined hardware will really surprise you.
Everything matters. Each metal contributes to the final tonality of these pieces of machinist art.
Townsend machinist KC holds a partially milled 6-string guitar tuner beside an unformed aircraft aluminum blank. The result is a contoured 3-D mount like the CNC test calibration example below, still warm from machining (11.10.2010).
This article explains in detail how to build an instrument neck using the TOONE & TOWNSEND Neck Core which has been engineered from aircraft aluminum.
I've been using neck core lengths from about mid 2nd fret to the body joint. It does not need to extend the full neck length. You can cut and file it as needed.
The basic steps are very simple:
1. Work from a centerline
2. Route a groove using a 0.75" (19.05 mm) diameter bit
3. Square the ends of the groove with a chisel
4. Glue the neck core and fretboard at the same time
5. Shape the neck
I've built many necks using this method and learned through experimentation the neck core is the most important factor determining tone and stability, for reasons outlined in neck design theory. Note the Trapezoid Neck Profile was specifically designed to accommodate an oversized neck core.
MATERIALS
Steel (even stainless) is not suitable due to oxidation, and other metals such as bronze do not have sufficient strength-to-weight ratio. Aircraft grade aluminum and titanium have very high strength-to-weight ratios, with musical tonality. TOONE & TOWNSEND neck core is available in titanium, by request. Titanium pricing is substantially more than aluminum.
VIDEO: Starfish claro walnut six string electric guitar. Stacked laminate neck with aircraft grade aluminum neck core. This instrument was my first test of this neck construction method, and has proven exceptionally stable since 1993. TOONE & TOWNSEND neck core is a refined version of the truss structure used here.
CALCULATE FORCES
Guitar, bass, and emerging wide octave or extended range hybrids will be subject to variable string tension forces, depending upon scale length, string gauge and number of strings. Luthier Graham McDonald freely offers his Universal String Tension Calculator (MPUSTC) and it allows you to input your own variables.
NOTE: TOONE & TOWNSEND neck core is designed to reinforce acoustic and electric guitars, including baritone, most extended range hybrids and bass.
I prefer to experiment with actual materials combined with full scale drawings. Others may prefer CAD and Young's modulus engineering charts. The same design and construction principles apply even to CNC operations. If you have expertise in contemporary machining methods please consider sharing your knowledge with others here. I will present the construction techniques using hand tools, for those who do not have access to elaborate technology.
DETERMINE DIMENSIONS
Once you've approximated string tension forces, evaluate outside dimension requirements for the neck profile at the smallest cross section of neck (nut) including width and thickness including fretboard. I have found musician's preferences vary widely and are often associated with finger length.
Once you make an accurate scale drawing of the neck's smallest cross section, measure the thickness excluding fingerboard. Allow at least .125" of wood as a safety margin between neck core channel and outer surface of neck. Click image to enlarge.
NECK CONSTRUCTION
I always begin construction from an oversized square or rectangular block of (wood) material, regardless of the subsequent profile or shape of the completed neck. The reason for this is it provides one perfect (true) surface to route a channel into and attach a fingerboard onto. That true plane surface will serve as a necessary orientation guide throughout the neck shaping process.
It is important to work from a centerline — as well as from the neck material/fingerboard joint — in order to prevent accidentally cutting too much material away and exposing the neck core. When squaring the ends of the routed channel, remove only necessary wood. Route channel 1/64" deeper than neck core. This allows a slight gap permitting glue to move freely during clamping.
Be precise.
Neck core should fit perfectly, end-to-end, slipping into the routed channel without force or play. Finger press effort. We've allowed clearance for glue to move freely around the top, bottom and sides of neck core, as needed, to hold it in place. A precise end fit turns the inherent strengths of wood and metal to our advantage, without need to rely on a chemical bond. Note the aluminum neck core can be cut, filed or drilled as necessary.
Because the neck is subject to longitudinal compression, solid neck core ends distribute the compression load. Draw lines (or take notes) where the neck core ends to avoid exposure during neck profile shaping.
PHOTOS: Testing a prototype TOONE & TOWNSEND Neck Core. Curly quarter sawn red oak and hickory neck. Note neck centerline in router photo.
ASSEMBLY
It seems simple and intuitive, but this advice took me awhile to accumulate. With an open gluing time of less than ten minutes (warm weather) and a complex series of steps involved in assembling a neck, it will save you time and frustration if you follow these steps:
• clear your work space
• gather all materials and clamps
• do a dry test assembly without glue pre-setting clamp positions
• adjust any problem spots
• repeat dry test assembly
• clean aluminum neck core with denatured alcohol to remove oils
• glue + clamp neck core to seat fully in channel immediately remove clamps
• immediately glue + clamp fretboard
• allow 24 hours drying time before removing clamps
I've been on a quest for many years to find the perfect glue, a series of ongoing experiments.
Titebond II (aliphatic resin) has served me faithfully for about 15 years, as it is very stable throughout temperature changes and highly resistant to moisture, including sweat. It clamps nicely, sands smoothly when dry, and is quite strong.
Titebond III displays the same properties as Titebond II except I find the dried glue more "rubbery" during sanding, and the glue line more pronounced. For this reason I prefer Titebond II.
Hide glue is on my list to try, but I seldom need to disassemble what I've built.
Lately I've been exploring Gorilla Glue (polyurethane). Different from Gorilla Wood Glue, which I have not yet tested. Foaming action during bonding requires some getting used to but is not an obstacle to success. To avoid over-sensitization I use gloves, eye protection, ventilation and a respirator — the fumes affect my eyes.
I am very pleased with the strength and tightness of the joints. Glue lines are invisible.
During testing I submerged a cutoff walnut & maple scrap from the neck structure above. Even after 36 hours submersion and subsequent return to room humidity, the glue line was never apparent. Just as impressively, I could not break the joint. Immediately after removing the scrap from water, I bridged it (with the grain) and bounced on it using my full 185 lbs.
No damage.
PHOTO: Use a straight (true) clamping bar combined with as many hand tightened clamps as you can fit. Seek strong, even, pressure. Nadine Steinhard, marketing manager for Gorilla Glue, confirmed this method in a series of emails we exchanged about their polyurethane product.
PHOTO: Masking tape is invaluable for precisely positioning the fretboard on the centerline prior to clamping. Fingerboards are lightweight, thin, and really slippery when wet with glue. Tape them down firmly. I've found triangular wood strips effectively distribute clamping force on curved (or compound) radius fingerboards, particularly along the outer edges.
SHAPING
Cut the neck to desired taper, from width at nut to width at heel.
On the side of the neck mark the depth of the truss structure channel, confirm the neck thickness, then remove excess material to within .125" of desired finished dimension. Because the instruments I build invariably have a thicker body than neck, there is an exponential taper in neck thickness from nut to body, based on personal preference.
Most importantly, do not risk exposing the neck core unless you are seeking that deliberate effect. Transfer the centerline to the back of the neck and use it for continual reference.
Determine and mark the width of the neck core channel, measuring from the centerline. Those lines, combined with the taper of the neck width, determine the minimum possible dimensions of the profile. In fact, I use the glue joint of the fretboard to neck as my reference — I seldom cut into the fingerboard itself, once the neck width taper has been established, preferring to leave as much fingerboard material as possible.
PHOTO: Marking the intended neck thickness on the blank. Neck has already been tapered to width. Note luthier's headstock joint in the cherry. Curly maple fretboard.
PHOTO: Trapeziod Neck Profile is clearly visible in this construction shot of Dove six string electric guitar. Note unusual asymmetrical slotted headstock.
SETUP & ACTION
Leveling and contouring the fingerboard pre-fret installation is critical to controlling action outcomes. Once the neck has settled in for several days and the glue fully cured, evaluate the fingerboard using a precise straight edge. Now is the time to make adjustments.
Typically a perfectly straight fingerboard is desirable. String tension will pull relief into the neck. On "soft" necks, you may choose to build in a back bow. With experience you can predict the amount of neck relief based on the materials chosen. It is not an easily quantified formula because so many variables are involved, including fret compression. Always string and test instruments EARLY in the construction process, before sanding and finishing.
I've successfully used the methods described above since 1993. The instruments I've built using "conventional" adjustable truss rods are not nearly as mechanically stable nor sound as good, in comparison. What I've explained in this article is exactly how I would build an instrument for my personal use.
Please extend this discussion by sharing your experiences in the comments below.
Orchid bass has been described as having "piano-like" sound. Each note within a chord rings with distinctive clarity. These differences are clearly audible as Monster plays (1:58 to 6:32) in the video below.
Characteristics consistently apply to other instruments I've constructed using our Toone & Townsend Neck Core so it is not a function of Orchid, but instead of the neck design itself.
Neck core installation methods I've been using are designed to facilitate string vibration transfer by minimizing twisting and bending of the neck. Our Toone & Townsend half round ("D" cross section) neck core maximizes gluing surface and fretboard contact, yet allows conventional or slim neck profiles.
PHYSICS OF VIBRATION
In theory, a perfect neck would have zero flex, instead transferring all string vibration directly to the soundboard.
The reason for this is found in Newton's law of reciprocal actions: "For a force there is always an equal and opposite reaction: or the forces of two bodies on each other are always equal and are directed in opposite directions."
A string in motion creates force, in the form of vibration.
According to Newton, the neck and body of the instrument will react equal and opposite to the force of the string. This is important — and good — because it is the movement of the bridge against the body that amplifies string vibration, creating audible sound.
When I write "body" what I specifically mean is soundboard, because the body of an instrument serves two functions: a) an ergonomic device for musician comfort, and b) to amplify string vibration.
We often think of soundboards only in relation to acoustic instruments, but even a solid body acts as a soundboard. The same physics are involved in a solid body, archtop or acoustic guitar, for example, but each design has been optimized to amplify acoustic sound to varying degrees.
Kettering University's modal analysis of an Ephiphone Coronet solid body electric guitar clearly illustrates the movement of the neck and body in (equal and opposite) reaction to string vibration. Each animation is a different frequency, so an accurate model would combine all of these frequencies plus those not analyzed.
MAXIMIZING STRING VIBRATION TRANSFER
Because the neck does not act as a soundboard, the longitudinal and torsional neck flex apparent in the Kettering animation indicates lost efficiency. As the neck reacts equal and opposite to string vibration forces — by twisting and bending — it is not transferring string energy to the soundboard for amplification.
Additionally, these neck movements are acting to dampen string vibrations, as explained by Newton's law of inertia: "An object at rest remains at rest and an object in motion will remain in motion unless acted on by an unbalanced force."
Those of us fascinated by instrument physics can continue to learn from Isaac Newton — even three hundred years later — by applying his principles to contemporary design.
Toone & Townsend
Precision tuning systems for acoustic & electric stringed instruments. Designed and machined in USA.
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