MEANGENE
GENE BAKER
So You Want to Build a Guitar? Pt. 2
Welcome back to our neck thru guitar proj- Fretboard Thickness
ect. Last month, we discussed using CAD This is an important note pertaining to
to design, and now we’re ready to start the fretboard and/or neck to body plane
measuring. Our specs are roughly as fol- offset. For this project I want to keep with
lows: a Wilkinson VS300 tremolo, Sperzel a fretboard edge thickness of .170” to .180”,
locking tuners, 5-way switch, Volume, Tone, so when I draw my fretboard I’ll take this
Tone with push/pull coil-split, top-loaded into consideration as I generate my width
controls and pups, arranged HSH using and fretboard radius, ending up with a final
DiMarzio Virtual Vintage Series pickups. board thickness between .230” and .250”
The neck is a 25. 5”
scale, has 22 frets, 12”
radius, 1.680” nut and a
2.250” heel width and
features a 12 degree
angled headstock,
drilled 3x3 with straight
string pull.
basic truss rod used by most major
manufacturers. In the bottom shape of
the channel, the key is to get the rod to
react its best against string tension. It can
be a consistent arc, which is where most
people start, or you can tailor your own
ideas. Other two-way rods often get a flat
bottom channel, making routing them with
a plunge router very easy. An arc channel
requires you to create a jig
that has raised arc-shaped
rails for the router base to
ride on, to give you the final
depths needed for your truss
rod. Our truss rod is a 7/32”
diameter rod, so I’ll use a
7/32” ball nose router bit to
cut a matching round bottom,
no plastic sleeve required. I
highly recommend lubing up
that truss rod with some raw
beeswax to keep it operating
smoothly for life and help
avoid any glue that may
come in contact with it.
The Tremolo
The block on a VS300
requires a body thickness of 1.750” to 1.780”,
but you may find ways
to manipulate that
depending on if you
use a tremolo or hardtail bridge. This bridge
requires a target string
height of 12/32” to
13/32” from the body
surface plane to the
string height plane. You
can learn a lot from
guitars already built
and playing fine. If you Calculating the neck thickness
have a guitar that is a good sample for at the thickest points. On some necks the
the bridge you wish to use, just reverse fretboard thickness at the edge grows
engineer the process. Set up the guitar to thick to thin, based on how you cut the
proper playing specs (bridge height and radius in relation to the neck plane. I like
truss rod), lay the guitar on its back and it consistent, plus the side dots are easier
remove the strings. Place a straight edge to center that way. You can play with the
or good yard stick along the center of the final fretboard thickness – some like ‘em
fretboard. Also view the current truss rod fat, some thin – but the truss rod can also
setting – it should be flat for this refer- demand certain neck shape thicknesses,
ence. Using a 6” machinist rule, measure based on truss rod depths at critical points.
the distance between the top of the
body (our body plane) and the bottom of
the ruler (our string plane) viewed at the
intonation point – in our case, 25. 5 inches
from the nut.
Next month we will make a
check list of all the opera-
tions, cutters and drill bits
to be used and story book
the entire process for refer-
ence and editing as we build
any model. If you can see
your project from start to
end, you’ll have a far greater
understanding of all that is required and
work your way around obstacles. Stop
back next month as we start wood
chucking and gluing.
Truss Rod
For this project I am using what I refer
to as a “compression” truss rod, which
requires an arc cut channel; it’s the same
Gene Baker
Any questions or comments visit
www.finetunedinstruments.com www.meangene.org
email me at b3gene@verizon.net
Fine Tuned Instruments LLC, home of his “b3” instruments.
