So You Want to Build a Guitar? Pt. 6
This month, we continue with day three of The nut width is 1.687” and the butt width
our build and go face up, to do some rout- is 2.250”. Finally, I cut the radius on a
ing. For those following along and using shaper table with a 12” radius cutter. For
the tools on hand, many of these opera- some operations a CNC will be faster, but
tions will have to be rethought since I am that ultimately depends on the operation,
performing as much of the process as pos- tool capacity, machinery and the mind.
sible with a CNC router.
This step requires that I rout the fretboard
radius. As a workaround, pre-slotted and
radiused fretboards can be sourced from
various suppliers, or you can rearrange the
procedure to fit your needs. I approach the
radius with a .500” ball nose cutter.
I use a . 125” end mill for a Fender-style nut
slot, up to a . 187” width for a Gibson-style
nut, in addition to opening up the adjust-
ing area for the truss rod, which is then
covered up with the headstock veneer.
offset from the end top center of the
fretboard radius to the top surface of the
body. This measurement works well for
standard Tele or Strat tremolo bridges.
Fret Slotting and Pivot Posts
For fret slotting I use a .023” end mill;
other diameters can be used for harder or
softer woods, or if your fret wire has a wide
or narrow tang. With my approach, I don’t
slot through the side of the fretboard; the
slot stops shy at about the thickness of a
bound neck, .045”. This requires me to use
a fret that has been nibbed. The advantage
here is that you don’t see the fret slot from
the side, fret sprout is rarely an issue and
Cutting the nut slot and truss access.
A quick review of fretboard radii is in
order: 7. 25” or 9. 5” for vintage to modern
Fender, 10” or 12” for Gibson and modern
Fender, and 16” or 20” for shred guitars.
Additionally, compound radii such as 9. 5”
at the nut to a 16” at the 22nd fret are a
possibility. Compound radius fretboards are
further evidence that if you can draw it, a
CNC can cut it.
For this particular model, I am using my pre-
ferred 12” radius. I am aiming for a . 170”
thick fretboard edge, but with my approach
this isn’t easily measured until the neck
perimeter is cut, exposing the edge. Since I
have this as a CAD drawing, it is something
easily adjusted, but back in my garage days,
I would first slot my fretboard on a table
saw, then perimeter the board to final specs
on a table router with a bearing cutter. I
would then template it, utilizing 1/4” tool-
ing holes in the underside of the board to
attach tooling jigs.
Additionally, you can opt for something like
a zero fret, which utilizes a fret slot and fret
at the 0.000” origin, making open strings
sound the same as fretted notes.
Neck Perimeter and Headstock
Next up is cutting the neck perimeter and
headstock. A pin router would work here
if you don’t have a CNC, but requires
devising a key pattern to guide the router
pin where you want the cut. Since this is
a tremolo model, I also need to route the
tremolo recess at this time to utilize the
installed cutter as much as possible.
Here I fly cut the surface of the body to
a final thickness of 1.780” using a 1” end
mill. It wraps around the end of the fret-
board, where I look for a .375” height
Fly cutting the body surface
it sure looks pretty. Also, while in this posi-
tion, I use the same cutter to stab center
holes on the headstock for tuner locations.
I use a .250” end mill and drill my fret-
board face dots and my bridge pivot posts.
If you were planning on using rear loaded
electronics, you could now cut your face
That does it for this month; next month
we’re going face down for rear routing
Any questions or comments visit
Fine Tuned Instruments LLC,
home of his “b3” instruments.