I am more of a melodic lead player and I play lead more than chords. I prefer slim necks with flatter and low action fretboards that do not “fret out” with aggressive string bending —yet one more reason why I am not fond of the ever so popular Stratocaster. I am really inclined to build my next guitar that’s built exclusively for lead guitar playing with a totally flat fretboard, like a classical guitar. But this one is destined to be more conservative and general purpose so I’ll keep the fretboard curvature.
The question is how much curvature? The modern Strat has an aggressive 241 mm (9.5″) radius while Gibsons have 254 mm to 304 mm (10″ to 12″) radius. Modern Jacksons, on the other hand, have what’s called “compound radius fretboards” which are really conical fingerboards which start out with a smaller radius at the nut and gradually get flatter (bigger radius) towards the other end. The Jackson is definitely one of my favorite axe in my arsenal. And, for this design, I will definitely have something based on the Jackson. The radii of the curvature starts at 304 mm (12″) and ends (at the 24th fret) at 456 mm (18″).
For this to happen, we need, you guessed it: yet another router jig. The router rides on a platform that pivots on a stainless steel shaft which is oriented on an angle corresponding to the conical section with our desired start and end radii (304 mm and 456 mm). Swinging the mechanism back and forth will give you the correct radius at any given point in its entire length, thereby guiding the router over the block to be cut into a fretboard. This web article details this jig quite well: Compound Radius Routing Jig for Guitar Fretboards.
Now we sandwich the fretboard with 8 layers of carbon fiber laid up with laminating epoxy; 4 on top and another 4 at the bottom. The fretboard is vacuum bagged to remove excess resin and to ensure that there are no air pockets or bubbles that can ruin its sonic integrity.
After 24 hours curing, it’s time to slot the frets. I love jigs. Jigs make tricky tasks easy to do accurately. Inspired by StewMac’s fret slotting miter box, I use another jig for cutting the fret slots. Finally, we trim the sides using a fretboard template with a pattern following router bit.