My friend and I built a couple fretted basses and guitars many years ago. We built the necks ourselves. Fretting is not as hard as you might imagine. The basic

My friend and I built a couple fretted basses and guitars many years ago. We built the necks ourselves. Fretting is not as hard as you might imagine. The basic math for the fret positions is straightforward: each semitone lower in pitch is 1.059463 2**(1.0/12) farther from the bridge than the last. The fret wire is readily available. The nut may need to be a bit closer to the first fret than the math dictates, to account for its being a bit higher than the frets. Building instruments by hand is very rewarding.