Add real strings to a Guitar Hero controller - OpenChord.org

Step 5 Add Frets, Wire it

Now, using another guitar neck, mark where the frets should go on your neck. If you don't have another neck, the measurements from the nut on mine were
1st fret (already installed): 3.6 mm
2nd fret: 7 mm
3rd fret: 10.3 mm
4th fret: 13.2 mm
5th fret: 16.15 mm
6th fret: 18.95 mm

Insert the plug into the neck so that it fits flush with the face of the fretboard and then using the blade of a coping saw, cut thin grooves along the places where you marked. Your guitar frets will go in here.

Now, to wire up the frets. You can either just cut and hammer in the fret wire now and put the wires along the side of the guitar, or you can try to wire them from the middle of the fretboard. To wire them from the side, jump to the next step; otherwise, gently remove the wooden plug block and cut some notches in the side of it where you cut it for the frets. Cut lengths of fret wire as wide as the neck of the guitar, center them in the block, then using a piece of wood to protect the fret, hammer in the fret wire (the wood prevents the fret wire from being damaged by the hammer). Now, cut some long lengths of wire and where you cut the notches, solder one end of each wire to each fret.

If your guitar has a first fret already installed, you'll want to cut a channel from the button hole to the first fret, allowing you to solder in a wire to that fret as well. Now jump to step 7.