Topnut
There can be different reasons to replace a guitar or bass topnut:
- Damage
- After replacing the frets (refret)
- Adjusting the string spacing
- Adjusting for a certain string gauge
- Change the material of the topnut (Graphtech, brass, bone)
Every topnut has to be made in a way the instrument plays comfortable, detunes as les as possible, makes no unwanted sounds and plays in tune around the open chord area (first three positions).
Changing the topnut of a Fender stratocaster
To be able to refret the neck and to make a correction in the shape of the fretboard, the old topnut is removed. The old one was made from plastic and the owner of the guitar prefers a bone nut.
On the photo, a piece of bone is cut to size, and the string depth is roughly marked with a cut in half pencil.
With a fine pencil, first the two outside strings are marked, keeping in mind how far the string needs to be from the edge of the neck. Someone who uses his thumb to fret the low e string might prefer the low e string closer to the edge. Someone who plays solo with lots of bending might want to have the high e string a bit further from the edge of the neck so it does not slip away.
A deviding ruler is usualy used to devide the rest of the strings.
The first cuts are made with a very fine edged file. This makes the precise position of the string.
The string slots are cut with diamond files with different thiknesses. Te slots are cut towards the pencil line.
The height of the topnut is sanded at the same radius as the fretboard. Material is removed in a way that strings are seated wel in the slots, but not to deep to cause extra friction.
Also now the player of the guitar is keeped in mind. Someone who does lots of bends at lower positions needs to have the treble strings a touch deeper in the slot so the are not bend out of the nut.
During the sanding, dust is removed by a vacuum cleaner.
The topnut is shaped further with files, sandpaper and polish paper to avoid sharp corners and to get a nice appearance.
The string height is checked with feeler gauges by pressing the string at the 3rd fret and feeling the space between the first fret and the string. Where needed, the string is cut deeper.
The final result.
