Half semitones fretboard

[Eugen C]

Hello again

I have a request from a customer - he wants me to refret his bass and add frets between the existing ones to be able to fret half semitones notes.

How can I calculate the fret spacing?

I searched the web and I found this:

http://www.ekips.org/tools/guitar/fretfind2d/

If I put "24" in the "Calculation method" field it will solve my problem?

Thank you

[Ned Knepp]

  I sometimes use these notes in my music but, fortunately, I tune up and they disappear.

  I mentioned this thread to my wife and she tells me that there is a growing movement in classical music to use some of these atonal sounds as accents. I can't imagine what a fretboard where every fret was out of tune with the frets on either side would be like to use. 

  Kerry, did the friend you had who could play the clone actually use the, for lack of a better term, shifted key frets or did he play around them? 

[Kerry Krishna]

 He totally used them Ned. He was/is a spectacular and quite well known Canadian/Winnipeg guitar player by the name of Ron Tomasson. He was the guitar player that replaced Luke Doucet (Whitehorse/ The White Falcons/Sarah Maclauklin) in Acoustically Inclined in their later years.

You have to be able to use a different part of your brain to play those notes and it make sense. Ron made that guitar/experiment make sense... 

[Eugen C]

Update

The fretboard was flat so I made  a 16" radius.

Then, using the fretboard calculator that Jeff Highland recommended (Thank you!) I started the frets slots cutting.

First I needed a device to hold the neck and to measure the new frets placements.

After a lot of head-scratching I end up with this device:

http://i189.photobucket.com/albums/z60/eugenro2001/Guitar%20repairs...

http://i189.photobucket.com/albums/z60/eugenro2001/Guitar%20repairs...

http://i189.photobucket.com/albums/z60/eugenro2001/Guitar%20repairs...

http://i189.photobucket.com/albums/z60/eugenro2001/Guitar%20repairs...

and I had this

http://i189.photobucket.com/albums/z60/eugenro2001/Guitar%20repairs...

I put new frets only up to the 16th "normal" fret, thinking that after that will be too hard to use them.

 

Initially I wanted to leave the fretboard markers in place but in the end I filled the holes with wood powder and CA and put side markers.

I was thinking that with all these new frets, the "normal" frets would be hard to find so I put some little pieces of white binding in the "normal" frets ends.

http://i189.photobucket.com/albums/z60/eugenro2001/Guitar%20repairs...

Now I just have to level, recrown and polish the frets, all 38 of them :D 

[Alexander López]

These people have been doing quarter-tone necks for a while. Note how different it looks, instead of evenly logaritmic spaced frets, there are others installed at "half space". Weird.

http://www.freenotemusic.com/site/store/guitars.html

[Kerry Krishna]

Eugen, the way a lot of folks do the quarter tone fretboard is that after 14th fret (or there abouts) IF they want to continue it, they start using progressively smaller width fretwire.