Adjusting Saddles To A Compound Radius?

Discussion in 'Luthier's Guitar & Bass Technical Discussion' started by dumb donnie, Oct 6, 2005.

  1. dumb donnie

    dumb donnie Member

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    If the neck radius is, for example, 7.25" to 9.5", how do you radius the saddles? Would you just set them somewhere between the two?
     
  2. rooster

    rooster Member

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    I believe you'll want to set it to the bigger radius.

    rooster.
     
  3. GuitslingerTim

    GuitslingerTim Member

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    Assuming the nut is radiused to match the first fret--as it should be--the saddles should be set to a similar radius that matches the last fret. When I say 'similar radius' I don't necessarily mean the strings should all be the same heigth from the frets. I like action that has each string gradually higher than the previous string, starting with the 1st string.

    If you're thinking of modifying the saddle slots on a hardtail bridge, it's the worst option. I always recommend that a strat or tele style bridge with adjustable saddles be used on guitars with a compound radius fingerboard.
     
  4. Roe

    Roe Member

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    Actually you can try a little bit more than the bigger radius.
    If you want the strings to follow the fretboard so that it/they keep getting flater and flater, it will have to be flater at the bridge than at the 22 fret.
     
  5. CharlieNC

    CharlieNC Member

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    yeah, just a quick reply, don't even worry about the compound radius when setting string/saddle height. just capo the first fret and measure the distance from the bottom of each string to the top of the 17th fret. adjust each saddle so each individual the string is 4/64" from the 17th fret. be sure to retune everytime you move the saddle and measure. oh yeah, doing it this way, your string height will mirror the curve on your fretboard. hope this helps.
     
  6. Roe

    Roe Member

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    that's a good tip!
    But you might want to have a higher action on the bass strings than on the high strings.
     
  7. dumb donnie

    dumb donnie Member

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    Many thanks for all the responses.
     
  8. Clorenzo

    Clorenzo Member

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    Since the radius increases linearly as you go from the nut towards the bridge, you can do a simple calculation: the last fret is approximately at 3/4 of the scale length from the nut. In your case, the radius has increased 9.5 - 7.25 = 2.25 for that length, so for the remaining 1/4 up to the bridge it should increase a further 2.25 / 3 = 0.75, which means a radius at the bridge of 9.5 + 0.75 = 10.25.
     
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  9. John Phillips

    John Phillips Member

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    :confused: :)

    Just set it so it plays right.

    What radius? No idea.

    (Although, it will be flatter than the radius at the last fret for sure, whatever the radius, and whether or not it's compound, as Tim said.)

    I've been setting up guitars professionally for twenty year now and I don't own a radius gauge of any kind and never have. Completely unnecessary IMO.

    Set the action on each string so they don't choke or rattle when bending hard above the 12th fret and you're done. I start by setting the top E precisely by playing it, then do the others by eye - looking across the strings over the end of the fingerboard for a smooth curve, ending up with the low E a bit higher than the top one - then check again that nothing chokes out. That's it.

    Just my opinion of course ;).
     
  10. dumb donnie

    dumb donnie Member

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    Well, that's what I was hoping to hear. I don't own one either and I wasn't too keen on the idea of purchasing one. I guess the lesson I have learned form this thread is "just set it up so it plays right". :D
     

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