Official Luthiers Forum!

I know I'm full of questions lately but there's a few things which I would like to find out, one of which is about fingerboard radii. Is there a "traditional" radii for a fingerboard on steel string guitars? I regularly see fingerboards with a radii between 12-16" but what effect does this have on the guitar? Is it purely a comfort thing for players or does it have in impact on anything else? In a book I have the author states that over the years of making guitars the easiest to work with are a radii of 12-14" but he doesn't stat his reasoning behind the comment.

Peter: Basically two way to radius a fingerboard. One is with a constant radius the full length of the board similar to a section of a piece of pipe. The other is a varying radius from nut to sound hole end of board.For this imagine a section of a cone. Some players are very sensitive to the parameters of the board.The varying radius board allows a lower set up and some players are after this type of thing. The varying radius is a bit harder to accomplish depending on how you do it ie. by hand. If done by certain jig set ups is very easy to do. Don't think the amount of radius causes a problem in building other then with the depth of cut of the fret slots especially for bound fingerboards and this is only in extreme cases. More important to do what the customer wants in my mind or if for spec do average radius. Am not sure if there is something in the tutorials or not but surely lots on the net if you look. Good luck.
Tom

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A person who has never made a mistake has never made anything!!!

It should be mentioned perhaps that the "cone" type, or compound radius fretboard (which I am using), fretting is a little more tricky in that frets must be hammered in or you should have a large selection of fret press radii available, Also, more a little more care is required levelling the frets to maintain the radii.
Fret slot depth is not a problem if using a depth guide like Stewmac supply.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

If you use a sanding beam that is not as wide as the entire neck such as the Stew-Mac radiused beam you will end up with a compound radius. This is what I do even though I have the Stew-Mac radiused sanding beam.

As Colin indicated you can either hammer or press frets but for compound radius fret boards you will need a selection of fret press cauls if you are pressing. The last guitar that I built I used a compound radius of 16 - 20 and pressed my frets.

Leveling is no different than what you did to level the fret board again using a leveling beam that is not as wide as the fret board. These days I use a leveling beam that is only 1" wide and my technique with this beam is to mimic the string path when leveling.

Here is my John Watkins fret press caul set:

"I get variable radius (as opposed to compound, which would be two radii)."

Thanks for info Todd.
Strange, I've never seen that type of fretboard refered to as anything but compound radius, compound meaning of course two or more.
Variable would seem to imply that the radii could be varied by the user.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.