Radiused fingerboard

[bluemtgrass]

Well, does it ? Or can I simply let my old bridge alone ?
And I'm assuming one has to likewise radius the nut to the same radius as the fingerboard...

[Stephanie Reiser]

Yes, to both questions. BTW, to what radius is the fretboard?

[tope]

Yes you are correct you need to have the bridge the same radius as the fingerboard if you have the same radius the lenght of the fingerboard. The grooves on the nut need to be cut to also match the radius. A compound radius board (tighter radius at the nut than at the 15th fret) is a diff. animal and can have a less radiused bridge that the fingerboard.

[Gavin Baird]

These are tricky questions; for the radius at the nut is dictated by the clearance you have at the first fret with the string fretted at the 2nd or 3rd fret. That being done, I suppose that the string complement will follow the F/B radius. The most important thing is the clearance not the radius. With regard to the bridge; the same thing applies with respect to the clearance of the strings over the 12th fret...G

[Paul Hostetter]

I don't agree that the bridge radius must necessarily reflect the f'bd radius. It's quite dependent on the player's pick attack, and this can vary quite a bit. As is often the case with violins, the middle two strings often need more distance from the board than the E or the G because people can tend to dig in harder on them. (This is often true on guitars as well.) Some folks really hit the G hard so the ideal setup is almost a straight bridge, where the G is quite high. My default setup for newcomers to radiused boards is to approximate the radius of the board, but it can change from that in surprising ways.

[bluemtgrass]

Amanda, this is a pre slotted board from stew mac
radiused at 12 degrees. First project of this type. As an
afterthought, I dont suppose this would impact the tonal range of the mandolin any ?
And as someone else noted, I am one who really whacks
the bass strings on the mandolin if that makes any difference.

[Stephanie Reiser]

12 inch.
the major difference you'll find will be ergonomical.
A very slight rounding of the bridge if you want to, and definitely some at the nut to match the board.

[Yonkle]

After re-reading thread, GAVINS thoughts are what I am thinking. When the term "Radius the bridge" is used, does this mean, "just adjusting the string height at the bridge to compensate for the radius?" #Or or you talking about actually sanding the bridge top so it has a curved top radius like the fretboard?? #If meaning actually sanding the bridge to a radius, would you just get the strings slots the right height and then sand down the bridge until the strings are sticking out of the slots the proper height, which would cause a slight radius in the top of the bridge??

I am doing a 12" radius on my #5 mandolin, ready to start, I wondered the same. When slotting the nut, wouldn't you just slot the string height in accordance to the 1st fret the same way you would on a flat board? When all strings are at the action height you prefer, they would have a slight radius naturally just from measuring string height to the 1st fret. Then I assume filing down the nut top to the look you like and the strings 1/2 way in the slot of so the nut would develope a slight radius in it.
Long story short. In regard to the nut, you would do it the way you do it on a flat board and it would end up with a radius. This is my thinking anyway, if I am way off please clue me in.
In regard to the bridge, I have pondered that too, seems you would need the G and E to be a little lower than flat to maintain the proper string height over the frets way up in the 12-17 fret range. #Seems like a flat bridge would work fine, but your action would feel off campared to a flat board. #Are my assumtions right?? #I know a 12" is not too steep and adjustments in nut and bridge may be near to nothing. I have never done a radius board so if my thinking is wrong, any tips would be very much appreciated.
Another question on this topic: Fret leveling?? Do you do this the same way only with a 12" radius sanding block instead of a flat block? #Tips, tricks, precautions welcome! # # # # # Thanks JD

[Paul Hostetter]

JD – I think the word “compensate” in your phrase "just adjusting the string height at the bridge to compensate for the radius?" is troubling. It’s not really compensating. In an ideal world you need X-amount of string height above the frets to make for good action. In a curved board, the way to accomplish this is at the bridge. The end result – in an ideal situation if not a practical one – with a curved board yields a bridge with a curve that reflects the curve of that board.

Yes, you would adjust the nut slots to the first fret. You would do it the way you do it on a flat board and, all things considered, it would end up with a radius. Why would it be different?

You want to use a simple flat block, as always, to level the frets. If the board is really dressed to a 12” radius, the frets would need a slightly larger radius block, like 12-3/32”. You don’t have that block. No one does. Obsessing on details like this is a waste of time. The strings themselves describe a straight line. If you’re working the frets with a leveling block, follow the string path and you’re there.

[Gavin Baird]

JD
On the assumption that the fret board has been produced with a Radius, whether constant or compound, and the frets are installed, what I do is to fret level with a 12" long THICK [3/4"] glass level coated with 220 grit paper. The process of levelling is done with strokes that begin parallel to the edge of the F/B and move across the F/B to again come parallel to the opposite edge. This insures that the radius, whatever it is, is maintained. The whole thing about the radius of the nut and the bridge are not important for the truth lies in the clearance at the nut and the 12th. fret. If you establish these to what is what you want in terms of playability, then that is what you want. Should the slots in the nut or the saddle be too great, then just reduce their height to give the acceptable slot depth....G

[Monte37]

I love the radius'd fretboards. It just seems to make sense in my hands. But,I also use Les Paul frets. Why? It seems to allow for sound voicings, a little vibrato even, having a little deeper press.
One thing that may be helpful information is when I added the Fishman bridge pickup it had to be radiused. An important factor is that there is a minimum dimension the wood can be taken down before the pisel(spelling?)pickup loses its shielding causing buzzing. I forgot what that dimension was but Fishman told me. They were quite supportive, not like some of the local shops who didn't want to touch doin it.

[Yonkle]

Thanks Paul and Galvin. I think I understand, really simple stuff just want to be sure so I dont have to re-do things. Can someone post a close up of thier bridge if it is on a mando with a radius?? The photo will answer any other questions. Thanks JD