Official Luthiers Forum!

I'm one of those geeky classical guitar makers who is trying to broaden my horizons by making my first steel string. My question seems pretty simple but I haven't been able to find anyting that adresses it.

I've made my mortise and tenon joint so that I have the proper neck angle (about a 2mm gap at the saddle point). My question is: how do I get the fretboard to lay flat if the neck is not on the same plane as the body? I've never heard of anyone using a shim under the fretboard. Is the angle small enough so that it doesn't matter? Am I missing something?

Dave- What radius is your top ?
If you made a real FLAT top then you may be out of luck .
A shim would be needed then.

The radius makes the top curve into the neck-so they can line up together.


Mike Collins

_________________
Mike Collins

Mike,

I didn't radius the upper bout of my top. In Robby O'Brien's video, he says that radiusing the upper bout is optional and he prefers not to so that the fretboard doesn't lay on a curved surface. I guess that's a lesson learned. Thanks for the tip.

David, it is correct that radiusing the upper bout can cause problems. But it still needs to be angled at the same degree as the neck. If your top is actually flat (not raduised or angled) your options are pretty much putting a shim in. If it's an ebony board, it won't show up at all and will be a perfectly good fix.

    I do things this way. I radius the top and flatten the area of the fretboard extension. I just complete a guitar this weekend and other than setting the neck to depth I had no adjustments to make. The string height will be .500 on the saddle. That to me is perfect action height with the 12th fret height of 3/32 on the bass side.
     This is one of the areas of building that is all based on technique . If you have a god one that works don't change it. For those that can't get this you will be needing a ,luthier disk , 28 foot and learn to radiius the top. The amount of curvature is so slight that the top will flatten to the fretboard .
     john hall
blues creek guitars

Thanks guys, great suggestions. BTW, I used a 30 ft radius on my top but kept the upper bout flat. John, I have a question about your technique. How do you flatten the top in the area of the fretboard extension after you've radiused the top? Do you just sand it flat or is there another method to flatten it out?

I mark the area of the extension , then using a sanding block and chalk , mark the area with the chalk and when the chalk is removed I have a flat and true surface where the board lies
john hall

You can use a wedge-shaped shim underneath the extension, as well. Al Carruth does.

_________________
Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

When I sand the radius into my upper transverse brace, I mark it like John said above with a pencil, I stop sanding when there is about 2 1/2" of marks left in the center. The brace is radiused on either side and flat under the FB.

Ron

_________________
OLD MAN formerly (and formally) known as:

Ron Wisdom

Somewhere in the middle of Arkansas......

You flat-top boys really do need to carve the underside of the fretboard to fit the top precisely like an archtop.
(Runnin' and duckin')

Hesh,

If I understand you correctly, you're saying that when using a 25' radius for the top, you find that raising the tail block 1/8 inch when sanding the upper rim with the flat board gives you the correct angle for your fretboard to lay flat on the top? I like the simplicity of that approach.