Official Luthiers Forum!

For all of you experts out there I have another question.Everytime I build
a guitar the fret board extension always has a small between the top and
the bottom of the FB. The neck fits perfect and the neck angle is right on
the money.The FB itself is good and straight, so I don't know why I always
have this gap of approximately 1-1.5 mm.If I lessen the neck angle to
minimize the gap then I will end up with too thin of a bridge and an
action that won't play well.If I glue up the FB to the neck the gap closes
very easily and I end up with some fall away but I wonder if this is normal
to have this gap over the body above the soundhole? Please let me know
what you think.

Thanks ,Steve

Todd, I build my tops with a 30ft radius and when I do my bracing I keep
the braces above the soundhole flat so the top will be flat in that area.
Steve

I'm always careful when sanding that are as sometimes i tend to round it a bit when sanding....

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Peter M.
Cornerstone Guitars
http://www.cornerstoneukes.com

Got to be the neck angle doesn't go with your radius. I use 1 1/2 degree angle with a 28' radius and, so far, I have no gap.

Ron

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OLD MAN formerly (and formally) known as:

Ron Wisdom

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

Steve, is the gap at the binding edge? I think this maybe what Peter is talking about, if you round over your bindings under the FB ext, you will get a small gap right at the join, the other possibility, is that your sanding and rounding the bottom of your fretboard ext while you are sanding its edge, removing the sharp edge.

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Lance@LuthiersForum.com

Steve, if the neck is set to the correct angle so you have to correct amount of gap at the bridge, DON'T CHANGE THE NECK ANGLE.

Take a look at another great Heshtone tutorial on truing the upper bout. This may help.

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Lance,
The gap is not at the binding edge.It is a good tight fit there.The gap
starts to open as you get closer to the soundhole.Atat point the gap is
about 1-1.5mm.The top is nice and flat where it meets the fretboard
extension.

Steve H.

Excellent advise Todd, as with everything in the world of Lutherie, there is no ONE right way, there is only the right way for YOU!

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Lance@LuthiersForum.com

Thanks to all of you for all the helpful comments.I'm not exactly sure
what to do to solve the problem at this point, but you have given me lots
to consider.
Thanks, Steve H.

My situation is the same as Steve's... tight at the binding and the fingerboard is up off the top a little at the soundhole. I just clamp it down!! After the glue is dry I level the fingerboard, usually taking a slight hump off over the neck block. Everything comes out nice that way.

I radius my braces to 30' and the rim to 47'. I don't flatten the area where the fingerboard glues down. Seems to work fine. 96 guitars and counting...

Mark

Mark,
Why the 47ft radius on the rims and 30ft radius on the braces?I've only
built 5 guitars and that is a new approach to me.Please elaborate if you
would please.

Thanks,Steve

Steve

It just seemed to make the geometry of the whole guitar to work out a little better. I was having some problems with the fingerboard extension  having a gap near the binding when I used a 30' radius at the rims. The top seemed to be curving off too much. Going to 47' reduced that curvature and made it fit better. I could probably have fixed it by reducing the radius on the upper transverse brace, but I didn't want to do that. I like having some arch there.

It also makes is easier to fit the bindings !!

Mark

I've seen a photo somewhere...can't recall where...on a bolt-on neck
instrument with a small allen screw that runs through the transverse
brace and into an insert epoxied into the underside of the
fretboard.  Just screw it down flush to the top.  I may try
this on my next.

[quote=HeshI956]I read one comment above and felt genuinely hurt and wonder why any one would want to expose OLFers to any more hostilities...... I certainly don't. [/quote]

    Hesh, my friend, there are a lot of people that use the MIMF! Yes, Yes, I hate people exposed to it too, but there's a lot of info there. This what you were talking about, ight?

     I think Todd was... judicious, recommending somebody, "go to the MIMF archives"! I also really appreciate your warning about the general culture too.

    Thanks Bud!

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Billy Dean Thomas
Covina, CA

"Multi famam, conscientiam, pauci verentur."
(Many fear their reputation, few their conscience)

IMO .. its all about geometry here - Michael Payne had a CAD dwg of a guitar with a 28 foot top, radiused upper transverse - the geometry works out perfectly to give a string height above the top of 1/2 inch, with good action, and a 3/8 thick bridge (this is what I shoot for, and how I do it). If you now take that same 28 foot top, and flatten the UTB - you have only one choice if the FB lies flat, and that is to make the saddle/bridge combo thinner. If you are using a 30 foot top radius, and flattening, and still looking to get the 1/2 inch string height, it makes perfect sense to me that you will have a gap under the FB at the soundhole - the top is too flat with respect to the top curve at that point. Stop flattening the UTB and most of you issue will disappear IMO .. you may still be a touch under the 1/2 inch string height above the top though.

_________________
Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"