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Very nicely done Terrence. Is that your wrench I see there for tightening the fretboard screws?John How38750.5246064815

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Tickle your guitar daily, and it'll tickle you back.

Terry;
Does the fingerboard extension pad (with the T nuts) contact the internal blocks, or is there a tiny space between the two pieces?
I've been thinking about this & will probably do it on my next project. It'd make life simpler if you could leave a little space & not have to machine a precise angle on the heelblock.
If there is a gap between, you'd sure have to be careful not to overtorque the FB extension bolts.
Beautiful work, by the way!Daniel M38750.5297337963

Great job, Terry! It really does work! Daniel -there should be a small space
between the fingerboard extension pad and the internal blocks. Just don't
overtorque the FB extension bolts!

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Sylvan
http://www.wellsguitars.com

For you guys who do this.....

If you over or under tighten the bolts in the headblock and the neck extension doesn't that change the "flattness" of your fingerboard -- not the radius, but how flat the neck is from the nut to the end of the board. I would think that it would create slight variations depending on how much pressure was on the bolts.

I would be interested in hearing reports about this.

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

Sylvan, Terry and Mayes(if you see this), is there a reason that you don't make the FB extension pad go all the way to the neck? It seams to me like leaving that 1" or whatever the depth of your tennon is, is asking for trouble. Like a hump or a dip. I put a mortise in the fingerboard surface and insert the patch into that. Thus really locking the whole system flat and straight. Any thoughts?

Brock you would be exactly right on the effect of over tighten the extension bolt if there is any gap. you would pull the extension down from the neck joint to the end of the extension. I am with Paul here it would make more since to me if the pad was inlet into the FB and flush fit to the pocket or body.

Advantage of this arrangement would be latitude in setting the neck but I would think you would want a final shim to go in to eliminate the pull down issue.
MichaelP38750.6141550926

This is what I'm talking about.

As per everything else I do, it's probably overkill.

I don't do this type of joint anymore but have been considering returning to it. When I did, first I would set the top angle so the fingerboard extension is where I want for bridge height. Then I would route the mortise in the top with the neck attahed (no fingerboard yet) and the mortise would run from the transverse brace past the neck tenon into the neck itself. The I make the insert which is just narrower than the fingerboard and leave it a little thicker than the mortise is deep. I will then install the insert glueing it to the neck and re-level it till it is flat with the top. Then glueing the fingerboard to it puts the fingerboard right where it would be if glued to the top. If the tenon in the extension is set at the correct height you will not deform the fingerboard. I agree that I like the fingerboard mortise to be attached to the neck itself not just the fingerboard.

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Tickle your guitar daily, and it'll tickle you back.

Good picture Paul, That is what I was trying to describe as well.
Terrance, where did you get that cool mirror in your picture?John How38750.6747222222

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Tickle your guitar daily, and it'll tickle you back.

One way to make sure you fretboard extension pad straight is not to make it
a separate piece. BUT make it an extension of the original block of
mahogany that the neck it made from.

You just have to make your tenon differently. I don't know if you can use
the Woolson/Fox jig
Andyazimmer138750.7425231481

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Andy Z.
http://www.lazydogguitars.com

Paul -
My development of the method I used just evolved. It started with doing
away with the popsicle brace and inserting a piece of spruce larger than the
headblock that spanned the distance from the headblock to the transverse
brace. That seemed to work well but I was still gluing the fingerboard to the
top. When I decided to try the double tenon method all I did was rout a hole
in the spruce patch as described on my website. So, I never thought about
potential ramifications as the method seems to work just fine. Granted I
have only been doing it this way for the past year so there is only around ten
guitars done with this system. But I have had no complaints or repair issues
with those in the field. I guess time will tell. Actually, yours is probably
stronger but I wonder if it really will make any difference?

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Sylvan
http://www.wellsguitars.com

Sylvan, you're probably right that it really doesn't make a difference. I'm the best at over engineering things. But for me, the reason that I moved to this system was to get far far away from any hump or extension rising issues. So I don't want to take a chance.
Andy, I've thought about making it one piece. I think it would be superior but the problem would be that it would waste a LOT of wood. You're looking at an additional 2.5" in the whole block for only 1/2" of wood used.
I think the jig could still work. You'd just have to rework the tennon fixture so that it has little "shoulders" on it at the base, then you would be routing out the cheeks of the extension tennon. I think it would work pretty well. In fact, I might give it a try.

Paul,

I've never had a problem with a hump at the body joint. I do use one
piece on the top of the block rather than two pieces there as I don't want
the neck to have a place to give and shift. Which is also why I mention in
the video it is very important to make sure the top block is firm up
against the transverse.

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John Mayes
http://www.mayesluthier.com

Paul -
Maybe it helps that I do not fret until the neck and body have been joined as
one. Then, usually I will sand the entire fretboard dead flat before fretting.
For me, this solves any issue of a hump, which, I have not seen anyway with
this method. But that takes us back to the construction of the body and neck
and making sure the top has a slight angle to line up with the fretboard
extension. It is just all interconnected and no one thing is going to solve all
of the problems. I do not think that many people really appreciate the
complexity of these boxes!

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Sylvan
http://www.wellsguitars.com

Paul, I think there is an easier way to make this work with your "tenon jig" if (not withstanding Sylvan and John M's comments) you still want to have the fretboard extension joined to your neck.

Cut the tenon as you would normally on your jig, then route away only a portion of your tenon (and not into your neck as your diagram shows).

Woops - (edit) -- Terry those are excellent pictures - nicely done sir.

Terry a couple of questions if I may. How thick is your fretboard extension and what is the gap between the extension and the extension mortise?Anthony Z38750.9321180556

Thanks for this great thread guys, very interesting info!

Serge

[QUOTE=Sylvan] Paul -
Maybe it helps that I do not fret until the neck and body have been joined as
one. Then, usually I will sand the entire fretboard dead flat before fretting.
For me, this solves any issue of a hump, which, I have not seen anyway with
this method. But that takes us back to the construction of the body and neck
and making sure the top has a slight angle to line up with the fretboard
extension. It is just all interconnected and no one thing is going to solve all
of the problems. I do not think that many people really appreciate the
complexity of these boxes![/QUOTE]


But it looks to me like every time you take the neck off and put it back on it is likely that the bolts will never have the same pressure on them and as a result the fingerboard could get pulled a little out of proportion. The wood can compress if it is too tight (even if it is just a little).

True?

I know we are splitting hairs here and we are not talking about much variance, (or maybe I am just dense ) but it looks to me like ensuring that the fingerboard remains dead flat is harder than it initially looks.

Brock Poling38751.7090162037

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

The fact that it is a removable neck does not mean that you will taking it off regularly. It only means that you can take it off without introducing the possibly harmfull effects of heat and/or water. The only reason you should have for taking the neck off is to readjust the angle of the neck in which case you will be changing the shape of or adding a shim of some sort to this piece of wood anyway. I still see many advantages to this kind of neck joint.

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Tickle your guitar daily, and it'll tickle you back.

Brock -
You make a good point as I do not know what the effect would be once the
neck has been bolted to the body, fretboard leveled, fretted and now take it
apart and put it back together. I don't think it would make much difference
as long as you tighten the bolts securely but not be a gorilla about it. Also,
keep in mind that the part of the fretboard which might be affected is the
part of the board which is the least played. I am just not going to worry
about
it; as John says this is not designed to be taken apart very often and, if a
neck reset is necessary, you may want to refret anyway.Sylvan38751.7571759259

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Sylvan
http://www.wellsguitars.com

Ok. Fair enough. That is a good point.

I am not arguing the point so much as I am trying to resolve it in my head because I think I might like to try this joint. I see some real advantages to it. I am just trying to think through where the struggles are.

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

also if you try to tighten the FB bolts down a LOT then the tenon will
break, or pop loose. They only need to be real snug. The lock washers
keep them from moving in the future. Once the fingerboard contacts the
top there is very little that can move, and if it does move it is
insignificant. Besides I like a slight amount of fall away in the board
after the body...

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John Mayes
http://www.mayesluthier.com

[QUOTE=azimmer1] One way to make sure you fretboard extension pad straight is not to make it
a separate piece. BUT make it an extension of the original block of
mahogany that the neck it made from.

You just have to make your tenon differently. I don't know if you can use
the Woolson/Fox jig
Andy[/QUOTE]

It shouldn't really be any different than adding the fingerboard extension for an archtop guitar, after the tenon is shaped, right? (I'm thinking of Benedetto's instructions). The extension just isn't the full width of the fingerboard in this case.

Jim Kirby

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Jim Kirby
kirby@udel.edu