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This is kind of another neck angle question but hopefully with a difference so as not to bore the more experienced here.
I am in the process of fitting my first neck.
With a domed (25') sound board there is an angle created with the sides at the neck join that is greater than 90 degrees. I understand about setting the neck angle to get enough clearance at the bridge but then if this differs from the angle created by the soundboard how do you adjust so they fit nicely.
Or should these 2 angles be the same in which case you can just fit the neck cleanly to the guitar and then use the resulting angle and compensate with small changes to bridge height if needed.
Cheers
Dom

Thanks for the thread Hesh. It tells in detail the whole issue. It is all slowing coming together in my head and I figured in a well designed and constructed guitar the radius of the top should be designed to give the correct angle and so adequate height at the bridge for enough string break etc.

So this idea was kind of like an epiphany to me (but maybe boring to the experts) but if you wanted to change your height at the bridge without getting fret board humps or dips for a particular design you would change the radius of your top. Is that how people here would address this?
Dom

Now I didn't go look at the other thread so maybe this has been discussed over there.

The one thing that many first timers don't realize is that you want the set of the neck (neck angle) to be based off the height of the bridge, not the angle at the body. This is were good design comes into play.

[quote=Dominic]So this idea was kind of like an epiphany to me (but maybe boring to the experts) but if you wanted to change your height at the bridge without getting fret board humps or dips for a particular design you would change the radius of your top. Is that how people here would address this?
Dom[/quote]

Yes, if the height of the bridge changes the angle at the body/neck junction needs to change. There are a couple of ways of doing this. One would be to change the dome/arc of the top. Another is to sand the upper bout above the soundhole to get the correct angle between the top and sides.

So as you have learned, the neck set is all based on the bridge height. One thing that I've heard quite a bit from the newbies (not that I'm not still a newbie, but I've read so much that I feel like a professional newbie ) is that they figure they would just sand down the bridge or put a shim under it to get the height right when it's in the body angle design that should be changed.

Laying out the design profile full size on paper or in a cad program can really help put the entire building process into perspective. Even better is a 3D model of it. Michael Payne has in the past posted some great renderings of guitar designs in 3D which have aided in his design process.

Enough rambling now.

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Dom, don't worry to much about the angle of the neck heel, that angle is insignificant as long as your joint is tight. All you need worry about is the geometry of the fingerboard/bridge alignment, and of course you want the fingerboard to sit on the top at the upper bout without any gaps so that is the place to start. I don't use any fancy alignment jigs or anything, I just contour my sides with a sanding dish as most others do and then start working on the upper bout with a fairly large sanding surface (block large enough to cover the upper bout) sanding it flat from the neck block to just about the waist(maybe slight forward of the waist. Using a 25 ft radius then sanding this area flat gives me just the right height of an extended fingerboard coming out about a 16th over the top of the bridge, my bridge is 5/16" tall. After you have attached the top you can fine adjust the fingerboard glueing surface as Hesh has demonstrated. Then as you make your neck, make your neck/heel angle fit the angle you have created on your box. It does not matter what this angle is as long as your fingerboard/bridge geometry is correct.

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Thanks guys. I appreciate you 'pros' taking the time to talk about these mundane issues. It helps to be able to test my thoughts and get feedback. As I learn I hope my questions become more challenging and insightful.
Cheers
Dom

Rarely do I have to sand the tops upper bout much at all to achieve a good fit between the FB and the top with the FB on proper plane with the bridge. That said I did a bunch of sanding in the early days till I laid out the geometry and figured out how to eliminate the majority of the needed sanding. The key was the radius of the dome and proper positioning of the center of the dome in relationship to the top. If the apex of the dome is too far forward the angel set is to shallow. Too far back and the angle set by the dome is to steep.

I fit the neck/FB first and radial sand the bridge to achieve close to proper FB/Bridge relationship. I set it schoosh (as properly defined by Robbie O'Brien)high. Once the neck and bridge is fitted I fine tune by sanding the FB on plane prior to fretting. I use the long aluminum StewMack precision FB radiusing sander to do this. Yes this is labor intensive but allows be to make exacting adjustments. And also removes the dreaded 14th hump if it by chance does happen. Which is almost never any more. This requires that I fret the FB after all construction is complete. If you fret prior to installing the neck you cant use this method.

I guess I should say that the body length will make a difference in the angel formed by the tops dome. So you need to adjust the location of the dome apex according to body length and scale length. I use 25' radius on all tops over 19 15/16-21" body length with 25.4 scale FB (14 at joint). This leaves very little to sand the to at the FB for a good fit. Smaller bodies and shorter scales require some sanding near the sound hole to make the neck/FB fit right. longer bodies may require sanding near the neck joint. But not much.

did not mean to post again