Flat or radiused neck block?

[NeilG495]

I’m afraid I couldn’t live with the thought of a wedge under the fingerboard so, come what may, I decided to have a go at removing the top. Hot air gun and white vinegar softened the Titebond enough to allow a very thin spatula to work around the top. Not pretty but it’ll clean up with some scraping and at least I can resand and get the correct radius. Another huge learning experience and an error I won’t make again. Many thanks again John for the useful info.

[John Parchem]

I over radiused the rims before. That is why I had the information that I do. Without the top on I use a sanding board that goes across the guitar and reduce the angle from the neck\body join into the waist. Now on all of my guitars I build I clamp on the top and check the angle of the upper bout before gluing on the top. For my first set of guitars I always thought about setting the neck angle when working with the neck, but just as important is to set the body angle as the upper bout is on the fretboard plane. The neck can then be made to fit the body. On the body too steep of an angle will create a ski ramp of the extension, a bad situation. Too little will create a hump at the body join when the fretboard extension is forced down to the body. Too much angle on the body can make the guitar unplayable, too little just stops playing past the body join.

[NeilG495]

Cumpiano doesn’t really explain that too well, yes he shows the importance of the neck angle and the relationship to the clearance at the saddle, but he glosses over the top radius. It’s been a valuable lesson for me and that 2.5mm dimension is now burned into my memory. I have a couple of questions on the bolt on neck (having only used the wooden taper pins), I’ll head over to the correct forum section to post them. Cheers.

[John Parchem]

Here is where my 2.5 mm comes from. On a steel string I like the strings to end up about 14 mm from the top.

So here is where the 2.5 mm comes from 14 mm = 2.5 mm + 6.5 mm (fret board thickness) + 1 mm fret height + 5 mm (2.5 mm action at the bass) -1mm for string tension.

So you can see where not mixing comes into play even here you would adjust that height depending on your target string height, and you fret board thickness. But on a normal guitar 2.5 gets you close.