arch top how to align neck,neck block and end block

[richard kacsur]

I'm working on my first arch top and getting ready to install the neck block.
How do I make sure the neck (when attached) is perfectly in line with the end block and doesn't cause the bridge to be shifted over and have the strings off center from the finger board???

Thanks !!!

[Brian Evans]

You mark a perfect center line on the fretboard and use a long straight edge to align the neck with the center line of the body. It all starts with the mould you make the body in. I mark the center line of the body on the mould, so that when I put the sides in the mould and glue up the end blocks, I have a perfect joint between the sides on the exact center of the body. Then when I glue on the top and back I align the center seams with the seams on the sides, so the seam on the top is perfectly aligned with the seam on the sides. Then I cut the neck mortise and make sure it is centered. I cut the neck tenon ditto. The final step is to align the center line you marked on your neck with the center seam of the body when you do your final neck set. A large part of setting the neck is perfecting the angle so the string height over the body is correct, and aligning the side to side angle so the neck is in line with the center of the body. It's that whole series of steps keeping everything about the body and the neck symetrical and aligned that makes the neck alignment come out perfectly.

You also use that perfect center seam on the body to locate your F-holes symmetrically if you are using F-holes traditionally.

[Randolph Rhett]

I’m not 100% sure I understand your question. The head and tail blocks don’t necessarily have to be in any tight alignment. You generally cut your neck dovetail after the box is closed up. Assuming you’ve used two pieces of wood for your top, the seam will define your center line. The mortise would be cut centered on that seam, like any guitar. The left/right tilt of the neck would be adjusted by the cheeks of the heel, again like any guitar. Nothing unique about the neck alignment on an archtop.

[John Clifford]

In addition to what Brian said, it will help a LOT to make sure that your neck block and the area of the sides that overlap it are perfectly flat and perpendicular to your center line in the area that will be covered by the neck joint. You have to pay attention to this beginning with your body mold, and on through bending the sides, shaping the neck block, clamping and glueing, and final sanding. I mean, it is possible to get the neck properly aligned even if the joining surface is curved or irregular, but it's a lot harder.