Set Neck Stability Question.

[Blackdog]

Dear people,

I'm already working on ideas for my second build (this is addictive !!).

It's a double-cut in the LP Special/DC shape. This time I want to go with a maple carved top on a mahogany back, and the set mahogany neck is going to be PRS style (full heel into the neck cavity).

It will have 24 frets, and the idea is to have the neck joining the body at the 23rd. Meaning that just a couple of cm into the body, the neck pickup cavity begins. The neck pickup sitting right at the end of the fingerboard.

The neck will obviously go into the body until the end of the pickup cavity, again PRS style, but will this be enough for a stable neck joint ??

In my current (first) build the configuration is pretty much the same, only 22 frets maple neck in an all mahogany body, but the neck P90 sits right at the end of the fretboard, some 2 cm into the body. It's not finished yet, I'm hoping it will be strong enough, it seems to work for PRS anyway.

But considering I will have a maple top this time, would it be advisable or convenient to extend the neck tenon into the body (under the top) beyond the neck pickup cavity ?? I know it's not simple, and that the top will have to go onto the body "after" setting the neck, but with a clever sequence of operations it seems doable.

Opinions ??

[Blackdog]

For clarification purposes:

What I'm asking is, basically, will something like this be stable enough:

Short tenon

or will I need something more like this (or something in between):

Long tenon

(Pictures borrowed without permission from Jeff Miller's website, for illustration purposes only)

Your expert opinions will be greately appreciated.

[rhoads56]

The short tenon in those pictures is still more than twice the depth you will need to built a joint that will never, ever, ever break, or become unstable. In fact, you could even not glue the sides, and it would still work perfectly fine. Remember, a scarf joint (or, for arguments sake, an acoustic bridge) has EXACTLY the same string tension trying to pull it apart as the neck does, yet no-one ever seems to be concerned about the strength of those joints, and they have less than half the glue surface area.

Remember, with nice tight flat surfaces, the glue joint will be STRONGER than the wood.

[Inisheer]

I am starting a PRS project and am planning my neck tenon off of that exact picture and was wondering if it would be strong enough. I figured that if it worked for him, it could work for me too, but I'm glad you asked this to get clarification. Although the neck tenon doesn't extend past the pickup cavity it is deep enough to go under the cavity, which gives more gluing area I believe.

[Blackdog]

I am starting a PRS project and am planning my neck tenon off of that exact picture and was wondering if it would be strong enough. I figured that if it worked for him, it could work for me too, but I'm glad you asked this to get clarification. Although the neck tenon doesn't extend past the pickup cavity it is deep enough to go under the cavity, which gives more gluing area I believe.

I think it's just a matter of peace of mind.

In the PRS bolt-on models the neck tenon and pocket are identical to the glued-on models, and the neck gets just bolted at the bottom. And it still works...

I think we're safe, then. Thanks for the reply rhoads56.

(edited for clarity)

Edited September 5, 2007 by Blackdog