"Slightly mortised butt heel"

[John Parchem]

Thanks for posting! There is a lot to think about in the neck\body joint you are showing in your pictures. I like the idea of a full bolt on neck. You ended up with a good looking solution.

[ken cierp]

Personally I am not convinced that there is a need for all the hefty extensions on the neck itself -- seems the main purpose is to provide a surface for "T" nuts? I've taken a little different tact and simply added fasteners to the fingerboard extension -- however still in the prototype stage.

[Dave Bagwill]

Ken - do you think the mortise is necessary? If so, how would one arrive at a useful depth? Anything to add to what penndan contributed?

[ken cierp]

The mortise is necessary in my scheme since I plan to have an adjustment ability relative to the neck set angle. Normally I just allow the FB extension to compress against the sound-board. This set up is a bit more complex since the neck can be tilted forward or back and the mortise will still mate perfectly with the neck heel appearing to be a flush fitting joint.

[Dave Bagwill]

That sounds like a tricky bit of engineering, it will be very interesting to see how it turns out.

For something simpler, like what I am going to attempt, is the mortise still necessary, and if so, is the depth that critical?
Would the cheeks of a butt joint be left untouched, and the rest hollowed out a bit, as the cheeks of a m&t? (You may recognize this picture) : if you remove the tenon, yielding a butt heel, would you still hollow out the xxx'd area?

[ken cierp]

Not much engineering -- more like a lot of copying Taylor!

Your thought is correct -- the old Vega's with the doweled neck butt joint have a fairly deep recess and only touch on the edges of the heel.

[Dan Pennington]

I did not hollow my neck heel. My neck block was flat. And after I scored the outline of my heel on the sides, I used a router to mortise the sides, so the bottom of the mortise was flat.
I cut my neck extension at 9/16 thick so it would have enough thickness to provide a tunnel for the two way truss rod and carry the carbon fiber rods out under the fingerboard extension. Probably don't need CF rods under the FB extension, but since they were going in that direction, I brought them along.

I wanted the neck mortised, so that when I have to change the angle of the neck, I don't have to do all the fancy heel cutting and flossing.