Multi piece neck

There is absolutely no reason not to do a three piece neck - they are very strong and can be quite beautiful. I used a three piece neck on my tricone because I wanted the wood effects - I had planned on using flamed maple for all the trim so I ran id down the middle with mahogany on the sides.

The only thing that will be at all weird with yours is that you will have the joints running thru the headstock slot, I probably would have made the center piece thinner but I also know you want to carry that on into your neck stick. The outside pieces will get wider as they get closer to the heel and might look funny - you might want to look at that in your rendering. Also, you have shown this as a slot head which probably means you will want to put your truss rod adjuster in the body instead of the head - I did that with the tricone and provided a hole thru the cone well for a long allen wrench to adjust it. You'll also have to decide if you want a head plate or not.

Multiple piece necks are a good way to use wood that is not perfectly quartered - if you cut the outside pieces so the grain is mirrored it will the most stable. And as far as the slots are concerned, I do them on a drill press drilling out most of the waste, then chisels and rasps but a router will do too

A couple of pictures from the tricone

 

You should be aware that multiple piece joints may move over time due to the different grain directions and densities among the various species. You may end up feeling and seeing the glue joints telegraph through the finish.

Gibson Les Paul Uneven Seams on Body | The Gear Page


Obviously there are a lot of multipiece necks out there... but this way you know in advance that it can happen. I try to minimize my wood joints in all my guitars as I don't have climate controlled conditions to work in. I use quartersawn lumber in my necks and shy away from timbers that have a high dimensional instability.