about the dovetail neck joint

[Robert Smallwood]

Hi. I am going to make an arch-top - starting with the neck - using CNC where feasible.

Starting with the neck - I am separating three dimensional surfaces from planar surfaces in order to use fluting or perhaps moulding cuts rather than 3D modelling cuts.

It seems possible to orient the model to do the dovetail with no undercuts ie all planar surfaces and then modify the resultant tool radii if necessary, but - it occurred to me - purely from the cnc perspective - why not cut the dovetail itself in isolation - ie as a separate piece - and glue and screw it to the neck heel?

This would allow easy machining but also the ability to work with the neck heel and the dovetail easily prior to assembly.

What are the arguments against doing it this way?

Thanks,Rob.

[Darrel Friesen]

I personally don't see any reason why not but I'm no expert. I did dovetails on my first three archtops but switched to bolt-on and won't go back.

[Robert Smallwood]

HI. are their diagrams of an archtop bolt on? I thought it would be impossible through the f holes. Can you suggest where I read up on it?
Thanks.

[Karl Wicklund]

I took my first forays into guitar building with a gentleman who did just that. On the bandsaw, he cut the tail right out of the neck block before installation. After he refined the neck angle, he bolted the tail to the neck.

It wasn’t elegant, but its held up for these thirty years.

[Bob Ionta]

I made an archtop with a bolt-on neck. I had to make a 2 ft. long Allen wrench that fit through the hole for the end-pin jack (for a floating pickup). Once I got that thing made it was easy enough to insert the bolts and tighten them through the end-pin hole.

[Robert Smallwood]

Thanks! There's stuff to think about here )

[Alan Carruth]

A number of Classical makers use a floating tenon the join the neck and body. The heel is cut to butt at the correct angle, mortices are made in both the heel and neck block, and a wood tenon goes into the mortices to locate everything. These are usually straight mortices, but there's no reason you could not use a dovetail on one or both sides.

I usually use a single tapered mortice to join the neck and body on archtops. On the plan view the sides of the tenon are parallel, but it's tapered on the end view, with the upper end wider, like a Martin dovetail. It goes together and comes apart the same way as a Martin-style dovetail, but doesn't draw in by itself. I went with this because I was concerned that a plain straight tenon would swell as it was being steamed off, and lock in place even if the glue was soft.

[Darrel Friesen]

HI. are their diagrams of an archtop bolt on? I thought it would be impossible through the f holes. Can you suggest where I read up on it?
Thanks.

I install a dowel from top to bottom through the tenon on the neck to give better purchase for the hanger bolts that will be installed. Once I've carved the neck extension to the right height/overstand, I use marking punches in the pre-drilled holes in the neck block which are done during construction of the neck block, to mark the neck tenon. I then drill for and install hanger bolts (drill press for this). As previously stated, I made a 2' long Allen wrench to access the furniture nuts I use. The wrench goes through the endpin hole and then the nuts are put on to the wrench through an F hole.