Well I finally sorted out the loft modifier in 3ds Max and have nearly finished the neck.The process was fiddly and exacting but some patience and a few hours got it sorted in the end.
The pieces fit on the print bed diagonally
How I did it.
First I made a spline the length of the whole neck.Then I made the cross section of the thickest part of the curved neck. This ended up looking like an oval cut in half. The curved spline had a lot of vertices along it something like 15 or so to describe the half oval. While probably not necessary I then took that half oval and moved the vertexes into a rectangle pattern to describe the heel of the neck along with the head stock.
I ended up with about 6 shapes based on one half oval so they were clones of one shape but were arranged and sized differently as well.
The reason for this was I wanted all the shapes to have the same vertex count as I had nothing but problems and strange results with using the normal 4 vertex rectangle shapes you can make in Max when I tried to loft them together with the odd vertex numbered half oval shapes.
You can loft using a number of techniques in the loft modifier. You can use a percentage along a path, or steps along a path (the one I ended up using) and one other method.
The method I chose was to take one long spline and where I wanted a particular shape to be applied along the spline I measured along it and placed a vertex. This way I could just jump to each vertex location and loft in the required shape.
Once I had the flat neck finished I then angled the head stock down 10 degrees and Booleaned out some machine head holes and added my logo again.
I'd somehow miscalculated the thickness of the neck heel that sits in the pocket of the body so I just fixed it on the fly, by dragging some vertices to the measured correct location.
All I have to do now is to slice the neck into sections for 3d printing. The neck is about 410mm in length as it is now and will need to think on the slicing method and the angle of the slice and the length of each piece, so people can fit it on their printers.
This neck will need a fret board like this Tenor ukulele fret board on ebay.
They are cheap and have a little extra timber near the nut for trimming to the correct length.
You are going to need a nut as well so buy one while your at it. It will have 4 slots and be about 35mm x 6mm x 6mm.
...........and some machine heads