The neck to the body properly. As the body has a slight contour to it and the neck is a flat surface any Ideas on what tool,or feature to use?
I have attached a picture of the faces.
Welcome to the forum. You should be able to apply a tangent mate between the surfaces.
A real guitar doesn't fit like that, it's flush or sits in the cavity. Otherwise, Glenn's suggestion of a tangent mate will work.
I agree. On a solid body bolt on neck, there is a flat surfaced pocket cut into the body and the neck heel is an "exact" match. On a solid body set neck, there is either a matching pocket or a single dovetail joint that has an exact fit. On an acoustic guitar, there is a heel block in the end of the body and the neck heel fits with a dovetail joint.
Given your displayed geometry, a tangent mate followed by a mate between a plane on the neck and a plane in the body (parallel/perpendicular) will position the neck as you want it. But please see the above. Join GrabCad and look at some of the guitar models.
And if that doesn't work well for you I would create planes in the individual parts and use them for the mates.
One of the good things about this software is there are many ways to do something.
If like Glenn suggested you use a tangential mate but if you weren't too worried about the underside of the neck slightly encroaching into the body of the guitar you could select the outer edges of the flat underside of the neck and make them tangential with the surface of the body... that would pull the neck up to the surface and visually look like they were coming together.
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