I need to make a torsion spring including the attachment ends.  The path is fundamentally a helix, with relatively simple geometry on each end for the attachment points.  When I try to sweep a profile along the needed path, it will not follow along the full needed path.  So, I need to combine everything into one entity with 'Fit Spline' if I want one continuous sweep.

I have gotten a part that looks 'acceptable' by taking the ends of the helical sweep and then sweeping those out to the ends, but it looks pretty lumpy near the joints.  I am aware of and have selected forcing tangency at the endpoints (I have a hard time imagining when you wouldn't want this incidentally).

Is there a superior method to get one long entity, or have I missed something?  The attached file is in SW2015.

Thanks in advance...