I am trying to model this part.  I believe what I want to do is sketch the shape shown by the section cut out and then do a revolve.  When I try to model that 40 degree angle it ends up not looking right at all, maybe I am missing some relations to keep it in place?  I am starting to figure this all out, but I still feel I need to work on design intent.  Can someone give me some pointers as to where I need to start to get this right?  Im guessing it wont take that long once I get it going.