In a 3D composite printer, toolpaths defining fill material shells are received, as are toolpaths defining support material shells. A 3D toolpath defining a long fiber composite material curved shell is also received. A fill material deposition head traces the toolpaths to deposit some of the fill material shells or support material shells at least in part non-parallel to a printing substrate. A long fiber deposition head traces the 3D toolpath at least in part non-parallel to the printing substrate to deposit the long fiber composite material curved, concave, ring, tube, or winding shells to enclose, surround, or envelop at least a portion of the fill or support material shells.