By definition, 2D centerlines always requires the selection of two objects, either points or something like a pair of circles representing the 'ends' of the 'cylindrical' shape being drafted. Even when creating them, the user has to make two selections. Now with 3D centerlines, only a single selection of a cylindrical face needs to be made. So perhaps, if it's practical, rather then reassociating a 2D centerline you could simply delete it and create 3D centerline in its place.
John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA Siemens PLM: UG/NX Museum:
To an Engineer, the glass is twice as big as it needs to be.
