I've looked at the Solidworks help, and it plainly says that you can define loads and view stresses relative to a local coordinate system
Local Coordinate Systems
Local coordinate systems are coordinate systems other than the global coordinate system. You can specify restraints and loads in any desired direction. For example, when defining a force on a cylindrical face, you can apply it in the radial, circumferential, or axial directions. In this case, you need to select an axis as a reference geometry.
Similarly if you choose a spherical face, you can choose the radial, longitude, or latitude directions to apply restraints.
When viewing results, you can also use reference planes and axes. For example, you can view stresses on a cylindrical face in the radial direction.
Fair enough. Just how do you do this? I see I can define loads relative to a cylindrical system, if those loads are defined as irregular. I don't see anything regarding stress plots relative to a cylindrical coordinate system, or any way to define a cylindrical coordinate sytem.