I'm trying to place an optical lens (file attached) at a certain distance from a point or plane. The lens has a curved surface and I need to place the edge of the curved surface (see diagram) at a certain distance from some object (a point or plane). When I try to mate the curved surface with a plane then I get an error. If I try the same thing with a point I do not get an error but I don't think the placement is where I want it to be.
Any ideas how this can be done correctly?