I am trying to make a 3D model. It consists of a cylinder resting on an extruded ellipse as you can see in the picture below. I now want to join the top edge of the ellipse with the top edge of the circle. In a sense, I want there to be a chamfer between the side surface of the ellipse-prism and the top surface of the cylinder. However, I don't even know what tool to use. Is it a chamfer? Is it called something else? The problem is that the distance from the cylinder to the edge of the ellipse changes depending on whether you are looking at the north/south/east/west sides.
I am using Autodesk's free 123D design software.