Working with round parts in a section view, or side view so to speak

Greetings All,

First, I am probably not going to explain this the best so please bare with me.

For many, many years of 2D design, I designed using section views. What I mean is, if I was working with round parts I would do all of my layout design work using the section view.

I have been trying to do the same thing in SW for design and drawings and I often have issues.

For example, I am designing a tool for a customer part that is round. I created a sketch in the front plane which basically is the side or section type view. No, it's not really a section in the true sense of the word section, but I think you get the point. In my sketch, I want to create some lines that will be revolved but I want the lines to be colinear to the outside diameter of the customers part which in a side or section view would be an edge but it's really not an edge in the model.

I have gotton mixed results when doing this and I am wondering if anyone can help me understand what's wrong or how to do this the right way.

So in other words, I am often trying to get lines that are really not there since they are diameter features but in theory they would be segments in a 2d projection.

Am I making any sense? (See attached)

Thanks All.

SolidworksParts And Features