I am trying to add a bevel to hole cutouts in a pipe. It is more challenging than I have anticipated. The chamfer tool is a total fail with my attempts to get it done.

I am now trying to generate a 3d sketch curve in the middle of the pipe. I cant do it though. I am trying this so that I can create the geometry for the bevel, and use the curve as my path to do a swept cut. I attached a pic of the drawing, and I attached my model.

Any way you can figure out a solution I would highly appreciate.

Thank you.