How to make a straight side on my piston ?

Hi, I'm trying to make this piston in solidworks : http://imgur.com/a/OXITw
There are a lot of nice tutorials abound round piston but as you can see on the 4th picture, the bottom of my piston isn't totally round. Do I need to make a fully round piston and then cut it or is there another way ?

1 Answer

I would make this using the loft feature with guided curves.
make a few planes and at every plane sketch the required section.