Thanks for the suggestion. My problem is that sometimes it ends up beveling edges that I don't want beveling.
Here is the next step. After days of mucking around I have managed to rig the feeder line from the fuel tank at the back onto the cannon body in such a way that when I rotate it, the feder line bends accordingly. The feeder line is not a perfect curve, and it's not meant to be really. besides I couldn't get the IK splines doing what I want. It was tough enough the way I did it.