JCN
I don’t think 3" or 4" black iron pipe is going to cut it if your wanting a 15' cantilever. Even with 6" your still going to feel some spring, JMO.
Some of the long time PB members might remember this project I built 6 or 7 years ago. I had a vision of what I wanted and started with 2-80' long I beams and ran with it.
