Loc: Denton County
I made sure that the tubes were high enough so they couldn't do chin ups, then put 4" PVC around the legs, you don't have to fasten them to anything. The coons or squirrels can't grab onto them to climb. I went to BP and measured the height of one on display to see what height to make the tubes.
I had the same problem the last couple of years. Bought 6 dukes dog proof coon traps on eBay. I baited them with marshmallows minis. The first night I caught 6 coons at the same feeder. They never got wise of the traps. I caught a total of 28 last season. I stopped seeing any coons in the cameras at my protein or corn feeder so I moved the traps to different feeders and lost count after that of how many were caught. Had a lot of fun catching them with my kid. It was probably the best approx $70 I have ever spent.