Instead of using all the elbows, and such, to construct the feeders, I just took a 6' section of 4" pvc and cut a 90 degree angle into the bottom and jammed it into the ground so there is about a one inch opening for the corn to escape. Then used two ratchet starps to secure it to the tree. I have found that the three points of contact limit the bears from tearing the setup down, as oppossed to having a feeder just strapped to the tree.
A few other tips:
-stay away from waterholes, tons of birds take a lot of the feed
-use buck jam ( or similar product) at the base, this makes it easier to transition from corn to mineral
-if bears start hitting the setup, move; they will take over