making a wind vane feeder

I this idea in my head on making a wind vane feeder. The standard ones for sale are quite expensive and really aren't an option for me but I can see a real advantage to using one. so far I am imagining a 55 gal plastic drum (I can pick those up for about 5$) leaving the bottom intact and cutting the sides to leave approximately 1/2 of a side intact to serve as the vane. with maybe just a bit of the lip still on it to give it some stability.

as far as mounting it goes it would have to be at an angle of course. the only two options I can think of are a post or wide footed base with a bearing of some sort. ( I have no idea where to buy a bearing like that ) or two swivel eye hooks, one attached on bottom one on top with the bottom staked firmly to the ground via a cable or nylon rope and the top tied tightly to a tree branch or something.

so my questions are....

have you used one? do the commercial ones even work? have any of you tried to make one of these? where would I buy a heavy duty bearing? 

The only suggestion I have Leah is for the bearing....

I go to my local Handyman Hardware store and simply tell the guys what I want to do, almost like a challenge and they lead me around the store offering suggestions and discussing mechanics.  Before I know it I have what I need or something even better and I'm out the door.

If you do need a heavy duty bearing they will have it plus good advise if your store is anything like mine.

Not sure if this will help, but my family owned an airport. They made the pivot for the windsock from the wheel bearing of a car(or truck). 

awesome idea! thanks! for some reason it didnt' even occur to me to try and use a salvaged bearing! now I can see bearings all over the place!

Leah,
We've used the bearings from a frontwheel drive car. Pour a concrete pier with bolts positioned to mount the bearing and the lug bolts are used to attach the gate or in your case feeder.
www.tapcointernational.com/store/index.php/default/brakeparts/hub-bearing-513017l.html