We make them and use them all the time in East Texas.

We use the following.

5') 4" Light gauge PVC (like is used for drain & vent lines)
1) Slip on cap for the top
1) 4" Y
1) 4" Drain grate like you would use for floor drains

This setup will hold about 30# of corn. We put the Y about crotch high off the ground. I'll see if I can dig up some pics. We usually spend less than $10 on each of them.

We still haven't found a good way to keep the coons & squirrels out though.