I made some out of 8" duct pipe and rivets. I didnt make them quite big enough around though. I didn't realize how fat these meaties were! Gonna make some bigger ones today. You can get a piece of 8' x 60" duct pipe at Lowes for 10 bucks. You can make 4 or 5 cones out of one stick. Alot cheaper to make your own.
Can you post a picture of the flat pattern?