Chip, the cones on my trap are about 12 inch dia on the large end and about 5 inches on small end, they are perhaps 16 inches long. I just took a piece of netting about 2 feet wide and long enough to make this size cone and rolled it up into a funnel and wired it. Then I trimmed each end square so that the hole is round rather than the resulting odd angle with an odd shaped hole that you get when you roll a rectangle into a cone. Good luck. It's fun to make your own stuff once in a while. I know you can buy something similar (aquaticeco.com) but I get a kick out of figuring out how to make it myself.
