We take our peas to a man who has a sheller. The drum is made of oak with the frame inside of the screen so the frame beats up the pea shells as it turns, there is a beater that turns about twice as fast as the drum and is just oak 1x2s that extend out from the shaft on small angle(think the reel on a small grain header on a combine) the beater boards are about 2" away from the frame work of the screen. One other thing this sheller has a wide belt the width of the sheller that sits on a slant and runs with the top of the belt going up. peas roll down and hull pieces go up and out the back. I know what I said here is not very clear but i hope it helps, if you ask a direct question about a part ect i will try to answer if no one else can do better. Ed