I had a friend call me with an issue. When he roasts he finds 1 to 3 unroasted beans. I told him to get a rubber mallet and tap the down chute when starting his roast. That maybe they are getting stuck bellow the hopper. He spoke to another roaster that suggested putting 1.5 lbs of ball bearing in the drum and turn it on. He says that it knocks all the debris free. I told him that I thought that was a bad idea. If he did do this it could damage the paddles in the drum. I also said that if the beans were trapped in the drum they would come out like charcoal when they popped free. Anyone want to chime in on this?