I see that there are a lot of creative homemade roasters here. I made mine from a tomato can, a free electric barbecue, a thrift shop cordless drill, and a variac won on eBay. It roasts 4 oz of beans per batch and seems to be quite repeatable. I control the timing to first and second crack by adjusting the variac at specific times as indicated on the stop watch. When it is time to cool I pick up the drum by the shaft and blow compressed air through the holes in the drum. The air mixes and levitates the beans, resulting in nearly instantaneous cooling.