---

How much coffee do you need to roast at at a time?

It sounds like you will be using an open flame of sorts, so the design will center around that. The illustration Koffee Kosmo provided above could certainly work out. For a drum, you can always use one or two of those large tin cans for Green Beans or Peaches - the very large, industrial sized cans. Two of them would be ideal, you can put them together to make one larger, long drum.

The drum will need at least two (or up to 4?) vanes to stir the beans as the drum rotates, and a shaft through the center.

You can hand-crank the shaft.

Are there any Bar-B-Que grills around? A charcoal grill? This would be a good container for heat, with a lid, and easy enough to mount the drum.

Loading and unloading the beans may be the most difficult to engineer. The drum can have a hole cut in the side, near an end. this hole can be covered by part of a 3rd tin can, or the lid of one of the two you're already using.

CHAD