Many thanks to fellow grainy Lawrence from Alberta, who sent us photos of the small-scale threshing machine that he built.
I built a round drum like a pac man. This was built with scrap pieces of 1" plywood for the sides. Scrap pieces of 1/4" plywood for the outer curve. Two light hinges I had in a jar from something or other. The inside is lined with diamond pattern round baler belting.
Like any homemade project I was so anxious to finish just to see if it would work that some of the fine work was sacrificed. Next time I would soak the 1/4" outer plywood for longer than three minutes. May crack less when attaching to the round sides.
Pre-drill everything before screwing so the plywood doesn't split.
I then made an axel and attached two pieces of the same baler belt with lots of length to rub on the inside. The axel is scrap closet rod.
I would hope that nobody ever follows this example exactly. There should be at least half a million people who would add bearings on the axel. Another half million would put a pulley and add a motor. Some might figure a way to automatically screen the grain from it, and on and on.
The heavy duty chest closers cost $14 and the baler belt was $50 for about 8'.
I used this to thresh Ethiopian Blue Tinge. Using garden shears I cut only heads into the drum, so no straw.
I'm still looking for a fanning mill, but in the meantime southern Alberta wind is performing some of this task.