Love this project! Definitely going to build this myself. I'm in the UK. Nice and simple yet very effective. I've actually ripped the video so I can keep it in my collection. The only thing I'd change is with the drawers, don't cut them with a bevel on them but instead, after you've made them use a palm router with a V bit to cut that angle into the top. That way you don't have a gap in the corners.
Umm. Nope. Most of the chaff and some seed get hung up in all these 45° angles. The plywood fibers seem to be creating to much drag. I'm gonna attempt to sand them as smooth as possible. I've even tried making those angles slightly steeper. But, alot of it still gets hung up. I've tried 3 different fans at all sorts of speeds. Made a 2" hole on the end with an adjustable vent opening. I have slid the last slope this, and that way with disheartening results. I still get as much chaff in the seed side as the chaff side. The seed and chaff are super dry and separated. If I hand winnow, the separation of seed to chaff is near perfect.
It looked like a lot of chaff was getting stuck on the ramp or being pulled down into the right bin in the demonstration. But I didn't see any of it in the right bin when they were showed 🤷♂