Recently we made another attempt at splitting and de-hulling organic soybeans since we heard from quite a few people that they cannot easily obtain already de-hulled soybean halves. This was experimental and the picture on the right shows our final solution with a 100 rpm motor (1/10th HP).
We soaked the beans for 24 hrs.
We covered a 1 gall can with a layer of cement to get a rough surface and made a channel with some aluminum for the beans to get squeezed on the way down when the wheel turns (counterclockwise). The distance at the top is about 2 beans, at the bottom half a bean.
This setup worked quite well. 
Getting rid of the hulls is a challenge. We tried several experimental set ups but are trying to keep it simple. The wire basket works the best. Dipping it into the water several times and shaking it brings the hulls to the top. It was possible to shake the hulls to the left side and then dip the basket under the water a little and jerk it to the right. That removed most of them when done a few times. The remaining ones can be caught with a strainer when the beans are in the cooking pot . The hulls come up to the surface just before the water begins to boil.
