The video shows how screen can be used as a pre-classification system. By getting all the pieces roughly the same size, you can adjust the airflow and make the separation more precise.
You can make your own, as shown in the video, but you might want to take a look at this set of sieves made for gold panning that fit on top of a 5-gallon bucket. The smallest sizes are way too small for winnowing (but may have other uses around the workshop) but the larger ones are perfect for pre-classifying.
The video shows how screen can be used as a pre-classification system. By getting all the pieces roughly the same size, you can adjust the airflow and make the separation more precise.
You can make your own, as shown in the video, but you might want to take a look at this set of sieves made for gold panning that fit on top of a 5-gallon bucket. The smallest sizes are way too small for winnowing (but may have other uses around the workshop) but the larger ones are perfect for pre-classifying.