Yes I did build a prototype that worked on air. Had all air logic to move brushes and feeders, all you needed was a low pressure air compressor. It never looked like much but it did work pretty good. Only part I never completely finished was the drying section which was basically going to be a hair dryer. You could stack a bunch of chips in one end and they would roll out clean at the other. Here is a picture of the unit (again this was just a prototype I made in my steel fabricating shop):