The above is good advice. Rice would be an ideal and cheap grain to use. I have a motorized Phil Mill I and IMO, it's very highly underrated. I particularly value the ability to adjust it on the fly. This eliminates the need for feeler gages and is much easier than stopping the mill, loosening set screws, turning eccentric bushings, tightening the set screws, checking the gap, checking the grist and repeating the whole procedure if necessary. Most with other mills just say screw it and leave their mills at the same setting for everything. Unfortunately, I've heard that the Phil Mills are no longer in production and that's a shame.