Corona Traditional Grain Mill
This is an inexpensive but popular grain mill. Hand-crank powered and featuring a 1 Lbs hopper, you can adjust the grinding plates to your desired milling size, fine to course. The mill can be clamped to your table or work surface for stability.
The handle could be removed and the mill powered by a drill or motor, though the design doesn't work well with this those implementations, and the hand crank works fine with this mill.