I built my own pellet mill using the dies and rollers from a Chinese mill been making pellets on and off for 4 years. I make mine out of the cleanings and chaff from my grain cleaning business the most of the material comes from sunflowers lots of dust and fine particles and some larger stems. This is the easiest material i have found to pelletize. I have made pellets from grass, paper, corn cobs,etc. I also just purchased a Chinese oil press to press the oil out of the small seeds from cleaning the sunflowers and burn the oil in my tractors then pelletize the meal to burn in my boiler I have done a test run and both products worked great. Nothing better than to take a waste product turn it into 2 different fuel sources. I estimated that this year I will have close to 10 ton of cleaning material to pelletize from just my sunflower crop this year alone.