Has anyone done this? We buy coffee beans in bulk and grind enough for 3 or 4 days at a time in our burr grinder. Well, the grinder died and I was thinking, "I have this huge grinder in the garage". I was trying to find information on how commercial coffee sellers grind their coffee in bulk and found the commercial roller mills they use in online searches. The specs seem to indicate that for filter coffee, the setting is 500 - 1,000 um (0.019 to 0.039 in.). I don't know how the configuration of the grooves/studs differ between a grain mill and commercial coffee mill are (how well it would grab and pull the coffee through), but I was thinking it might be a possibility.