Want to make a Bicycle Grain Mill

Or blow up because of the heat involved. flour powders beats a lot for explosive potential. Thats why mills traditionally run in the day, because a candle flame would blow them to kingdom come.

 

The Weather_dot_com app has a video of a collapsing corn silo. It has a flash explosion due to the corn dust hitting a power line. Impressive.
Sugar, especially powdered sugar, can become rather "energetic" too.

 

Something about a layer of salt on every third layer of bundled hay in the loft, is ringing in my subconscious! Perhaps it's OJT from day's gone bye?????????

 

Coffee grinder can go anywhere from course to just about powder. It just doesn't do a lot at one time.