Help grinding beans? I want flour, not sand!

[Guest guest]

I recently bought the grinding attachment for my KitchenAid stand

mixer. Following their instructions, when I grind beans (or anything

for that matter), it comes out more like sand than like flour. I'm

afraid to tighten the adjustment any tighter because I don't want

ground metal in the food.

Does anyone know how to actually get powder instead of tiny grains

from the grinder? Do I just need a different mill? If you have one

that works, please let me know!

For that matter, I'd be happy to buy the bean flours and not grind

myself, but I haven't found anyplace that GF-dedicated mills. Do you?

Thanks!