I haven't done it, but I've also been wanting to grind my own flour, from corn as well as broom corn. I've made oat flour from rolled oats. But I am also looking for a grinder. Just cannot afford the price of a new one though.
try asking on your local craigslist and freecycles. That is what I did and had a lady that was nice enough to GIVE me a working antique corn sheller. It needed to be put on a stand, I screwed it to a saw horse. It works great, and is just what I was looking for. I use it to shell whole corn for my chickens. Good luck!