I took a small gear motor and slightly modified an old auger bit that was laying around. Then welded a couple of pieces of black pipe together and stuck a cam and switch on the end. A 7-up or mountain dew bottle makes a great feed holder. I probably could have made it independent and put it on it's own timer, but I have it running off of my computerized controller that runs the rest of the system. The only think I paid for was the gear motor, which was around $12....plus I lost my $0.05 deposit for ripping the label off the bottle. It works great! NOTHING gets stuck in there and it could easily take off a finger if you stuck in in the feed tube. After all, the bit is made of hardened steel and is designed to drill through wood!
Here it is all up and running. Right now my goldies are small and are still on flakes...and there's some pellets mixed in there.