I wanted to make an automated thing for my cat, one that actually worked without clogging up, and one that could deliver small amounts of food multiple times during a day.
The motor used for the extruding auger is a 10rpm 12V geared motor which can be found here: http://dealextreme.com/p/high-torque-10rpm-12v-dc-geared-motor-91624?r=23893206
The gear motor inside the bowl is a 60rpm 6V motor that can be found here http://seeedstudio.com/depot/gear-reduction-motor-p12-6v-60rpm-p-236.html?cPath=170_171 but this http://seeedstudio.com/depot/gear-motor-6v-60rpm-dustproof-p-714.html?cPath=170_171 might be better as it is dust proof, but I had a few of the others laying around, might update the thing later to take the dust proof motors instead, if my current breaks down.
Notice, the 10rpm gear motor is VERY strong, and got an hilarious amount of torque. This is both good and bad. It is good because it won’t stop if a pellet is getting caught, instead it will be crushed and the machine continuing to extrude the food. But it is bad because if the cat get’s something stuck in there, it won’t stop either, so be sure to secure it so the cat can’t get anything near the moving parts!