[Robovergne] wrote in to share his fantastic automated cat feeder with us. After researching the common commercial products he could find, he decided to build one that utilized a home made linear actuator to pull a certain amount out of a reservoir. Initially, he attempted to use microwave motors but ultimately found them to be too weak to force the bits of cat food should they get stuck. He was afraid this extra strain would cause motor failure before too long. Ultimately, he replaced the microwave motor with a fairly strong servo that seems to do the job just fine. He’s currently using an Arduino to time it all, but he does mention that he feels it is a waste of the arduino for such a simple task.
As you can see in the videos after the break, his mechanism seems quite solid. There isn’t a lot of play in the movement and the amount of food coming out seems to be fairly controllable.