I'm making an automatic fish feeder. It uses a very low torque, low RPM, low energy motor to turn a paddle wheel. The paddle wheel pushes the food off a ledge and into the tank. I plan to make the paddle wheel using a gear. I also have access to a 3d printer to make the part. The motor is definately something I am going to use since it runs for a month on just a AA and I have it and I am not willing to mess with electronics. THE PROBLEM: Jamming. I am planning to make the paddles very flexible to reduce jamming. I don't want to add vibration motors. What designs/tricks/tactics are used in the industry to prevent jamming? I imagine this is a common problem. I'm not married to the paddle wheel idea, just to the motor I am using. Here's a picture of what I imagine miught happen. http://imgur.com/XlMzUTg Much appreciation for any help!