There is no better way to learn 3D printing and electronics than building your own things. RobotGeek has shared a guide that shows you how to build your own 3D printed Arduino Automatic Fish Feeder. You can use it to feed your fish for up to 10 days when on a vacation.
This automatic fish feeder is made using a Geekduino, RobotGeek 180 Degree Robot Servo, sensor shield. Duino mount, and a few other parts.