After the first flight of your newly built multi-copter, you will immediately want to add a camera. This sequence of events follows the laws of physics and is as predictable as gravity. Just strapping a camera on by way of a fixed bracket may technically solve that problem, but it creates another. A multi-copter tilts and rolls as a result of changing flight direction. If the multi-copter tilts and rolls, so does your camera. This is where a gimbal comes in handy, it adjusts the camera in an equal and opposite direction than that of the aircraft. If the aircraft tilts forward, the gimbal tilts the camera backward the same amount. The result is a steady camera for capturing some sweet videography.
Team SSG over at rcgroups.com has come up with what they are calling the Super Simple Gimbal. Their vision was a gimbal that would be inexpensive, easy to build and add minimal weight to the aircraft. On a normal gimbal, there are two motors or servos, each one specifically controls a single axis of movement. On the SSG, there are 2 servos but they do not move independently from one another. The camera is mounted to a plate that is supported on one end by a piece of silicone tube which becomes a fulcrum for the system. The other side of this plate is supported by 2 linkages (also made of silicone tube) that are themselves connected to the servos. If both servos move up, the camera is tilted down. If the right servo moves up and the left down, the camera is tilted to the left.
So how do the servos know what to do and when to do it? Some multi-rotor flight control boards have outputs for connecting the servos directly. The control board uses the on-board gyroscopes and accelerometers to sense the movement of the aircraft and determine how much to move the camera.
If you are interested in making one of these for yourself head over to the above link to find everything you need. Thanks goes out to Team SSG for documenting this project so well. If a fancy brushless motor gimbal is more your style, check out this one you can print with your 3D Printer.