Here it is, my version of a brushless gimbal. With the addition of a brushless gimbal to your multi-rotor you can turn any run of the mill quadcopter into a professional aerial photography platform. By canceling out even the smallest attitude changes the gimbal can give truly remarkable results. This gimbal is designed around my quadcopter and will also be compatable with my tricopter in the near future.
Update 3/27/15: I have updated the motor mounts to a more "universal" format and I have added extra support on the batter tray to keep it from sagging from the camera and motor weight.
Update 2/17/14: I've added a 1/8th offset to the case, this should center up the lens on the longitudinal axis of the quadcopter, thanks Pylo.
Update 11/14/13: Just uploaded a video I shot of some BASE jumping. Check it out if you are wondering about a gimbal.
Update 01/27/14: Uploaded modified gimbal flies. Added a GoPro3 case as well as well as lock nuts in the arm for easier attachment (thanks Miguel for the idea).
Print and assemble the gimbal. 10% Infill is more than enough as the gimbal does not need to be incredibly strong. The gimbal uses T-motor 2208 brushless motors and a SimpleBGC by AlexMos.
The software, firmware, instructions and GUI can be found at http://www.basecamelectronics.com