This is a simple 2 axis gimbal that uses two brushless motors and a AlexMos simpleBGC controller with seperate joystick. The gimbal stabilises roll and pitch of the movement, so the camera stays level. Price for the purchase parts is about $100 total.
In the PDF you find full bill of material, with web links for the vendor parts. On page two are some remarks and instructions.
The STL and native Inventor 2014 files are attached in the ZIP file.