I can imagine that rocket modeling is a real passion for real hobbyists. They keep building and upgrading rockets to reach better results. KoD and Navic have decided to add active rocket guiding system built of Arduino Pro Mini. It is equipped with 2 axis accelerometer that is constantly measured during thrust.
According to accelerometer data 2 microservos adjust fins to keep rocket vertical. Keep in mind that rocket thrust lasts only three seconds – there is quite task to keep rockets center of gravity right above center of pressure. Field tests show pretty positive results that you can see in the video.