Quick and easy tri build using cheap readily available materials. KK2 board, Plush ESCs (stock firmware), Turnigy 2822/14 1450kV motors. I don't cover KK2 setup in this video. Check out David Windestal's videos for tri build and yaw tilt mechanism - http://rcexplorer.se/projects/2011/09/the-tricopter-v2-5/
and KK2 setup - http://rcexplorer.se/blog/2014/12/kk2-setup-video-for-the-tricopter-v3/
Tricopter blog posts - http://newtonairlines.blogspot.com/search/label/-%20tricopter