This is a mini 250 foldable tricopter dedicated for fpv. Video: http://vimeo.com/105471252 Parts are available on Shapeways here RCGroups thread If you feel generous enough, you're welcome to make a donation. Yaw mechanic is protected between the center plate, the whole rear arm turn itself. ( http://youtu.be/u28iwAkf9TA ) 2 camera configuration possible: You'll need small ESC, there's not much space on this little beast. Kiss esc are perfect for that. Here's a video of the yaw mechanics: Most parts are printed with 0.2mm resolution. Motor mounts & arm mounts needs supports. I print the Yaw_arm_horn.stl with 0.1mm, it's better, but not necessary. You can also print the center plates it works good, but it's better to cut them with cnc using G10 or Carbon. You'll also needs: Add a bit of tape on the end of the tubes to give some friction on the motor mounts and front arm mounts. This is quiet sufficient to fix them and will prevent breaking some parts in case of crash ( mounts will turn absorbing a bit of the shock ).