I recently finished my hexacopter project. Multirotor is mostly built from carbon fiber tubes and sheets.
Here is a link to a 3D model: 3D model on GrabCad
Hexacopter is sized a little less then 550mm and it weights 1550g ready to fly. Frame itself weights 350g.
-NTM prop drive 28-26 1200kv (286W)
-Turnigy plush 25amp
-4s 5Ah nano tech battery
-Crius AIO pro flight controller
-other sensors and stuff
Here is few videos showing how hexacopter was built.