I built a 3d printed micro octocopter more than 2 years back, when there isn’t really any brushed FC for more than a quad configuration. These days toy grade, quality multicopters came readily available, I decided to build one with more than 4 props.
Recently bought a FC for Eachine X6, from banggood.com, with 3d printed polyamide frame(Taulman bridge) on my heavily modified Ultimaker(200W aluminum heated bed-capable of heating hotter than 150’C, fully enclosed passively heated chamber., dual fan, dual extruder, actively cooled stepper motors, larger power supply and etc). Polyamide is rather flexible thus it is unbreakable and will survive in numerous crashes.
I mixed using used and new motors and since they are brushed micro, used motors provide less power than the new ones causing drifting and yaw. New 7×20 motors and hubsan x4 props(proved most efficient) from banggood is on the way and I am hoping to get better lift and battery life.
Total weight with FPV gears but the battery weighs 53.9g.