T400 Quadricopter arms v3

News arms for the T400 quadricopter (https://www.thingiverse.com/thing:2896966)

Previous version included motors support wirh screws. Unforunatly, plastic is not suitable for this purpose and motors were moving causing the quad to be unstable.

This version corrects this issue by using standard carbon plates as supports for motors. Now quad is very stable and rigid.

Update v4: bigger motor cable holes and path.