Ever since the last weekend I have been thinking of a better way to protect the Crazyflie rotors and board whilst combining lightness and resistance. Version 1.6.5 of the frame does offer some crash protection and it has been reinforced from v1.6 as some flie users have pointed out that v1.5 can end up being too flimsy. Although stronger v1.6.5 it is still not the best solution to protect the rotors from ground collisions when the quad is flipped, and several flie owners have already complained that flipped flies crashes may end up with impacted motor bearings.
As a response to this problem I have thought of a combined frame. Early tests show that the concept is viable. Unfortunately I am not going to have a lot of time this weekend to develop the concept fully... stay tooned.