DJI Inspire1 and Walkera inspired quadcopter

In this design the landing gear is driven by a 12 kg/cm servo. There is also a sonar placed looking down for automatic landing or other purposes you may find interesting. If you have suggestions on the design, please comment and I can adapt it to your idea. For the moment I am stuck with ideas on this design and I will start another soon.
I made it so everything can be printed without support and still obtain decent quality.
The main body should be printed with at least 30% infill in order to be strong enough.
Edit1: I added the motor support and the landing leg. The bar between the legs is a fiberglass rod and is meant to flex.