Landing gear for multicopters, untested

Here's my first 3D design.
I got fedup of trying to build a proper landing gear for my tricopter, as all previous attemps fail miserably.
You can see it in action in this video www.youtube.com/watch?v=5ZbbOCQd7IQ
It was designed for 13mm aluminum booms but I'm still waiting for one of my friends to print it.