Printed Tricopter

On request, here's the current design of my printed Tricopter.

I'm still working out some problems with the current design.
It might have to do mostly with my terrible piloting skills, but the current Tricopter center plate get ripped in pieces much too easy. I never had that much problems with my Quadrocopter design ( http://www.thingiverse.com/thing:4812 ), which seems to be much sturdier.
Of course, the Tricopter design is foldable, which means that the construction is a bit more comple