VTOL catastrophically unstable on first takeoff

I am part of a newly formed university UAV club in Madison Wisconsin. We are attempting to construct a tilt rotor aircraft using a pixhawk cube and 3D printed parts. During the first test flight the aircraft displayed highly unpredictable characteristics, mainly violently twisting upon takeoff (VIDEO LOGS. Leading up to the first flight, the pixhawk has been setup with quadplane firmware, and the recommended step by step instructions on quadplanes, then tilt-rotors was followed.

My background is in setting up quadcopters using the pixhawk cube, but this tilt rotor business is really throwing me for a loop. I would be ecstatic to hear your opinion on parameters that could be improved, or general VTOL / quadplane advice, given that we are a new organization we are fully winging it (pun intended).

I have a theory as to what could be causing the violent twisting behavior, there is about a centimeter of play in the forward and reverse direction of the tilt mechanism, which our team is working on correcting, do you think this is a contributing factor, the main cause, or a non issue?

Did you figure out the problem?