DATF250 250mm mini quadcopter frame

This is my 2nd 250mm quadcopter frame I designed as well as used.

Here's the video
(please start at 0:22)
https://www.youtube.com/watch?v=_PwdFceX2L8

here's the other video on KK2.1 (untuned)
https://www.youtube.com/watch?v=GCFbt4l7LXU