About this 3D model

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