About this 3D model

My first project here. I´ve done twice and it works well. The idea is keep fixed with 2 bolts. The piece is strong and don´t move ( twist ) when it goes down. Some videos: 1) http://www.youtube.com/watch?v=Fhdpmq-1gPY&feature=youtu.be 2) http://youtu.be/2yfGTHKOF4w I hope you enjoy it.