YOU TUBE SITES FOR MECHANISMS
https://www.youtube.com/watch?v=ur5WI16f_Rg
https://www.youtube.com/watch?v=HMQ4u9UlPSQ
https://www.youtube.com/watch?v=OvcrjtIB-CM
https://www.youtube.com/user/thang010146/videos
https://www.youtube.com/watch?v=0BtKJJ1z_cQ&pbjreload=10