Tailstock quill lock. By Mateusz Turek. 15:50 video:
https://www.youtube.com/watch?v=ez4UiHxkWGg
Previously:
https://www.homemadetools.net/forum/...855#post167661
https://www.homemadetools.net/forum/...548#post166701
https://www.homemadetools.net/forum/...978#post153059
