Jaw rock crusher. By Donn DIY. 18:28 video:
https://www.youtube.com/watch?v=xlCAIdfvXKI
Previously:
https://www.homemadetools.net/forum/...604#post182338
https://www.homemadetools.net/forum/...424#post162035
https://www.homemadetools.net/forum/...132#post161005