Hydraulic harrow. By Mateusz Doniec. 13:40 video:
https://www.youtube.com/watch?v=WyRPVVZbVcQ
Previously:
https://www.homemadetools.net/forum/...788#post167419
https://www.homemadetools.net/forum/...604#post166900
https://www.homemadetools.net/forum/...535#post166663
https://www.homemadetools.net/forum/...305#post165746
https://www.homemadetools.net/forum/...286#post165681