This is a video of Youtuber How To Make Everything constructing the sawmill detailed in Leonardo Da Vinci’s notebook in 1478, using only tools and methods that existed back then (read: no power tools, makes his own nails). He does use a water pump to replicate a river though to turn the water wheel. Damn, did that say 1478? That was a long time ago! Like 545 years ago if you’re reading this in 2023. If you’re reading this in the future, well, it’s nice to think humanity launched a copy of this website into space before the earth was destroyed.
Thanks to my dad, who agrees it might have been easier to hire some medieval bridge trolls to cut your logs for you.