Circular saw blade sharpening jig. By J-woodworking. 8:03 video:
https://www.youtube.com/watch?v=1qPHoSrMe9s
Previously:
51 Best Homemade Woodworking Tools eBook
https://www.homemadetools.net/forum/...709#post174702
https://www.homemadetools.net/forum/...944#post171646
https://www.homemadetools.net/forum/...625#post170489
https://www.homemadetools.net/forum/...882#post167746
https://www.homemadetools.net/forum/...596#post155378
https://www.homemadetools.net/forum/...726#post139978
https://www.homemadetools.net/forum/...057#post120382
https://www.homemadetools.net/forum/...0714#post73000