Diamond knife sharpener. By HAMMERLAND. 15:09 video:
https://www.youtube.com/watch?v=t5pnXKs5a4s
Previously:
https://www.homemadetools.net/forum/...408#post158386
https://www.homemadetools.net/forum/...475#post154867
https://www.homemadetools.net/forum/...154#post153665
https://www.homemadetools.net/forum/...906#post148713
https://www.homemadetools.net/forum/...374#post116664