Update: Added a version with M6 Hex Screw insert so push a M6x8 machine screw with 9.8mm wide hex screw head. Break the edges of the print to ease the insert. The screw itself should be approx. 7-8mm long in the thread. This setup fixes the problem of the printed thread breaking off within the sharpener threaded insert.

This plate screws into the Horl sharpener main body. Use double sided tape to stick sand paper to it. Do not overtighten, you do not want to break off the thread inside. Will definetely not beat the original diamond grinds, but its a good compromise for heavy sharpening jobs like regrinding a whole old machete. Happy sharpening :)