I wanted a version that worked with a real sharpening stone rather than sand paper. I've created all the files from scratch, so parts are not interchangeable with the version by Techtomics that inspired this design.
Print the wedges upside down with the angled face touching the print bed. The wedges are designed to have an interference fit with the "shuttle" which houses the standard ball-bearings. If you have trouble getting the wedges to snap on you'll have to file the inside edge until it does. Try using thinner layers and check that you aren't over-extruding the exterior walls on the subsequent wedges if it is an issue.