(01-23-2018, 05:46 AM)Ken S Wrote: Sharpco,
My first Edge on Up tester is the original KN-100. It is not as fast to use as the PT-50 series, however, I like it. It sits on a user provided postal scale. The knife is held in a clamp. Pressure is applied with BBs or lead shot. For very quick testing, I filled a plastic 35mm film can with enough BBs to weigh exactly 100 grams. I used this as a "go-no go" standard. If the knife edge cut the test media, I knew that the edge was equal or better than 100.
This 100 gram film can is a good way to test your scale. Whenever you get readings which don't seem right, weigh the film can. If it reads 100 grams, your scale is working properly.
With readings in the 260 to 295 range, my first thought would be that you may have some residual burr. Perhaps the test media is moving the thin burr slightly. I would suggest working some more on deburring and retesting. If the tests improve, your tester is not only measuring sharpness, it is a diagnostic tool.
Keep us posted.
Ken
Ken,
This knife is my utility folding knife. I don't sharpen it before testing but a month ago, I honed it with a leather wheel. So it seems burr is not the cause.
After that, I tried testing with a freshly sharpened knife and OLFA cutter. But these also have the same result.