Wire Edge Prevention

[SteveG]

The test knife is made of ELMAX, HRC 62.
The edge was set at 13 dps on a #1000 CBN, and honed at the edge angle with 5-micron diamonds, followed by 0.5-micron diamonds.
The tip half of the blade was then cleaned of the base burr at a higher angle on felt with 1 micron diamonds, and finished at a higher angle with 0.25 micron diamonds.
This way I got the same blade having clean apex on the tip half, and wire edge on the heel half.

Marked sections on the blade edge, and took the BEFORE sharpness scores in the 3 sections of the tip half and 3 sections of the heel half.
The PT50A sharpness tester average score on the tip half and heel half has a negligible difference of 2 BESS, in other words the sharpness tester cannot detect presence of the wire edge - and as we know, this is typical of hard higher-end steels. Only by wider dispersion of the scores in the heel half one can tell that its apex is not as clean as in the tip half.
I could not take a decent image on my toy microscope, but there is a shiny line along the edge in the heel half that may indicate light dispersion by the wire edge.



For impact I used a 3/4" copper pipe over a linear bearing, the impact assembly weight 153 grams.
Positioned the copper roller perpendicular to the blade.

Rolled the copper roller along the edge 1 cycle only, i.e. once forward and backward, and took sharpness scores AFTER the impact.
The results are encouraging -


Next plan is to test more high-end steels in the similar fashion, and also see if the impact assembly weight can be adjusted not to affect the clean apex at all (if possible at all). Maybe half a rolling cycle, only one roll in one direction, will be adequate.

A regular end user who has any model of the BESS sharpness tester will not need the SET stand, just a simple copper roller of a standard load with a handle of some sort, which is easy to make.

Steve, appreciate your idea and the preliminary testing you've done. We are moving in the right direction with the copper roller.
Thanks mate, Vadim.

Now that's the way a test should be done!  Thanks for doing this, and for the clearly posted results.  That's actually very encouraging.  And not too far from my results; i.e. my average after sharpening was 103, and my average after rolling (and a bunch of other intermediate nonsense) was 144.8.

I guess the good news for me is that my crappy edges probably aren't due to a burr.

Thanks again!