Cliff stamp micro bevel

[HeavyHanded]

I agree with the first part. For the later, he used easy to understand (simple) statistics and chart to deduced 2.5 degrees micro-bevel separating edge retention between vg10 and s30v, for very specific case of cutting 1/2" hemp rope. Stated about apex and behind thicknesses + hemp rope type + perhaps cutting style + other variables and testing parameters are not useful as having some comprehensive (and my favorite hand-waving) physics to explain 'what; why and how', especially how one could reasonable extrapolate to different setups. e.g. instead of 1/2" hemp rope, what if 1/2" dia rod of ruber/pine/oak/lead/aluminum/etc..

It would be nice/useful to have some sort of edge retention function where you can plug in steel attributes, geometry, fracturing operations, force vectors/angles => voila spit out a cutting bevel & edge refinement/grit or recommend a # range for missing parameter. Right, ideally we want is a 75+% of good solution/#. LOL - I like to tackle this fun project. LOL too bad, if not for life's monkey wrench, perhaps other might already done so (or maybe already did but I don't about )

I've thought about this and one would almost have to begin with a catalog of common materials one might cut.

Characteristics of how those materials are constructed and speculation re best means of severing with least amount of applied force (draw, press, combination of both expressed in distance and pressure) - along with baseline testing to generate such speculation. This part might not need to be too exhaustive as one could use the same two or three tools with differing geometries and apply several edge finishes per test. Assuming a trend is evident, one might plug in variables based on performance to extrapolate for differing geometries not included in the test. A multiplier could be used based on known wear resistance for a given steel, but maybe only for certain finishes? How one might factor in for lateral stresses is another mystery but maybe as easy as giving a tensile elongation value.

If you could get a rudimentary model up and running, it could be used to predict some performance aspects. How often it deviated from actual results when tested would determine its utility. Is possible (and I believe this would be born out) that those strategies capable of severing at the lowest applied force would also yield the greatest edge retention per task - assuming no failure from lateral stresses.

Maybe when the kids are all grown I'll try to tackle it....

 

[Cynic2701]

Here they are these are pretty low angles from cynic. He posted about a year ago on mirror edges. These are beautiful. Not sure the angles though.

Hi Sharpnessis, thanks for keeping me in mind.

These were done with a 10 degrees per side (20 inclusive) bevel with a ~15 degree per side microbevel (30 inclusive) which were measured by angle cube (for the bevel setting) and then rough estimation for the microbevel.

After some thought, I'm quite certain that the bevels are actually lower than 10 degrees per side. Since I zero the Edge Pro angle measurement with the angle cube without a knife on the ramp and I don't raise the angle from the face of a flat grind when sharpening - in other words half of the angle of the primary grind - I should really subtract that difference in angle from the bevel measurement.

Provided that my thinking is correct, I likely have bevels on the order of ~7.5 degrees per side or 15 inclusive.

 

[Cynic2701]

On the subject of testing, lower edge angles and a microbevel have a long history with Japanese kitchen knives. Global did an interesting CATRA test of whetstone sharpening vs. factory sharpening, and they note huge improvements in edge retention and sharpness on knives that are sharpened by waterstone (i.e. by someone who presumably knows that they are doing) vs. the factory edge.

While they don't provide much information about what edge angles were on the factory knife vs. the waterstone sharpened knife, I'd hazard a guess that whomever sharpened the knives on waterstones thinned behind the edge:

http://global-knife.com/catra/