TSProf K02 sharpens knife to BESS 20 edge (record setting)

HeavyHanded said:
My old "Edge Inquisitor 3000" in its final incarnation was able to measure dulling pretty accurately, both pressure and draw cut.

For pressure cut it was accurate to within half a pound of pressure or less (I didn't have a reliable way to add/remove less than that.

For draw cutting it depends on initial edge sharpness, but 10lbs of pressure on a draw cut seemed to work for all reasonably sharp knives. You could go lower, but the knife has to be extremely thin and sharp, and not very important anyway as you're measuring edge degradation, not dulling. Most knives tested can still shave armhair when done.

All testing done with 3/8" Manila

Am rebuilding the clamp and it will back in action in the next couple of weeks.

Anyone has any interest in running some knives on it let me know.




https://www.bladeforums.com/threads...tolon-fine-stone.1535072/page-2#post-17641738

https://www.bladeforums.com/threads...multiple-testers.1328846/page-3#post-15429203

https://www.bladeforums.com/threads/edge-inquisitor-3000-edge-tester.1339015/
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I'd run 3/4 and 20lbs
That would speed it up
 
DeadboxHero said:
I'd run 3/4 and 20lbs
That would speed it up
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Most failed within 200 passes, and were still pretty sharp.
My biggest issue with using 3/4" is that HD and Lowes only carry 3/8" reliably. It also keeps the pressure cutting loads pretty reasonable.

The biggest advantage is that it measures both draw and pressure on the same widget.
 
HeavyHanded said:
Most failed within 200 passes, and were still pretty sharp.
My biggest issue with using 3/4" is that HD and Lowes only carry 3/8" reliably. It also keeps the pressure cutting loads pretty reasonable.

The biggest advantage is that it measures both draw and pressure on the same widget.
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I've been doing 3/4 Manilla start at 5lbs and stop at 20lbs. Seems to really speed up the testing with most knives stopping at 20-40 cuts and crazy steels going +100 cuts
 
DeadboxHero said:
I've been doing 3/4 Manilla start at 5lbs and stop at 20lbs. Seems to really speed up the testing with most knives stopping at 20-40 cuts and crazy steels going +100 cuts
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Can you factor pressure cutting?

I ultimately made my testing widget as I had zero confidence in my ability to pull accurate numbers with any human factor. The only variable I have to control is draw speed, and it doesn't seem to matter a whole lot as long as you aren't going super slow or very fast.

And then the rope is always a little variable, I go to 3 consecutive fails. And then is a good idea to run the test twice. If
the numbers are within 15% or so they go into the average. For pressure cutting it is a good bit more consistent.

This is the original incarnation, I don't have any picks of the current rig:
 
Let's talk in your thread about it.



HeavyHanded said:
Can you factor pressure cutting?

I ultimately made my testing widget as I had zero confidence in my ability to pull accurate numbers with any human factor. The only variable I have to control is draw speed, and it doesn't seem to matter a whole lot as long as you aren't going super slow or very fast.

And then the rope is always a little variable, I go to 3 consecutive fails. And then is a good idea to run the test twice. If
the numbers are within 15% or so they go into the average. For pressure cutting it is a good bit more consistent.

This is the original incarnation, I don't have any picks of the current rig:
Click to expand...
 
It would be interesting to see cut tests with everything equal (same knife, geometry, etc) except for starting BESS scores (20, 50, 100, 150, 200, etc) to see how much difference the starting sharpness makes, compared to how long an edge will hold to a fixed dullness.

It might also be of use doing the same thing with only the abrasives being varied.
 
jpm2 said:
It might also be of use doing the same thing with only the abrasives being varied.
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I noticed a couple of trends I'd be surprised weren't also seen in the BESS scores. One was using AlumOx abrasives on high carbide steel (Norton Watersone) my best #s improved after switching to SiC wet dry, and on high Vanadium the best #s were produced using diamond abrasives. Using relatively coarse (Norton Crystalon) on high RC/high VC steel produces an edge finish considerably more refined than the same abrasive on regular steels - making it a strong contender despite how it should perform on paper. Keeping in mind they all "felt" sharp informally - crosscutting paper, shaving armhair cleanly.

The other thing I noticed was up to a point when the draw cutting #s improved due to coarse edge finish (and they did), the pressure cut poundage went up. A really refined edge for pressure cutting could still perform good/great draw cutting but it wouldn't last as many cycles - verifying many anecdotal reports.

I left off before I could triangulate best overall edge finish for draw retention and low initial lbs for a pressure cut, but strongly suspect it will be in the 800-1200 ANSI range depending on the steel - using 3/8" Manila...
 
I think in microns so I looked up 800-1200 ANSI in microns. It's 7.7-3.8 on the two charts I found.
 
HeavyHanded said:
I noticed a couple of trends I'd be surprised weren't also seen in the BESS scores. One was using AlumOx abrasives on high carbide steel (Norton Watersone) my best #s improved after switching to SiC wet dry, and on high Vanadium the best #s were produced using diamond abrasives. Using relatively coarse (Norton Crystalon) on high RC/high VC steel produces an edge finish considerably more refined than the same abrasive on regular steels - making it a strong contender despite how it should perform on paper. Keeping in mind they all "felt" sharp informally - crosscutting paper, shaving armhair cleanly. ...
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I've noticed the same thing, not through any testing, but using the same knife, same geometry, sharpened to seemingly the same level of sharpness with different abrasives, doing the same tasks hundreds of times over the years.

I do believe hardness and carbide content of the steel has an effect on the finish, for a given abrasive.

I've often wondered how using the same finishing abrasive for the whole range of knife steels affects the outcome of some of these cut tests. I've heard it said if the abrasive is bigger than the carbide size, it doesn't matter, but not sure I completely agree. Although agree it's progressively less relevant as the size of the abrasive increases, I'm pretty sure even a larger abrasive is capable of cutting a smaller carbide, that is if the abrasive is harder than the carbide to start with.... and then there's the refinement differences.

The other thing I noticed was up to a point when the draw cutting #s improved due to coarse edge finish (and they did), the pressure cut poundage went up. A really refined edge for pressure cutting could still perform good/great draw cutting but it wouldn't last as many cycles - verifying many anecdotal reports.

I left off before I could triangulate best overall edge finish for draw retention and low initial lbs for a pressure cut, but strongly suspect it will be in the 800-1200 ANSI range depending on the steel - using 3/8" Manila...
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Not sure how my Eze-Lap diamond plates measure in ANSI, but I like to finish with their fine to super fine plates, listed as 600 and 1200 grit. For straight push cutting, I use the little DMT EEF.

I see so many recommendations for ceramic sharpening abrasives when the steel in question is s**v, k390, maxamet, etc, then see comments that say they can't tell any difference in regular steels and so-called super steels.... makes me go, hmmmm...

Anyway, thanks for the reply.
 
TSPROF is neat, but you don't need it to set the record. Skill not tools

Good job Roman.

Nitrobe77 is some amazing stuff at high hardness :D
 
KKnives_Switzerland said:
Yeah, when I just touch a hair with an edge like the one in the video, one part just seems to get "disintigrated" from the rest of the hair and falls straight down. No jump, no pop, just falls like a stone. I like to call that "spooky sharp", haha.
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I'm surprised you can reach that level with a 30 degree angle, not counting the diamond stropping on top of that. Did you finish with stropping on clean leather? That lubrication of the bevel usually boosts to the HHT performance.

It makes me wonder what the BESS fishing line test is actually measuring. There are actually 3 stages to severing the fishing line, penetrating the surface, cutting part way through and finally stretching and breaking the last of the line. It's not obvious to me which of these requires the greatest force. A thinner blade will have an easier time with the second stage, but a thicker blade an easier time with the final stage.
 
ToddS said:
I'm surprised you can reach that level with a 30 degree angle, not counting the diamond stropping on top of that. Did you finish with stropping on clean leather? That lubrication of the bevel usually boosts to the HHT performance.

It makes me wonder what the BESS fishing line test is actually measuring. There are actually 3 stages to severing the fishing line, penetrating the surface, cutting part way through and finally stretching and breaking the last of the line. It's not obvious to me which of these requires the greatest force. A thinner blade will have an easier time with the second stage, but a thicker blade an easier time with the final stage.
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Very interesting thought! Maybe slow motion would reveal more... And I finished on 0.25micron roo leather. Usually I go lower for even higher sharpness - but for the knives I make and sell 0.25 or 0.125 micron does it. I hope to find the time soon to test one of my progressions down to 0.025 micron. Also at a lower angle than 30 inclusive.
 
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