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Post by BastlWastl on Jun 20, 2018 19:17:51 GMT
So you really thing an edge with maybe 20 degree cuts longer, then an edge with maybe 40 degree.... ? Greets Sebastian.
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Post by robin on Jun 20, 2018 19:59:54 GMT
Yea. There's science to back it 🤯🤗
This is... For 99% of sharpeners, there are of course those like you who choose the route of adding microbevel with a loupe/microscope and feel it benefits your style, as a deburring technique. I know we dont agree even what the term sharpening means 🤗 but even in your terms, i think you would agree most every knife out there should be "thinned" in order to cut better and longer.
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Post by Julius on Jun 20, 2018 21:09:09 GMT
Yea. There's science to back it 🤯🤗 This is... For 99% of sharpeners, there are of course those like you who choose the route of adding microbevel with a loupe/microscope and feel it benefits your style, as a deburring technique. I know we dont agree even what the term sharpening means 🤗 but even in your terms, i think you would agree most every knife out there should be "thinned" in order to cut better and longer. But that science doesnt consider chopping boards and real world conditions. The reason that the 20 degree edge cuts the cardboard longer is probably that the thinner edge still cuts even when actually having lost its fine edge due to thinness but it would probably fail at cutting Tomatoes into fine slices, as suntravel has pointed out. Take a thin 20 degree laser and chop wood with it and it will surely be faster blunt than a thick knife with higher angle.
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Post by KAMON Messer on Jun 21, 2018 9:44:00 GMT
Also ganz klar ist der versuchsaufbau unzureichend um KÜCHENMESSER zu testen. Wofür dieser versuchsaufbau taugt ist um optimale schneidwinkel für maschinenmesser zu bestimmen und um die Verschleißbeständigkeit verschiedener Stähle bei gleichem Winkel und dicke miteinander zu vergleichen und selbst das nur bedingt (dazu unten mehr).
Ich finds halt wirklich schlimm, dass hier mit einem halbherzigen und unüberlegten versuchsaufbau "Wissenschaft" betrieben und diese ganz offensichtlich falschen Ergebnisse dann als allgemein gültige Regel für Küchenmesser angepriesen wird. Verbildung auf höchstem Niveau könnte man sagen.
Es wurde von einigen hier ja bereits geschrieben und eigentlich gibt es da garnichts mehr zu diskutieren. Der versuchsaufbau berücksichtigt weder den Aufprall aufs Brett aber was meiner Meinung nach noch viel wichtiger ist - er berücksichtigt die Winkeländerungen die beim schneiden VON HAND auftreten nicht. Ganz im Gegenteil, bei diesem test trifft die Schneide immer mit perfekten 90° aufs schnittgut. Irgendwo logisch, dass eine Flache schneide mit 20° auf diese Art und Weise sehr viel mehr aushält wenn sie keiner querbelastung ausgesetzt ist. Genau das ist aber was eine Flache schneide im praktischen Gebrauch versagen lässt! Was glauben die tester was los ist wenn man im wiegeschnitt übers Brett rauscht? Oder auch beim normalen schneiden... man wird nie mit perfekten 90° ins schnittgut schneiden bzw am Brett Aufprallen und deshalb wirken immer querbelastungen auf die schneide die in diesem test einfach mal so vergessen (??) wurden. Dass bei querbelastungen dann größere Winkel, den kleineren gegenüber, im Vorteil sind ist nur logisch und ich denke nicht, dass man das weiter erklären muss.
Was der richtige Weg wäre um einen Wissenschaftlichen versuchsaufbau für Küchenmesser zu bauen, ist indem man eine kontrollierte Winkeländerungen mit einbaut. Eine leicht oszillierende Bewegung über die längsachse des Messers zb. Auch eine simulierter Aufprall aufs Brett wäre wichtig denn wie viele von euch schneiden ihre Lebensmittel frei in der Hand?
Um zu meinem "dazu unten mehr" zu kommen: wenn man ein Gerät baut, dass den Faktor Mensch mit simuliert, was unabdingbar ist wenn man verwendbare Ergebnisse für Küchenmesser haben will, wird man denke ich auch feststellen, dass Stähle mit vermeintlich schlechter Verschleißbeständigkeit gute Ergebnisse erzielen. Zb wird die schneide eines c70 zwar abrassiv schneller abgetragen als die eines m390, allerdings wird sie sich bei Flachen Winkeln nicht so schnell umlegen oder ausbrechen was sie im Vergleich zum m390 dann bestimmt besser abschneiden lässt als es bei dem jetzigen versuchsaufbau möglich wäre. Auch würde man feststellen was hier in dem forum bis auf Ausnahmen eigentlich eh Konsens ist - nämlich, dass höhere Winkel langsamer verschleißen, sprich länger scharf bleiben.
Lg
Benjamin
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Post by Gabriel on Jun 21, 2018 10:01:06 GMT
Yea. There's science to back it 🤯🤗 This is... For 99% of sharpeners, there are of course those like you who choose the route of adding microbevel with a loupe/microscope and feel it benefits your style, as a deburring technique. I know we dont agree even what the term sharpening means 🤗 but even in your terms, i think you would agree most every knife out there should be "thinned" in order to cut better and longer. But that science doesnt consider chopping boards and real world conditions. The reason that the 20 degree edge cuts the cardboard longer is probably that the thinner edge still cuts even when actually having lost its fine edge due to thinness but it would probably fail at cutting Tomatoes into fine slices... That's exactly the point. The lower the angle the better it still saws due to microchipping at the edge. So robin you are right. The lower angle cuts longer paper with a sawing motion. That's what has been proven by this experiment. That's it. I can't find any comparison for cutting food in a typical cutting technique or on a board
So - of course as it is will all aspects in life... it depens... what are you cutting and how? When you are sawing through paper, obviously a microchipped saw helps.
But as I'm concerned, you're nice knives are not for sawing paper are they?
KAMON Messer I consider myself sort of a scientist... and it always annoys me when some non-scientist consider single experimental results as the one and only truth...
Best Regards, Gabriel
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Post by zetieum on Jun 21, 2018 21:44:52 GMT
Interesting topic and discussion. Few points about the results of this experiement: the authors show that a lower sharpening angle allow to to achive a better cutting capabilites than a obtuse angle, for the same knife thickness using their model. After some cuts, it can be noticed that the low angles loose relatively much more cutting ability than the obtuse angle. Thus low angle loose sharpness faster. But since low angles have a much better cutting capabilities , it still but better than obtuse angles, which loose relatively less. This may explain the feeling that the knife become dulier more quickly Now about scientific aspect. Indeed in this experiment, like in EVERY experiment, the authors used a model. " All models are wrong, but some are useful" In thier model, the authors measure the ability to cut as the the number of cut cards. Is this model representing the truth? NO. Why? simply because perfect models do not exist. A model is a *representation* of a real phenomenon. It mimics reality in conditions that can be controlled in order to minimize the variability of the measurements, and to be able to measure infleunce of changing parameters. Why is this useful? because it is reproducible, because we can argue on it, because we can propose experiement to go further etc. We have data ,results, we disucss the interpretation objectively. It is not a claim like: "I fell my edges last longer" etc. few points about the model model: - the model is more fit for slcing than chopping. Indeed the motion it reproduce is a slice. Never the less, the majority of the cutters, are never pure chopper: the is almost always a slicing movement (like push or pull chop). - The model does not take into account food penetration: As soon as a card is cut, it fells: so not penetration
Now about the results and inerpretation. To my knowledge, it is the only scientifically sounds study I have read one the subject. It is certainly not perfect, but still gives indication that low angle perform better than obtuse one in some cases. I nerver saw the demostration if the reverse.
In conclusion, I cannot resists linking this famous meme:
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Post by satanos on Jun 22, 2018 5:26:13 GMT
Conclusion:
Never trust any statistic which hasn't been faked by yourself.
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Post by KAMON Messer on Jun 22, 2018 5:50:01 GMT
Now about the results and inerpretation. To my knowledge, it is the only scientifically sounds study I have read one the subject. It is certainly not perfect, but still gives indication that low angle perform better than obtuse one in some cases. I nerver saw the demostration if the reverse. You are right by saying that those experimental models never will cover the whole aspects of real life conditions. There are so much reasons for why this isn't possible but almost all involving factor human and the many variables that come with this factor. So there I'm with you. However what I tried to point out is that scientific results should not necessarily give exact real life data, but scalable data which stands in the right proportion to each other so you can make some conclusions to real life conditions. Though this absolutely isn't the case with this setup. This setup doesn't consider essential parameters like the impact on the cutting board and more important in my opinion, the forces acting on the edge from sideways. I think if those forces would be considered in a proper experimental setup the results would turn in the opposite direction and therefore the results from this study may give us some scientific correct results but NOT for the kitchen, or in general Hand held knife application, but more Likely for machine knives. So in my opinion those results are plain wrong making people believe something which in real life behaves exactly the opposite way. I think it's kind of sad when people/scientists put that much effort into a setup and test like this but sabotaging their results by not considering essential factors for those results to be scalable to begin with. Sincerely Benjamin
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Post by suntravel on Jun 22, 2018 6:04:47 GMT
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Post by BastlWastl on Jun 22, 2018 6:59:13 GMT
Kurz mal ausprobiert: Stahl SC125 @ HRC 65..... Also eigentlich der Ideale Stahl für solche Versuche........ Geschärft mit DMT 325`er und Shapton Pro 5k (ideale Tomatenschärfe), Schärfwinkel 10 Grad. Schneide nach dem Schärfen Schneide nach der Zubereitung einer kleinen 2 Personen Pasta......... (2 Zehen Knoblauch und ein bisschen Kräuter kamen noch dazu.....) Das Messer zeigt eine total zerdegelte Schneide, scharf ist es gefühlt noch etwas, aber nur aufgrund von einem teils zerbröseltem, teils umgelegten Grad... Mensch was ist diese "Wissenschaft" toll ..... Ist auf jedenfall eine Top Methode wenn man das schärfen nicht verlernen will, und keinen Wert auf seine Messer legt. Grüße wastl.
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Post by KAMON Messer on Jun 22, 2018 7:03:05 GMT
Und jetzt einen Vergleich mit 36° gesamt bitte BastlWastl. Lg Benjamin
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Post by BastlWastl on Jun 22, 2018 7:05:30 GMT
Und jetzt einen Vergleich mit 36° gesamt bitte BastlWastl. Lg Benjamin Ist gerade in Arbeit! Grüße Wastl.
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Post by BastlWastl on Jun 22, 2018 7:17:52 GMT
Also hier das ganze nochmal, Schneide mittels Shapton Pro 5k mit 17,5Grad repariert und nochmal das gleiche geschnitten ....... Die Interpretation überlasse ich euch . Messer ist im übrigen noch genauso scharf wie nach dem Schärfvorgang. Nach dem reparieren Schliff mit 35 Grad Nach dem schnibbeln.... Den Artikel sollte man in "How to kill your knife within one Minute" umbenennen . Grüße wastl.
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Post by Gabriel on Jun 22, 2018 8:28:10 GMT
Moin,
zetieum okay, in principle, I agree with most of your points. And indeed, I do not know either about any existing more reallife study on this topic. Certainly, becaus e there is no sufficient demand in the market for that... I mean... the EU certainly won't fund a R&D project with the goal to analyse the cutting abilities and edge retention of kitchen knives in near real life conditions
But... as you said:
few points about the model model: - the model is more fit for slcing than chopping. Indeed the motion it reproduce is a slice. Never the less, the majority of the cutters, are never pure chopper: the is almost always a slicing movement (like push or pull chop). - The model does not take into account food penetration: As soon as a card is cut, it fells: so not penetration
...the model is ONLY fit for slicing without contact of a hard surface (e.g. a cutting board). So, if we want to transfer that aspect into the world of kitchen knives, basically the only kitchen knife you could compare that to, would be a Yanagiba. Fair enough.... I mean, I didn't measured the edge angle of my Shigefusa Yanagiba but it is certainly low - very low...
I don't know how you cut with your Gyuto, Nakiri etc. but, IMHO the main load on the edge is the contact on and to the cutting board (bones etc. excluded). So in fact, a study on the influence of the edge angle on an axe for wood chopping would supply a better comparison to (non-Slicing) kitchen knives actually than this one
I just highlighted to IMHO most important aspect of your interpretation.
Another point... just because it's the only study doesn't enhance its scientific value Certainly, I'd have had some criticism if I would have been (I review quite a few papers in material science in the last years) the reviewer of this study...
So what's my conclusion? Of course, what we all already know... it is always best to tune your edge for the cutting purposes you want to use the knife for. If you're handling a only slicer, that will not have board contact... it makes sense to me that a low angle achieve a longer edge retention (due to microchipping effects etc.). But for a "normal" kitchen knife with board contact that you are using in pushcut, chopping or in a rocking motion? I guess it will certainly be a whole different story.
Best Regards, Gabriel
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Post by BastlWastl on Jun 22, 2018 9:52:21 GMT
So zetieum, robin what you think ? Is it better do destroy a knife with low sharpening angle, or cut at least 10 times longer with a higher angle and no really downside ? I just realized that i made a bad mistake ... Maybe the red onion is the cause of the blunt and destroyed edge ....... So this scientific approach is not even close to usefull (for kitchen knife use). Everybody can test this within some minutes, and see the same i did. Btw. i tested the used pressure with 10 degree and 17,5 degree on a carot.... and even this makes no really difference... So 10 degrees is more than stupid, if you use a cutting board that is not made out of air...... Stupid myth busted! Greets Sebastian.
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