Knifetests.com-whats YOUR opinion

[Broos]

Let's say we have a metal (0170-6C) rectangular bar, uniformly hardened to 58HRC exactly.
Case 1) - Bar width is 30mm, thickness is 4mm and the length is 150mm. Bar is fixed in a vise, let's say at 50mm mark.
Case 2) Exactly same as above, except bar thickness is 4.4mm and length is 200mm.
The nature of the force applied to the bar is the same (i.e. both are impacts, or both are constantly applied), and so is the moment distance.

Now, can you calculate or estimate how much mire force would be needed to break or bend the shorter bar?

For strength, yes - every ME student does similar calculations in their 2nd year. And the steel can't tell whether a person or a machine is applying the load - it will (given no other issues that will cause premature failure) break when the tensile strength of the steel is exceeded. You test for tensile strength with a machine that pulls a standard test specimen apart while measuring and recording tension on the test piece.

For impact tests, you can make a calculation, but test results often have scatter. As I mentioned, there is lots of info on impact testing on the web available for your perusal.

 

[Guyon]

I can't wait for noss4 to unlock the secrets of the universe. I'm giddy with excitement.

 

[Gator97]

For impact tests, you can make a calculation, but test results often have scatter. As I mentioned, there is lots of info on impact testing on the web available for your perusal.

I think you misunderstood my post. I wasn't asking rhetorical question. I really wanted to have the formula here, and do some rough calculations.

It was Wayne G. (who has been testing edge retention by cutting rope for decades), who said it was not very hard to cut a piece of rope straight and doubted lateral forces had much to do with testing edge retention.

As I can see you didn't dismiss his statement right off the bat, because he didn't use any devices to measure lateral forces correct?

 

[Guyon]

Uh oh. I think Gator97 is about to unlock some secrets himself.

Will this open up a worm hole? Will we be swept into another dimension?

Is the Large Hadron Collider involved?

Who will survive and what will be left of them?

 

[Gator97]

I can't wait for noss4 to unlock the secrets of the universe. I'm giddy with excitement.

I think Noss is doing fine as he is, with you promoting knifetests.com in this thread all you can

Uh oh. I think Gator97 is about to unlock some secrets himself.

???

 

[Broos]

I can link you to sites that will explain how you can calculate it if you wish. I'll even offer to check your answer afterwards.

I suspect that if more actually did some vector diagrams & calculations, there would be less disagreement over what can be correctly concluded from these videos.

 

[Gator97]

Well, I was hoping for a formula + short summary form you, that'd be a lot faster, but ok, I'll settle for the links. Thanks!

 

[BladeWarriorTony]

To properly test a knife you don't need to chop concrete or hammer it thru wood. You simply test the knife by using it for what it was designed to be used for.
Probably already been said but I just had to throw in my two pennies.

 

[Broos]

See section under bending stress - I think this is right... You'll need some data from the steel mfg's product testing.

http://www.engineersedge.com/strength_of_materials.htm

Even a calculator out there (you will have to calculate the moment of inertia for the beam).

http://www.efunda.com/formulae/solid_mechanics/beams/casestudy_display.cfm?case=cantilever_endload

 

[Broos]

As I can see you didn't dismiss his statement right off the bat, because he didn't use any devices to measure lateral forces correct?

That is correct - he has developed his feel by doing the testing for 30 years or so, and as far as I know his rankings (or Phil Wilson's) do not differ greatly from those you will get with a CATRA machine.

 

[orthogonal1]

Imitation, they say, is the sincerest form of flattery. orthogonal1, I do appreciate the compliments.

But c'mon. Einstein? TGHM? Are you freakin' kidding me?

Now I will grant one thing. You've already got Hammers of Truth, Swords of Doom, a oddly clad cult figure, and some feats of strength. Throw in a story line or two and some graphic art, and you might have yourself a pretty passable comic book. But genius? No way. The dude can barely spell.

Hardly flattery.

Simply responding to nonsense in the same style it is presented.

Einstein is a reasonable anology. Einstein presented a mathematical proof that then had to be proven in the physical world to be right or wrong.

And, as usual, you lead the discussion off on a tangent.

Have you proven NOSS4's conclusions wrong? No.

 

[theonew]

Despite Guyon's perennial and infantile implication that anyone who doesn't immediately start hurling insults at Noss and these tests, must therefore be a worshiper, I have plenty of problems with these tests, even given the non-scientific basis in which they are conducted. I've been mulling over some ideas to add more repeatability and operate in a semi-destructive manner. Sadly I don't see them being scientific enough to pass muster here and will therefore most likely just draw derision and jeering. So I guess if I end up doing something it won't show up here on Bladeforums. Gotta love the open and free exchange of ideas :thumbup:

 

[Guyon]

Somehow, once again, I missed where orthogonal1 repeated TGHM's "results."

Did I pass out and miss an entire page or something?

Despite Guyon's perennial...

I guess that answers my question. I did pass out. What year is it?

 

[Guyon]

Einstein is a reasonable anology. Einstein presented a mathematical proof that then had to be proven in the physical world to be right or wrong.

So, let me get this straight. noss4 is now a theorist of the highest order?

Fascinating stuff.

 

[orthogonal1]

Somehow, once again, I missed where orthogonal1 repeated TGHM's "results."

Did I pass out and miss an entire page or something?



I guess that answers my question. I did pass out. What year is it?

Somehow, once again, I missed where Guyon proved NOSS4's results incorrect.

As usual, there is much talk of calculating forces, deformation, etc. But as any second year ME student knows, calculated data must be verified with physical testing.

Perhaps Guyon did pass out and dream he did prove NOSS4's conclusion incorrect?


I guess that answers the question. Guyon admits to passing out and not even knowing what year it. But we are still waiting.

 

[Gator97]

To properly test a knife you don't need to chop concrete or hammer it thru wood.

It's not about that, but about letting people do what they want and do their own tests without being policed and bashed here.

 

[Gator97]

I suspect that if more actually did some vector diagrams & calculations, there would be less disagreement over what can be correctly concluded from these videos.

I suspect a lot of it will hard to correlate, and also, your unwillingness to provide/do some of those calculations doesn't help the issue either.

And after his little hissy fit on his video (the one where he did not know how to pronounce broos ), I have every right to call him out.

I have no idea what video are you talking about, but assuming he said something bad about you, and you have there right to call him out. Except based your post, I figure it happened once, the video incident. Comparing your post count, only those including "calling him out" exceeds that very significantly. At some point that does become counterproductive, no? And considering all the bashing he gets here and he's still a kid(according to you)...
If you want to match potential number of the viewers of the said video, that's somewhere 1-2 mil I guess.

 

[Gator97]

So, let me get this straight. noss4 is now a theorist of the highest order?

No, between you and Noss, you are theorist of much higher order(besides being Noss' promoter), and he's a practitioner to the extreme.
Please note, I give you a lot of credit by classifying you as a theorist, since what you mostly do is not even theorizing, but just criticizing based on purely theoretical "correct knife testing ideas".

And once again, we're not saying Noss is Einstein, or a theorist of highest order. We merely point out that bashers and naysayers like you, can, and most often do, easily dismiss/shut up everyone, starting from any n00b, and ending with Einstein, which I quoted from the link provided by you...

 

[Guyon]

It's not about that, but about letting people do what they want and do their own tests without being policed and bashed here.

People can do whatever they like within the legal limits of their jurisdictions. And within the limits of this privately owned forum, they can say what they like. They simply shouldn't come into a community of intelligent folks and try to sell a lawnmower as a Cadillac if they don't want to be called on it. It's really that simple.

 

[Gator97]

People can do whatever they like within the legal limits of their local jurisdictions.

Sigh. You dont' really think that badge icon is real do you? Local jurisdiction as far as this forum goes is not violating, forum rules which btw clearly state that namecalling, personal insults and such are strictly reserved to W&C.

And within the limits of this privately owned forum, they can say what they like. They simply shouldn't come into a community of intelligent folks and try to sell a lawnmower as a Cadillac.

Last time I checked Noss wasn't neither selling anything, nor forcing anyone to take his ratings and test methods for granted.
You & Co. on the other hand, are pushing your beliefs and ideas how one should treat/test his knife, often derailing threads, obstructing whatever that person might do and so on.
As orthogonal said, for now it's your word against Noss' word + his videos. You can't deny, he puts a lot more effort and money in those tests than you do(based on your published reviews)...
On what grounds do I, or anyone else "must" believe your statements that Noss is evil and bad for the community.

You are doing the same thing what Slim did, accusing Noss of what he's never done. Slim's rant about massive fraud from Noss is no better than your "selling lawnmower as a cadillac"... Both are false statements and if anything else, lower the credibility of your statements in general.