Finish changing from ball bearing pivot to bronze washer.

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Alan,
high school physics and science and length of the lever. Right?
I wish life was so simple.
In theory your "knife science" holds the water about those stop pin and pivot and lock distances. By the way, I wonder... how much difference (in Newtons) you get if you calculate the force for your Steel Will knife and some other not so perfectly engineered knife? I bet you can do the math with all your knowledge.

OK, here we have "good" Steel Will knife and this "bad" expensive knife from your example.
Now, put into equation the cross-section of the lock (how thick and wide), length of the lock and material of the lock (what steel), hardness of the lock and how the liner with the lock was made (uniformity of the structure, micro cracks in the material, sharp edges..... etc).
Now calculate or simulate how much force is needed for both those liner locks to "give up".

But this is just a tip of an iceberg.
Now you also need to add dynamic forces to the equation.... if you stab something hard there will be not just static but also dynamic forces.
Then you also need to take into account the stiffnes of the whole knife. The whole knife will deform/bend at the impact and this will also impact forces on the liner lock.
But, we are stil just scratching the surface.

Now, can your "science and physics" understand what I wrote?
 
Andy the Aussie said:
I am most pointedly saying you are wrong on your thoughts about using a blade for self defence. However the renowned scientist Blind Freddy knows that walking a couple of spines together is not scientific or entirely repeatable. Why not have them actually RC tested. That would actually be “science”. To turn this around, you make bold statements about science, physics and engineering on a very cheaply made knife. You have proved little other than a, commendable perhaps, commitment to a cause.
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Well, you have to pull the article, I can't find it with Blind Freddy on knives.

I make bold statement because I actually did what I said. You didn't do anything. Until you show your work, it's all talk. I wait for your article on blind freddy.
 
What did I say I did other than have lots of experience with using knives (for knife tasks , skinning, butchering, making shelters and cooking as some examples). I have cut hides from small reptiles to Cape Buffalo. Throw in more than my fair share of up close experience with what edged weapons do to people I think I have a little clue of what I speak. And if my life is on the line it will be a fixed blade from the likes of Busse, CPK, ESEE, Becker etc that I will choose. But I also have more than a few folders thrown in. My CRK Zaan will probably be the one I grab.

Short of locating the works of the scientists and philosopher Blind Freddy to quote for you I will simply say once again - wracking some spines together answers little. Only you need to be happy with your choices however.
 
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TheOne45 said:
Alan,
high school physics and science and length of the lever. Right?
I wish life was so simple.
In theory your "knife science" holds the water about those stop pin and pivot and lock distances. By the way, I wonder... how much difference (in Newtons) you get if you calculate the force for your Steel Will knife and some other not so perfectly engineered knife? I bet you can do the math with all your knowledge.

OK, here we have "good" Steel Will knife and this "bad" expensive knife from your example.
Now, put into equation the cross-section of the lock (how thick and wide), length of the lock and material of the lock (what steel), hardness of the lock and how the liner with the lock was made (uniformity of the structure, micro cracks in the material, sharp edges..... etc).
Now calculate or simulate how much force is needed for both those liner locks to "give up".

But this is just a tip of an iceberg.
Now you also need to add dynamic forces to the equation.... if you stab something hard there will be not just static but also dynamic forces.
Then you also need to take into account the stiffnes of the whole knife. The whole knife will deform/bend at the impact and this will also impact forces on the liner lock.
But, we are stil just scratching the surface.

Now, can your "science and physics" understand what I wrote?
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Ha ha, I still have question how to exactly calculate because I have to split into vectors in vertical and horizontal directions. I am actually drawing out something and run it by Physics Forums to confirm. I know in general, it's true, but to calculate the exact numbers, I want to run it by the experts.

No, I cannot do exact calculation as I don't know the steel hardness of the liner and all that. All I can say is based on lever, you have a better chance with one that has longer distance from pivot to the liner outer contact given everything is the same. Of cause it the liner is thicker or stiffer, it has advantage over a soft one.

That's the reason I did specify that when I try to bend the liner out towards the opposite side to put more pressure against the blade tank, I can feel it is very stiff. I bend the liner like this ON EVERY ONE OF MY KNIFE. I can tell how hard I push to bend the liner. It is harder than the Steel Will of same thickness. That's is also consistent.

Another thing, because I bend the liner lock, it make it much harder to flip the blade as the detent ball push much harder against the blade, it takes a lot more force to get the ball slide out of the detent hole on the blade. I use diamond drill bit to drill the hole out so the mouth of the hole flare out. It is very obvious which blades steel is harder. Some knives are very easy to open up the hole, NOT THIS CHEAP KNIVES. IT IS HARDER THAN THE STEEL WILL. It might not be scientific, but it's very consistent. I have more than 10 Steel Will knives that I drilled the detent hole, I have a very good feel of how hard to drill the hole.

BTW, Steel Will has consistently show better design than this cheap knife. I just have a lot of it, also Steel Will do not have a 3" knife robust like this one. Their Cutjack is very well design for the weight. The distance from the pivot to the tip of the liner lock contact is 0.54" for the 3.5" blade. It's only 3.7oz for a 3.5" and is very thin.

I have the Warbot, that's a robust knife. the distance is full 0.6" and the liner is about 0.06" thick that's very thick.
 
Andy the Aussie said:
What did I say I did other than have lots of experience with using knives (for knife tasks , skinning, butchering, making shelters and cooking as some examples. I have cut hides from reptiles to Cape buffalo. Through in more than my fair share of up close experience with what edged weapons do to people I think I have a little clue.

Short of locating the works of the scientists and philosopher Blind Freddy to quote for you I will simply say once again - wracking some spines together answers little. Only you need to be happy with your choices however.
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That's not good enough, you came out and quote someone, I could not find it, you cannot give me the prove. we are going nowhere. I cannot agree with you. you still just say " you are wrong" without proof.

This part is not self defense, it is science, I at least show my theory and provide some numbers. I am drawing out the vectors to ask the Physics Forums to get more accurate answer. BUT I CAN ASSURE YOU I AM IN THE BALL PART WHAT I SAID.

It's no point to talk. I am not interested in "you are wrong, but i cannot prove it.". This is a total waste of my and your time.
 
Funny so many people here said I am WRONG. BUT I YET TO SEE ANYONE GIVE ME FACTS THAT I AM WRONG. JUST SAY I AM NOT AN EXPERT, WHAT DO I KNOW.

anyone actually have real reason to prove I am wrong, I am more than happy to listen.
 
Conversely can you prove your whacking of spines (is that where we still are) is accurate, repeatable and consistent? Or just your option based solely using your experience? A question to ponder.
 
So Alan,
I guess you don't understand there is much more then just distances.
Well, I can't say I didn't try.
You know, you remind me of an wind mill... it makes the same sound no matter what wind is blowing.
😉
 
Andy the Aussie said:
If you are defending your life with an edged weapon things have become very very dire. You need a tool that will provide some level of incapacitation. Knives have two functions when being used in a fight, stabbing and slashing (in the broadest of terms). It has been my experience that stabbing (unless one takes out the spinal cord) is somewhat ineffective as often the stabbed does not in fact know they have been so (often I hear "I thought he punched me), stabbing may certainly be fatal but not necessarily quickly so (quick enough to prevent that person doing you serious hard before they bleed out or drown from a leaking lung). Slashing, likewise the assailant *may* not know it has happened however loss of use of a hand/arm because you have severed tendons/ligaments often brings this point home, the psychological impact of "lots of blood" cannot be discounted either. If a blade can't makes it's way through clothing etc and into some mobility/dexterity aiding meaty bits it is not much use. Taking a blunt or easily blunted knife into a knife fight (no matter if there are one or two knives, it is now a knife fight) is akin to taking an unloaded firearm. It may also be the case that if a person defending themselves fails to inflict enough injury on their attacker they just make the bad person angrier from which point onward they press home an attack. Blunt knives make very very poor impact weapons.

I watched CCTV of an incident (working to identify the assailant) in which two guys got into it in the gaming room ("slot machines in US speak) of a pub. Words exchanged and a push and shove then "punches" including a pretty wild looking haymaker than connected with an upper arm. The one struck described the sensation of being struck hard in the arm with something hard. His assailant turned and walked away casually as the victim stood their wondering why his arm was not really responding. His bicep had been split in half down to the bone, lucky not to bleed out and lucky the other guy didn't press the attack (he had in fact previously murdered). There is no half measure especially if age/physical ability is not on your side.
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Interesting stuff, but I am still not completely convinced.

Have you considered the possibility that a sharp knife could cause less pain and initially less obvious damage than a dull one, and that this could be counterproductive in stopping the attacker before they are able to cause you serious harm? The perception that "I thought I just got punched" might have something to do with this. The knife is so sharp that it cuts and pierces too cleanly for someone who is already pumped full of adrenaline to be able to mentally process.

If your goal is to stop an attacker, then causing pain could be more effective than causing serious damage, especially in the absence of a level of pain which corresponds to the seriousness of the injury that was inflicted.

A dull knife can still slice open skin and can still stab. It's just less effective at it... which might actually be preferable if you want to avoid accidental death or permanent loss of function.

I also think that talking about slicing tendons to immobilize a limb, or splitting muscles in half... is a bit... crazy... for the average person. If you know how to do that and you are able to execute it in a fight, then I think you're not a normal guy. But I don't know. Maybe that stuff is easy to learn?
 
alan0354 said:
Theory is very important particular simple and obvious stuff. you don't believe in theory, it's up to you. That's how engineers work.
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I thought engineers build stuff & test it, and theoretical physicists just do the math. The point of testing is to discover any variables not yet accounted for in the theory.

Here's a story: When I was a kid, I used a cheap knife to pry something. The blade bent. Maybe you should bang the spine of your knife against your car door to make sure it's hard enough for the job.
 
alan0354 said:
I just use nedfloss as an example as I have one given by my grandson.

I am not here to earn respect, I talk about my work, I really don't care whether I get respect or not.

Theory is very important particular simple and obvious stuff. you don't believe in theory, it's up to you. That's how engineers work.

I don't want to get into argument, you have your believe, I have mine, we agree to disagree.
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First- it's TANG not "tank". And it's TAB not "tap". And it's PRYING not "plying". Please use proper terms. Not very engineery of you Alan.

Second- it was funny earlier that you asked someone for a link for verification but you've provided no links for verification of your claims, especially regarding things like "better" or "weak" or "poor design".

Third- you don't seem to understand how theory works. Anyone can propose a theory. But then they have to be proven true by demonstration. Something you have failed to do to this point. So it's just more noise from you.

Fourth- just because you like cheap knives with soft steel and poor edge retention and sloppy, poorly fit locks and big clunky overkill hardware doesn't mean everyone else does. I promise you that you are in the tiniest minority imaginable.

Lastly- you keep throwing around terms like "better" "stronger", etc.....that close up pic of the step shoulder stop pin you keep showing is a scathing indictment of the quality and precision craftsmanship of whoever manufactured that atrocity.
 
r8shell said:
I thought engineers build stuff & test it, and theoretical physicists just do the math. The point of testing is to discover any variables not yet accounted for in the theory.

Here's a story: When I was a kid, I used a cheap knife to pry something. The blade bent. Maybe you should bang the spine of your knife against your car door to make sure it's hard enough for the job.
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Banging it against his hard skull might be a more valid test.
 
alan0354 said:
I make bold statement because I actually did what I said. You didn't do anything. Until you show your work, it's all talk. I wait for your article on blind freddy.
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"Hello black pot".
 
After 4 pages of this thread I lost the track what suppose to be the final purpose of all this.
Apparently the starter of this thread wants yet again to impose his theory with very limited knowledge by measuring distances on disassembled knife.
I found the same story on some other forum by coincident when searching Cliff Stamp posts.
Alan, what is the point? What would you like or need?
Ok, you got it. Your distances work. You got the theory and science. You have made yourself survival and prying and self defence knife. Good.
Is there something else you would like to share? Some other science? Anything?
 
Why do you all keep feeding this troll?

Alan is not here to engage in discourse. He is here to troll.

Let’s just ignore him, and he will get bored and go away. And we will lose nothing of value.
 
J. Doyle said:
First- it's TANG not "tank". And it's TAB not "tap". And it's PRYING not "plying". Please use proper terms. Not very engineery of you Alan.

Second- it was funny earlier that you asked someone for a link for verification but you've provided no links for verification of your claims, especially regarding things like "better" or "weak" or "poor design".

Third- you don't seem to understand how theory works. Anyone can propose a theory. But then they have to be proven true by demonstration. Something you have failed to do to this point. So it's just more noise from you.

Fourth- just because you like cheap knives with soft steel and poor edge retention and sloppy, poorly fit locks and big clunky overkill hardware doesn't mean everyone else does. I promise you that you are in the tiniest minority imaginable.

Lastly- you keep throwing around terms like "better" "stronger", etc.....that close up pic of the step shoulder stop pin you keep showing is a scathing indictment of the quality and precision craftsmanship of whoever manufactured that atrocity.
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Hey look the car was only $8. The $13 knife ought to make short work of it if needed. No one is thinking logically here.
 
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