umnum test from poland

[GigOne]

Good thoughts - follow the dots...? Does this lead you to question whether using the ceramic ball is appropriate and/or better than the traditional RIL approach?

I thoroughly enjoy when makers employ new developments. If we stick to the same technology, where would we be?

To be honest, at this time, I can't answer your question, as I've only had the knife for a year and a half. I will say, none of my CRK wares have failed me, in the past 12 years, through intended use.

I give little creditability to certain so-called "tests" performed by armatures, as the item is rarely broken down and all parts thoroughly inspected (i.e., damage, abnormalities, etc. of all the parts making up the knife) after each iteration. In other words, material and failure analysis isn't employed and documented (i.e., the use of microscopy, nondestructive testing, metallographic testing, hardness testing, etc.).

I will say, I was impressed with the tire cutting and mud bath iterations. Frig stabbing? Reminds me of something I was told years ago, "Never use the head of a socket wrench as a hammer." Go figure.

 

[JNewell]

I thoroughly enjoy when makers employ new developments. If we stick to the same technology, where would we be?

To be honest, at this time, I can't answer your question, as I've only had the knife for a year and a half. I will say, none of my CRK wares have failed me, in the past 12 years, through intended use.

I give little creditability to certain so-called "tests" performed by armatures, as the item is rarely broken down and all parts thoroughly inspected (i.e., damage, abnormalities, etc. of all the parts making up the knife) after each iteration. In other words, material and failure analysis isn't employed and documented (i.e., the use of microscopy, nondestructive testing, metallographic testing, hardness testing, etc.).

I will say, I was impressed with the tire cutting and mud bath iterations. Frig stabbing? Reminds me of something I was told years ago, "Never use the head of a socket wrench as a hammer." Go figure.

Flint???

I guess the questions are (among others), is the ceramic ball stronger? more durable?

I was similarly impressed by both the mud and tire episodes. I expected to see a fold-up during the tire test, to be honest.

 

[mathu]

I would be curious to know when the deep galling was first noticed. If we follow the sequence of the vids and pictures, it would appear it developed during kamilpoi’s exercise in stabbing the refrigerator, keeping in mind he’s introduced numerous shock loads. Pushing the blade forward, to remove the knife from the refrigerator, is also another key factor. Where is the bearing surface or critical area during each stabbing and blade removal? Tang and ceramic ball. The primary task of a knife is for cutting. Anytime a shock load (as in this case, all steps involved in the repeated stabbing to the refrigerator and removing the blade from the object) is applied, the probably of damage or malfunction increases.

OK, so please tell my why the Mini Socom with a standard liner lock passed all of this with absolute no wear off on the lock? This was the principal assumption of this test - that a little knife without framelock, ceramic balls or other "improvements" can handle stabbing the refrigerator, cutting nails etc. I can show you video where Mini Socom is stabbed into the thick power supply unit and after a few minutes on the sharpmaker it shaves the hair and the only marks of the test are some scratches on the blade. Diabelek, the tester, made all of this with his own knives and he never intended to destroy them - because he was sure that they perform well in such conditions.

So, when CRK stated that the Umnumzaan is going to be beefed up, tactical version of the Sebenza, you should expect that it will be at least as durable as the Mini Socom. Unfortunately it is not. But the worst thing is, it performs even worse that the original Seb. You can stab the Sebenza into the refrigerator and it won't fail. So what's the point in designing improvements that actually perform worse? And again - why test the Umnumzaan by dropping it in the mud? Because the original Sebenza can handle it.

You can argue if some of these tests are abusing or not, but keep in mind that none of them made any malfunctions to the Sebenza. So if the Umnumzaan is advertised as the beefed up version of it, shouldn't it behave at least as good as the Sebenza? This test showed that this assumption is wrong. The ceramic ball may be more durable than the titanium, but the whole lock is actually less durable and it is going to fail while doing extreme work that the original framelock can handle well.

 

[JNewell]

Is the Sebenza test on the same website? I looked through the index of tests and didn't see it. Thanks

OK, so please tell my why the Mini Socom with a standard liner lock passed all of this with absolute no wear off on the lock? This was the principal assumption of this test - that a little knife without framelock, ceramic balls or other "improvements" can handle stabbing the refrigerator, cutting nails etc. I can show you video where Mini Socom is stabbed into the thick power supply unit and after a few minutes on the sharpmaker it shaves the hair and the only marks of the test are some scratches on the blade. Diabelek, the tester, made all of this with his own knives and he never intended to destroy them - because he was sure that they perform well in such conditions.

So, when CRK stated that the Umnumzaan is going to be beefed up, tactical version of the Sebenza, you should expect that it will be at least as durable as the Mini Socom. Unfortunately it is not. But the worst thing is, it performs even worse that the original Seb. You can stab the Sebenza into the refrigerator and it won't fail. So what's the point in designing improvements that actually perform worse? And again - why test the Umnumzaan by dropping it in the mud? Because the original Sebenza can handle it.

You can argue if some of these tests are abusing or not, but keep in mind that none of them made any malfunctions to the Sebenza. So if the Umnumzaan is advertised as the beefed up version of it, shouldn't it behave at least as good as the Sebenza? This test showed that this assumption is wrong. The ceramic ball may be more durable than the titanium, but the whole lock is actually less durable and it is going to fail while doing extreme work that the original framelock can handle well.

 

[BobP63]

Is the Sebenza test on the same website? I looked through the index of tests and didn't see it. Thanks

I couldn't find it either; then I did a Google search for similar Sebenza tests and came up short again.

 

[JNewell]

Parenthetically, it's too bad the online translators don't work better for Polish/English. I've been impressed by how well they work these days for German/English (I sometimes read the Messer forums).

 

[Shing]

Its no surprise that the much harder ceramic ball will wear the softer steel blade. I am surprised that CRK would use it to hold the blade open. The point of using the ceramic ball is the low resistance when opening and closing the blade. To use it to hold the blade open, which uses a combination of friction and force from the lock bar is really not a good idea because the friction will be a lot lower than steel against titanium as well as less contact area.

I think CRK should change the ceramic ball for a harden 440C steel ball which would be about the same hardness as the blade.

 

[xzhang]

IMHO, the point is whether these dents were caused by the force.
i would like to demonstrate the hardness difference between steels and ceramic materials to show you how easy a dent can form on the surface.
The steel used is ZDP-189 with a hardness of 67. The force was ~ 15lb - i did not press hard at all.
Interestingly, after I pressed twice with a spyderco ceramic rod, two dents formed on the steel.
The results here have only shown that under a given pressure, a ceramic rod can leave dents on a steel. I am still waiting for other people's test.

 

[misterjuiceman]

is the ceramic ball on the umnumzaan any harder than the carbide coating that some makers (Tom Mayo, Rick Hinderer,...) use on the lockbar face of their knives? it seems also that the rolling in of the ball will minimize wear.

 

[xzhang]

the use of the ceramic ball minimizes wear; but also it decreases the force of sliding friction, which is important to prevent a lock failure like this.

 

[GigOne]

So, when CRK stated that the Umnumzaan is going to be beefed up, tactical version of the Sebenza, you should expect that it will be at least as durable as the Mini Socom.

Please provide proof of the highlighted portion of your statement.

Here’s a link the CRK, relaying information about the Umnumzaan: http://www.chrisreeve.com/umnumzaan.htm

I can tell you one thing, Chris Reeve and or CRK NEVER, EVER relayed, in any form, that the Umnumzaan was “tactical” anything. I believe I can go out on a limb and state that Chris Reeve goes out of his way not to associate his folding knives with the word “tactical.”

By the way, the term “tactical” is subjective.

But the worst thing is, it performs even worse that the original Seb. You can stab the Sebenza into the refrigerator and it won't fail.

If your evidence of superiority is based solely on stabbing a frig. . . .you’ve failed in convincing me.

It seems to me a number of “tests” were performed and the Umnumzaan did rather well, except the frig stabbing. I have yet to experience a situation where I needed to stab a refrigerator. Of course, YMMV.

I also haven’t seen the need to pry my house, using any knife, from its foundation. Rest assured, I know all of my knives will fail miserably with said task, and I don't need to perform the task to prove it.

So what's the point in designing improvements that actually perform worse?

I'm sure CRK, when designing the Umnumzaan, didn't sit around the designing table with the intention of coming up with an improvement that was intentionally bad or failed.

You have yet to provide credible evidence show the knife performed "worse."

Under normal use, my Umnumzaan has performed flawlessly and as intended. So have my Sebbies. Based on the "so-called testing," shown in this thread, of the Umnumzaan. . . .I highly doubt I'll be giving it up.

And again - why test the Umnumzaan by dropping it in the mud? Because the original Sebenza can handle it.

First, the Umnumzaan has a new type pivot. Second, the mud test is more representative of what would occur in “real life,” while stabbing a refrigerator isn’t.

You can argue if some of these tests are abusing or not, but keep in mind that none of them made any malfunctions to the Sebenza. So if the Umnumzaan is advertised as the beefed up version of it, shouldn't it behave at least as good as the Sebenza? This test showed that this assumption is wrong. The ceramic ball may be more durable than the titanium, but the whole lock is actually less durable and it is going to fail while doing extreme work that the original framelock can handle well.

I don’t see where your conclusion is substantiated by the “so-called testing.” You and or the “tester” somehow established that stabbing a refrigerator as acceptable use of a knife.

The question needs to be asked of CRK.

 

[Biginboca]

There is so much armchair quarterbacking going on in this thread it's hillarious. Do all you quarterbacks questioning the integrity of this design think that Mr. Reeve doesn't test his knives much more exhaustively than anything someone out in cyberland can dream up?

I would love to know the engineering, materials analysis, and other credentials of the knife experts posting in this thread and suggesting thier design changes that would improve the Umnum. It was voted knife of the year by real industry experts for the technology and innovation of the design. But here on the forum it really seems that behind a keyboard everyone is an expert at whatever they want to be!

 

[xzhang]

There is so much armchair quarterbacking going on in this thread it's hillarious. Do all you quarterbacks questioning the integrity of this design think that Mr. Reeve doesn't test his knives much more exhaustively than anything someone out in cyberland can dream up?

I would love to know the engineering, materials analysis, and other credentials of the knife experts posting in this thread and suggesting thier design changes that would improve the Umnum. It was voted knife of the year by real industry experts for the technology and innovation of the design. But here on the forum it really seems that behind a keyboard everyone is an expert at whatever they want to be!

the test has shown how robust the knife is, no one is questioning that. on the basis of the results in the videos and pics, the only question is what caused the lock failure. It is natural for people who support CRK to discuss it, no mater they are experts or not. i believe Mr. Reeve has done enough tests on umnum, but what if there is a flaw in the ceramic ball design? CRK did decrease the number of the ball from 3 to 1. Don't you think it is reasonable to expect the desgin to be better？ No design is perfect. As Shing said before, maybe change the ceramic ball for a harden 440C steel ball will be a solution.

 

[Biginboca]

the test has shown how robust the knife is, no one is questioning that. on the basis of the results in the videos and pics, the only question is what caused the lock failure. It is natural for people who support CRK to discuss it, no mater they are experts or not. i believe Mr. Reeve has done enough tests on umnum, but what if there is a flaw in the ceramic ball design? CRK did decrease the number of the ball from 3 to 1. Don't you think it is reasonable to expect the desgin to be better？ No design is perfect. As Shing said before, maybe change the ceramic ball for a harden 440C steel ball will be a solution.

Here is what I think. You have a sample size of exactly one knife and the keyboard commando knife experts have now concluded that based on the sample size of exactly ONE knife that now the Mini SOCOM is a more reliable design. What foolishness! I have experienced many, many mini-socom lock failures first hand from a sample size of thousands. I for sure would trust the Umnumzaan over the Mini-SOCOM for anything I need of a knife.

Then add the silliness with the refridgerator. I have never had a reason or need to assault a refridgerator!

Basicly I think that when you have tested maybe 50 knives of each then you can draw some useful conclusions. And thinking you are going to make the Umnumzaan better with a 440c ball is ridiculous, IMO.

 

[xzhang]

I do not agree with the comparison at all;
refridgerators are innocent lol;
we have seen only one example, but so far I have not seen any official explanation. I don't want to jump to any conclusion and I didn't;
using a 440c ball is Shing's suggestion, he's a knifemaker, in my opinion, he is an expert.

 

[TLR]

Here is what I think. You have a sample size of exactly one knife and the keyboard commando knife experts have now concluded that based on the sample size of exactly ONE knife that now the Mini SOCOM is a more reliable design. What foolishness! I have experienced many, many mini-socom lock failures first hand from a sample size of thousands. I for sure would trust the Umnumzaan over the Mini-SOCOM for anything I need of a knife.

Then add the silliness with the refridgerator. I have never had a reason or need to assault a refridgerator!

Basicly I think that when you have tested maybe 50 knives of each then you can draw some useful conclusions. And thinking you are going to make the Umnumzaan better with a 440c ball is ridiculous, IMO.

I agree with you that nothing definitive can be concluded from the little we know about this particular knife or the umnumzaan line as a whole. It would be foolish to think so. With that said I'm still intrigued with what happened and what is normal with an umnumzaan lock. I wholeheartedly agree with gigone in that I'm glad makers try new things. Partially because it gives me the opportunity to see how things work and what happens in different scenarios.

I have an umnumzaan on the way as we speak and can't wait to get it. I fully trust that Chris Reeves has forgotten more about knifemaking and how different knife locks work then I will ever know. I expect no issues from it and will use it as an edc.

I personally don't feel qualified in advising how to fix any of these perceived problems as I still don't know if anything is inherently wrong. I certainly am interested however in finding out what happened and what is normal and abnormal with this new lock interface.

My interests are nothing more or less and I see nothing wrong with that.

 

[Foxj]

Well what i wonder is if the blade stop/thumb studs might have dented into the Ti a little bit and cause an alignment issue...AKA making the angle of the blade tang wrong and cause the lock to slip?.....not saying i know just an idea

 

[bigmark408]

I do not agree with the comparison at all;
refridgerators are innocent lol;
we have seen only one example, but so far I have not seen any official explanation. I don't want to jump to any conclusion and I didn't;
using a 440c ball is Shing's suggestion, he's a knifemaker, in my opinion, he is an expert.

I have found this thread nothing short of pure entertainment...i was thinking the exact thing that biginboca posted...Credentials ?

I'm sure CRK is waiting for his zaan to be re engineered in this thread before he makes the final changes

BTW, i have seen many blades with divots (wear) on the lock face from direct contact with titanium also.

Oh yah, i think biginboca has a little experiance with Microtech

 

[Shing]

It dosen't matter how much testing, how well designed and how well made it is and the reputation of the maker, the fact is the lock failed and what needs to be done is find out the strength of the lock.

Stabbing a fridge is not the issue, its the forces that are generated when the fridge was stabbed. If these forces were were low, then the issue of how strong the lock is and how much force and in what direction will cause it to fail.

 

[GigOne]

we have seen only one example, but so far I have not seen any official explanation.

I think it would be hard for CRK to offer an explanation based on a hand full of pictures and vids.

It dosen't matter how much testing, how well designed and how well made it is and the reputation of the maker, the fact is the lock failed and what needs to be done is find out the strength of the lock.

I disagree with the first part of your statement. While some form of conclusive analysis will not identify every possible usage scenario, it has the ability to do what you think should be done - find out the strength of the lock - as well as saving time and money.

Knee jerking based on a lone, poorly documented "test" performed by an amateur can be a rather expensive proposition. I'm sure CRK tracks reported issues with their knives and reacts accordingly.

You're a knifemaker. How concerned would you be if I took one of your knives and induced a failure? For example, by pounding the blade spine with a 10 lb sledge hammer, in an attempt to see if the blade edge would slice through a 2" piece of heat treated stainless steel?