2020 GEC #19 Little Rattler Thread

I dont disagree with that, but a few weeks is a pretty short life even if he was flipping them open and closed all day.

A good Mechanical Engineer can do a stress run on the spring(s) as designed and predict a life cycle.... Same Engineer can do, or order, a failure analysis on the broken spring(s) to determine design failure, manufacturing errors or operational misuse....
 
Possibly... But I open/close my knives constantly, some of my favorites have been open/closed thousands of times.
I'm very fidgety. :D

I understand John..... and there are knives that probably have 1,000,000 life cycles..... But these didn't, for whatever reason...... For example a pro SLR camera might have 300,000 life cycles in the shutter mechanism while a consumer camera might have 150,000 cycle life expectancy...... The question is what caused the springs to fail......
 
It will be interesting to see GEC's response to this. As I wrote earlier, spring failure is rare-yes it does occur- but to have two break in a very short time from the same run is puzzling. I feel sure GEC will want to address this one.
 
It probably is a bad batch of steel.
How many knives got this flaw we may never know but one guy getting two knives of the same pattern to break is pretty long odds.

I have a Queen Barlow and some older knives with broken back springs and they always broke in closed position not being used.
Does anyone know if his broke while opening?
 
It probably is a bad batch of steel.
How many knives got this flaw we may never know but one guy getting two knives of the same pattern to break is pretty long odds.

I have a Queen Barlow and some older knives with broken back springs and they always broke in closed position not being used.
Does anyone know if his broke while opening?
I revisited the posts on Facebook and he doesn't mention how he discovered they were broken. My guess is that it broke while closed, but I'm not sure. He mentioned that he had only used the knives for small uses tasks like basic food prep. Randy Bell was the guy who showed the different spring tensions on the Rattlers. He is an engineer at GEC and he mentioned that different spring tension is typical on runs of knives. He didn't share any thoughts on potential causes of the springs breaking, however.
 
Food prep with these tiny knives?;) Hope he wasn't using them as a meat mallet to tenderise steaks :D
 
My eyes aren't as good as they once were and I was looking at the video from a mobile device, so not a large picture. I didn't see a break in the backspring I saw the tang-end of the spring lifted from the well. I.e. the pin sheared. Perhaps I just can't see it right. But I thought they looked like pin failure.

EDIT-I went back on a larger screen. I can see the broken spring just in front of the mid-pin on both. Ill be following this to learn a thing or two, myself.....
 
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My calculation shows .2 % failure rate /// 2 out of 100 = 2 % /// 1/10 of that is .2 % unless I have forgotten too much over the years .

Harry

you’re right that a straight calculation of the rate is 0.2 for 2/1000 knives made, but I think Jiki was asking what the probability of getting two failed knives which is the failure rate to the “n”th power, where “n” is the number of failed knives.

In essence it’s L=100*{P^n},
Where:
L is the likelihood in percent
P is the probability of one failed knife occurring in a random sample (1/500)
“n” is the number of times that failure case was observed in a row.

Getting 2 failed knives is significantly less likely than getting one, so that’s why it makes sense that the likelihood is 4 in a million, or 1 in 250,000.
4/1,000,000=(2/1000)*(2/1000)

Thank you for playing along, Harry- if no one cares its no fun. ;)
 
you’re right that a straight calculation of the rate is 0.2 for 2/1000 knives made, but I think Jiki was asking what the probability of getting two failed knives which is the failure rate to the “n”th power, where “n” is the number of failed knives.

In essence it’s L=100*{P^n},
Where:
L is the likelihood in percent
P is the probability of one failed knife occurring in a random sample (1/500)
“n” is the number of times that failure case was observed in a row.

Getting 2 failed knives is significantly less likely than getting one, so that’s why it makes sense that the likelihood is 4 in a million, or 1 in 250,000.
4/1,000,000=(2/1000)*(2/1000)

Thank you for playing along, Harry- if no one cares its no fun. ;)
And none of that factors in the chance of getting 2 GECs from a run period. :rolleyes:. So we are talking a high number regardless of the equation you use. Add in the fact that a broke spring on a brand new knife is also super rare regardless of the manufacturer and we have quite a special occurrence here.
 
we have quite a special occurrence here.

I will be waiting with baited breath to see what comes of that. I’d just guess that the scale of this <3” knife presents some manufacturing challenges; things like accidentally overheating or work-hardening small metal pieces.

It’s very unlikely to get two defective GECs, but the odds are still better than getting struck by lightening, so it’s got my attention.
 
It would be interesting to see a magnified picture of the blade edge. This would eliminate my fear that he somehow forced the blade down into the well far enough to put excessive force on the backspring.
 
It would be interesting to see a magnified picture of the blade edge. This would eliminate my fear that he somehow forced the blade down into the well far enough to put excessive force on the backspring.

Not a bad idea- any idea how he might have done that? I might think of accidently sitting on it, or dropping it and landing on the back of the blade.
 
Not a bad idea- any idea how he might have done that? I might think of accidently sitting on it, or dropping it and landing on the back of the blade.

Not going to speak for him; but sitting on it in the back pocket or if his belly is anywhere near the size of mine I can see it happening in the watch pocket.
 
cpjN2Sh.jpg
 
Does anyone have a picture of the 19 rattler next to a case peanut,and if I dare,ask next to a 25 or 14
 
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