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altelis
May 22, 2009, 7:16 PM
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Rudmin wrote: altelis wrote: You say you understand the failure mode, but keep bringing back the point of an unknown history. LEAVE IT ALONE. YOU ARE WRONG. As I and many, many, others have stated the specifics of how the cam failed make its history IRRELEVANT. The cams history, post-leaving the factor, could in no way, shape, or form have affected the test. Just not possible. The failure was at the braze, meaning that the weakest point of the cam was its braze. I said it once, so I will say it again: Did you look at the picture? There was clearly more braze on the outer strands which broke than on the inner strands of the cable that pulled out. Those outer strands were already frayed and broken from use. So the outside cables that were solidly brazed snapped and the inside cables that weren't solidly brazed pulled out. If those outside cables had not been already broken, they very well may have taken the load and increased the strength of the cam. That is how this cams history could have affected its strength.
Ok, that is interesting. I missed this (sorry).
I don't have enough training/knowledge to accurately asses this, so if people wouldn't mind pointing out whats right or what wrong with this statement, I would really appreciate it....
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adatesman
May 22, 2009, 7:17 PM
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retr2327
May 22, 2009, 7:19 PM
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"I was just arguing that I think it is coincidental the one bootied cam that makes it into Aric's hands ("some dude in Pennsylvania with a pull tester") for a test breaks in this fashion. "
It's less of a coincidence than it appears. Aric is not testing good, functional Aliens to failure; he's only testing them to about 1/3 rated strength, IIRC. After all, these things cost a lot of money, and he's not getting paid to do this. And this one might have passed that test too, it seem, or come close.
But BECAUSE it was a manky cam that no-one would want to use, he tested it to failure. And guess what, it failed long before it should have, and for reasons that I think have been convincingly shown to be unrelated to its manky condition.
So the result is a bit of a fortunate accident, but it's by no means as much of a coincidence as it might appear. On the contrary, the fact that this cam failed due to bad brazing really does suggest that if Aric was randomly testing other, non-manky cams to failure, they might fail prematurely as well. And that is cause for concern.
One other point: the idea that this was somehow a reject that made it out into the real world is about the worst possible defense of CCH imaginable. If, for some reason, they had reason to reject this cam, they should have destroyed it. Letting it out onto the market as a second, somehow, or leaving it behind as part of some half-assed test (!!!) would be criminal.
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kennoyce
May 22, 2009, 7:20 PM
Post #279 of 747
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What is right is that if the 3 wires in the cable were not broken, the cam would have held more (I'd guess maybe 1kN more) but would not have held its full strength due to the lacking brazing material.
Once again the strength of the cam isn't really relevant to this thread, only the lack of QC that allowed an incorrectly brazed cam to leave the factory for any reason.
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IsayAutumn
May 22, 2009, 7:24 PM
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Thanks for your response. It makes sense. Anyway, my previous assertion that there is room for doubt have been renounced and I have been cleansed of my sins. But I wasn't trying to get behind any one theory. I was just trying to assert that there was room for doubt, no matter what the cause.
Anyway, as I said very early on in this thread, I would be willing to donate money to see some non-manky cams tested. This is interesting to me.
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roy_hinkley_jr
May 22, 2009, 7:25 PM
Post #281 of 747
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the_climber wrote: There was incomplete brazing, therefore only a portion of the cable is bonded to the head of the cam. There were a few broken strands on the cable. These were far fewer in number than those not properly bonded by the poor brazing job.
This is where you and Aric are wrong. The previous photos showed that the braze was all around the perimeter and missing in the center. Had the perimeter remained intact, the load would be evenly distributed and the unit tests at full strength. It probably would have tested stronger with a proper full braze and a few cut strands but still not as much as you seem to think.
Aric charged this thread by choosing an inflammatory and misleading title. Nice troll! You should get it up to 10 pages at least. Next time try busting some old BD gear (you WILL be shocked at their issues) and picking an equally accusational title.
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altelis
May 22, 2009, 7:28 PM
Post #282 of 747
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kennoyce wrote: What is right is that if the 3 wires in the cable were not broken, the cam would have held more (I'd guess maybe 1kN more) but would not have held its full strength due to the lacking brazing material. Once again the strength of the cam isn't really relevant to this thread, only the lack of QC that allowed an incorrectly brazed cam to leave the factory for any reason.
Thats kinda how I see it too. That at the end of the day, sure, the cam may have had small things happen to it that effect the breaking strength. None of these things would have effected the braze. Even if it wasn't the braze that failed, it was still a bad braze. The braze is a critical part providing strength to the cam. This indicates a QC problem. A QC problem on any one aspect of manufacturing calls the entire manufacturing process into question. We should make sure that we know for a fact our aliens can hold the forces we expect them to.
I think this is really what he root of the problem is, and the heart of the logical progression to get there. While the details are interesting, they aren't really the main concern.
That being said, it seems to me that the issue of greatest concern isn't really an issue that is lab-approprate, eh? That said, you don't want it somewhere where the issue is going to turn in poo-flinging (it is getting close). Any way to split the convo, or at least end the QC portion of the debate here and start another, well-moderated thread?
And I do say well-moderated and not heavily-moderated for a reason. Aric, as much as I am behind you, I think you (understandably) felt your work was being threatened and had a personal reaction. I might suggest that for threads you start in the Lab there may be a bit of conflict of interest with you moderating them. I think these threads should be moderated more than others, but not to too great of an extent. And when you put yourself on the line as much as you did on this one (for which I really do thank you and aren't saying in a bad way) perhaps somebody else could step in do help with the modding duties....
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kennoyce
May 22, 2009, 7:32 PM
Post #283 of 747
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In reply to: the load would be evenly distributed and the unit tests at full strength.
This is where you are wrong, If the three wires weren't broken, yes it would have held more, but no, it would not have tested at or near full strength.
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Rudmin
May 22, 2009, 7:33 PM
Post #284 of 747
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adatesman wrote: Rudmin wrote: altelis wrote: You say you understand the failure mode, but keep bringing back the point of an unknown history. LEAVE IT ALONE. YOU ARE WRONG. As I and many, many, others have stated the specifics of how the cam failed make its history IRRELEVANT. The cams history, post-leaving the factor, could in no way, shape, or form have affected the test. Just not possible. The failure was at the braze, meaning that the weakest point of the cam was its braze. I said it once, so I will say it again: Did you look at the picture? There was clearly more braze on the outer strands which broke than on the inner strands of the cable that pulled out. Those outer strands were already frayed and broken from use. So the outside cables that were solidly brazed snapped and the inside cables that weren't solidly brazed pulled out. If those outside cables had not been already broken, they very well may have taken the load and increased the strength of the cam. That is how this cams history could have affected its strength. Rudmin, In a properly done braze those inner strands would have been completely covered in and bonded to the braze material. This is where the joint derives its strength from and if its not there, the joint will be weak regardless of the condition of the outer strands.
But this is in the realm of speculation now. The braze could be stronger, but the cam might have been strong enough to match it's rating if the outer strands hadn't all broken.
Looking as closely at your pictures as possible, I count roughly 20 wires that were solidly brazed into the cam and snapped versus approximately 16 wires near the core that pulled out. Those snapped outer wires were the ones which would take the most abuse from hard use.
I am not sure how the load would be distributed normally, but it would seem to me that the outer strands would have to take most of the load anyways, even with a full inner braze, because they are held against the side of the hole by the brazing. The inner strands can only be brazed onto the outer strands or attached to the bottom of the hole by their tips. The braiding of the wire would then distribute the load ore evenly further down the wire.
Of course this is all speculation, but my point is that there is a whole lot of assumptions being made here/
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adatesman
May 22, 2009, 7:43 PM
Post #285 of 747
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kennoyce
May 22, 2009, 7:44 PM
Post #286 of 747
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In reply to: I am not sure how the load would be distributed normally, but it would seem to me that the outer strands would have to take most of the load anyways, even with a full inner braze, because they are held against the side of the hole by the brazing. The inner strands can only be brazed onto the outer strands or attached to the bottom of the hole by their tips. The braiding of the wire would then distribute the load ore evenly further down the wire.
When brazed correctly, every strand of the cable will help share the load within the cable because brazing essentially makes the cable into one piece instead of individual wires. The interface between the cable and the cable eye will be the point where the braze is transferring the load from the cable to the cable eye, but this isn't where the failure occurred.
As for the braiding of the wire, this wouldn't have helped much due to the fact that the cable was 7x7 so the center bundle of 7 wires would still be relatively free to pull out due to the lack of brazing material bonding it to the outer 6 bundles.
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Rudmin
May 22, 2009, 7:52 PM
Post #287 of 747
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adatesman wrote: Go down to the local tech school and learn a bit about brazing before you post again. You'll look a lot less stupid. Any braze that is not completely filled is an improper braze, will not engage all of the strands of the cable and will fail well under spec. End of story. .
That is assuming that the cable is designed to be the weakest link in the system and that the cable is expected to fail just above spec with a perfect braze.
Is it impossible for the cable to be specified to be strong enough to meet its strength rating even with a partial braze?
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jt512
May 22, 2009, 7:53 PM
Post #288 of 747
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adatesman wrote: ATTENTION- I RETRACT MY EARLIER CLAIM THAT SOGDIANA=NADIA@CCH There was a miscommunication between myself and another user which resulted in the IP confirmation. I took what he said to mean that he had gotten an email from Sogdiana, when in fact he had gotten an email from Nadia. The IP address for Sogdiana's posts here on RC looks to have gone through a proxy of some sort (not uncommon) and is the same as a bunch of other users here on RC and is not the same as that of the emails I got from Nadia. I will go through the thread and hide all posts relating to this and deeply apologize for the misunderstanding. -aric.
Whatever. They're still the same person.
Jay
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adatesman
May 22, 2009, 7:55 PM
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adatesman
May 22, 2009, 7:58 PM
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retr2327
May 22, 2009, 8:02 PM
Post #291 of 747
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"you buy a new set of Aliens, black through red (above that most folks don't use anyway, and no need to make you spend more than that). Aric pulls them to failure."
Well, before we destroy a (possibly) perfectly good set of Aliens, let's note the difference between pull testing to their rated strength, versus pull testing to failure. It would seem that if they reach rated strength, that's good enough; no need to keep going.
Then the question becomes, does such testing cause any form of latent damage?
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jt512
May 22, 2009, 8:06 PM
Post #292 of 747
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Tipton wrote: wolfdog wrote: Old gear out in circulation found to have defects. and that is worthy of posting a defamatory post becasue...? I thought your whole issue was with MANUFACTURING DEFECTS. My whole point is that you can prove nothing by testing used gear of unknown origin and you are somehow trying to sidestep the issue. All your tests are invalid because you are using gear of unknown origin and history, THATS MY POINT DUDE! Man up, test some new Aliens and see what happens, add some validity to your testing. You man up, take my bet, and we'll test some new Aliens. Or don't. We know what would have happened anyway, and I'd be happy with my new cams.
If he takes the bet, he'll probably win it. I no longer trust Aliens, but I doubt that they're so unreliable that in a random sample of only 5, you'd find a bad one.
Jay
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k.l.k
May 22, 2009, 8:10 PM
Post #293 of 747
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adatesman wrote: Tell you guys what... I've got a couple hours to kill before my wife gets back from DC and there's an EMS with Aliens about an hour away. If you Paypal me the money (or make other arrangements, as my wife will kill me if I fund this test) I'll go pick 5 and break them tonight/tomorrow. Other people have expressed an interest in seeing new ones break so they may even chip in. Gotta warn you, my money's on more than one failing under spec.
Why waste the dough? The results won't matter to anyone. We already have plenty of data, both about the habits of Aliens in the wild, the manufacturing process, and CCH's customer service and dedication to the community.
No matter the outcome, folks who believe in Aliens will continue to do so, just as those who believe the earth is less than 10,000 years or that the CIA carried out the 9/11 bombings or that Elvis is alive and living with Headhunters in Borneo will continue to believe as they do.
It is a shame, but you can't force someone to professionalize. I suppose at some point, CCH will probably be forced out of business, but then conspiracy theorists will blame everyone involved in the "Alien testing hoax."
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roy_hinkley_jr
May 22, 2009, 8:13 PM
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adatesman wrote: In a word, no. A brazed wire rope connection can be up to 95-100% the strength rating of the wire rope, but that assumes a properly executed joint with proper flux, temperature, filler, etc. And seeing as the size wire rope spec'd for the stem you're needing the entirety of the wire rope's rated strength.
Sorry Aric, you're pulling stuff out of your butt here. You clearly don't understand the mechanism of failure when the system is compromised. This isn't stuff you're going to find in a text book since they deal with. Please do some more research. Breaking a couple of cams really means nothing.
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kennoyce
May 22, 2009, 8:16 PM
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I'd be happy to donate $10 or so if enough people want to join.
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k.l.k
May 22, 2009, 8:18 PM
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roy_hinkley_jr wrote: Breaking a couple of cams really means nothing.
That would be true if there were no other context. But this particular, fairly minor episode belongs to a much bigger history.
And all the engineering issues aside, the way that CCH has handled this episode is telling. Of course, their response also fits their historical pattern. As we all know, other manufacturers respond very differently to questions about failures or quality control.
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jt512
May 22, 2009, 8:21 PM
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IsayAutumn wrote: CCH hasn't responded, and I can't speak for them as to why. But my point is, nobody decked on this thing, and it's origin is unknown.
It's origin is CCH, and it has a defective braze. End of story. The pull test isn't actually relevant.
The problem seems to be, at least partly, that CCH is using a manufacturing process requiring a great deal of skill and which is essentially unverifiable. If you use their gear, you just have to trust that the dude who did the braze wasn't having a bad day. Given the number of reported failures over the past few years, this trust isn't warranted.
Jay
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kennoyce
May 22, 2009, 8:22 PM
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In reply to: Sorry Aric, you're pulling stuff out of your butt here. You clearly don't understand the mechanism of failure when the system is compromised. This isn't stuff you're going to find in a text book since they deal with. Please do some more research. Breaking a couple of cams really means nothing.
I really don't see anything being pulled out of Aric's butt. Everything looks very reasonable to me. It might help me believe you if you had any kind of credentials, I know Aric's but there is nothing on you. It might also help if you added any reasonable knowledge on the subject rather than just stating that it is wrong.
I'm confused on why this stuff can't be found in a text book, oh there I see it, its because they deal with.
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adatesman
May 22, 2009, 8:29 PM
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cracklover
May 22, 2009, 8:33 PM
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adatesman wrote: cracklover wrote: Yeah, if Aric's not up for it, deal's off. Otherwise my deal is - you buy a new set of Aliens, black through red (above that most folks don't use anyway, and no need to make you spend more than that). Aric pulls them to failure. If any fail under their rated strength, I buy you either a set of Metolius MasterCams or BD C3s in the same size range as the black through red Aliens. If they match their specs, you buy me a new set of black through red aliens. Only you can't go selecting for the ones that look shoddy! Gotta be fair about this. GO Tell you guys what... I've got a couple hours to kill before my wife gets back from DC and there's an EMS with Aliens about an hour away. If you Paypal me the money (or make other arrangements, as my wife will kill me if I fund this test) I'll go pick 5 and break them tonight/tomorrow. Other people have expressed an interest in seeing new ones break so they may even chip in. Gotta warn you, my money's on more than one failing under spec.
I haven't heard back from Wolfie, but if he's out of the bet, I'd chip in a few bucks anyway, just for you to break some more Aliens.
But I'm with Jay. I'd guess that of Aliens made today, maybe one in five hundred is bad. Absolutely horrible by any manufacturing standard, but that's damn good odds for me to win my bet.
GO
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