|
|
|
|
cracklover
Mar 9, 2009, 9:45 PM
Post #151 of 177
(10854 views)
Shortcut
Registered: Nov 14, 2002
Posts: 10162
|
Evanwish, the trouble is that your "point" (essentially that sometimes one cam might hold while another might not) is essentially meaningless. It's kind of a statistical no-brainer.
But to make matters worse, there is a *real* issue that your point kind of glosses over. The issue is this - to some people, the OP Link Cam is seen as the "go to piece". The piece for blind placements. The piece where you can assume that it is likely to hold where many other pieces may fail. While for other folks, it is seen as a "specialty piece". One that requires more care and sophistication to place. That has a narrower range of usable options, even while it has a wider camming range.
And no-one really knows which of these perceptions is more accurate or more reasonable. All we do know is that tests with funky conclusions like that of the OP in this thread only muddy the waters, making it hard to know which one of these viewpoints has more validity.
GO
|
|
|
|
|
jt512
Mar 9, 2009, 9:45 PM
Post #152 of 177
(10853 views)
Shortcut
Registered: Apr 12, 2001
Posts: 21904
|
kachoong wrote: d0nk3yk0n9 wrote: evanwish wrote: justinboening wrote: evanwish wrote: jt512 wrote: evanwish wrote: it seems untill we find a placement where the link cam holds and the camalot doesn't, the score is BD=1, OP=0Another victim of American education. Jay haa and how's that? all i'm trying to get at is that for that one particular place for one cam worked over anther. so there's bound to be a placement that ties it up ps: if there isn't i guess we could conclude that link cams suck for other than perfect placements i guess (which i highly doubt) It can't be the SAME placement. That's the issue. There are just far too many variables. You just don't get it, evanwish. no i get the fact that it can neve be the exact place because of head width etc, if you read above i said as close as possible. yes there are a ton of variables, but all i'm trying to get at is that in that specific section of crack, the link cam wasn't the best cam for the job. i doubt USnavy was intentionally putting the link cam in a worse position than the C4. The key is (and this is what the guys who've been debating this point with you are trying to say) that the variables that mean that it isn't the same placement could mean that the link cam was in a worse enough placement then the C4 to make a different in the results. [image]http://fc91.deviantart.com/fs6/i/2005/064/c/0/Beating_A_Dead_Horse_by_livius.gif[/image] Or more clearly, you can have both cams in what you think is exactly the same place and yet gain different results mainly due to factors that you cannot see. This type of "experiment" is so hard to replicate!
I don't think that it would be too difficult to replicate the experiment, but you do actually have to have replications. Two groups of N=1 doesn't tell you anything about differences between brands of cam. Try two groups of, say, N=100; then compare failure rates.
Jay
|
|
|
|
|
pmyche
Mar 9, 2009, 10:25 PM
Post #153 of 177
(10827 views)
Shortcut
Registered: Jan 21, 2004
Posts: 1160
|
|
|
|
|
|
michaellane
Mar 9, 2009, 10:48 PM
Post #154 of 177
(10816 views)
Shortcut
Registered: Feb 16, 2004
Posts: 89
|
pmyche wrote: Thanks to Michael from Omega Pacific for promptly responding.
Yer welcome ...
Navy ... if you're interested in having us look at your cam, the offer still stands. Give us a call for a Return Authorization and we'll confirm whether it was damaged in the fall or not.
--Lane
_____________________
Michael Lane
Omega Pacific
800.360.3990
|
|
|
|
|
USnavy
Mar 9, 2009, 11:40 PM
Post #155 of 177
(10804 views)
Shortcut
Registered: Nov 6, 2007
Posts: 2667
|
spikeddem wrote: USnavy wrote: patto wrote: Thanks USNavy some very thought provoking work. It would have been fantastic if you had taken photographs of the 'fair' placement in each case. As i currently stands this asks as many questions as in answers. I suspect that the OP link cam was placed in a situation where the unused portion of the cam was extended and touching the rock. When the cam was loaded, this loaded the cam arm and torqued the axle. I doubt the axle was bent by normal cam contact forces. There already has been one case on this forum of link cams breaking from this fashion. (I say this because I have faith in OP design and quality control, the can should be fine in conventional placements.) I remember the exact place I set the cams and I could probably get a pic the next time I go climbing. Edit: This thread is less than useful.
And your post is even less useful then that... 
(This post was edited by USnavy on Mar 9, 2009, 11:41 PM)
|
|
|
|
|
spikeddem
Mar 10, 2009, 12:01 AM
Post #156 of 177
(10792 views)
Shortcut
Registered: Aug 27, 2007
Posts: 6319
|
USnavy wrote: spikeddem wrote: USnavy wrote: patto wrote: Thanks USNavy some very thought provoking work. It would have been fantastic if you had taken photographs of the 'fair' placement in each case. As i currently stands this asks as many questions as in answers. I suspect that the OP link cam was placed in a situation where the unused portion of the cam was extended and touching the rock. When the cam was loaded, this loaded the cam arm and torqued the axle. I doubt the axle was bent by normal cam contact forces. There already has been one case on this forum of link cams breaking from this fashion. (I say this because I have faith in OP design and quality control, the can should be fine in conventional placements.) I remember the exact place I set the cams and I could probably get a pic the next time I go climbing. Edit: This thread is less than useful. And your post is even less useful then that...
Less than useful means it hinders people. Advice suggesting to take a left when a right is the correct way is "less than useful." Any advice that points out that someone's advice is less than useful is actually useful itself. In that sense, my post was useful.
Then again, it was just an edit, replacing a post I had written up asking for pictures (like everyone else) before I realized there were 7 pages of this.
I feel like someone else may have mentioned it, but the axle on my red link looks the exact same as yours. They're all like that, probably.
|
|
|
|
|
zeke_sf
Mar 11, 2009, 6:24 PM
Post #157 of 177
(10703 views)
Shortcut
Registered: Apr 28, 2006
Posts: 18730
|
evanwish wrote: justinboening wrote: evanwish wrote: jt512 wrote: evanwish wrote: it seems untill we find a placement where the link cam holds and the camalot doesn't, the score is BD=1, OP=0Another victim of American education. Jay haa and how's that? all i'm trying to get at is that for that one particular place for one cam worked over anther. so there's bound to be a placement that ties it up ps: if there isn't i guess we could conclude that link cams suck for other than perfect placements i guess (which i highly doubt) It can't be the SAME placement. That's the issue. There are just far too many variables. You just don't get it, evanwish. no i get the fact that it can neve be the exact place because of head width etc, if you read above i said as close as possible. yes there are a ton of variables, but all i'm trying to get at is that in that specific section of crack, the link cam wasn't the best cam for the job. i doubt USnavy was intentionally putting the link cam in a worse position than the C4.
I doubt he knows the difference, or if you know why his "results" are almost completely worthless.
|
|
|
|
|
USnavy
Mar 17, 2009, 12:38 AM
Post #158 of 177
(10616 views)
Shortcut
Registered: Nov 6, 2007
Posts: 2667
|
Here are the placement photos. The first picture shows the entire route from the exact position where my waist was at when I fell.
The red arrows indicate the approximate location where the lobes came into contact with the rock.
Approximate orientation of C4 .4 BEFORE fall:
Approximate orientation of C4 .4 AFTER fall. It appears the inner two lobes slipped causing the cam to rotate counterclockwise during the fall:
(This post was edited by USnavy on Mar 17, 2009, 12:44 AM)
|
|
|
|
|
acorneau
Mar 17, 2009, 2:07 AM
Post #159 of 177
(10587 views)
Shortcut
Registered: Feb 6, 2008
Posts: 2889
|
I can see where if you pitched off outwardly (common lead falling technique) the cams would rotate up as rope began to become taught and then rotate down as you fell below them.
Clearly the link cam did not like the rotation during weighing and the Camalot was better about it.
|
|
|
|
|
sungam
Mar 17, 2009, 2:34 AM
Post #160 of 177
(10578 views)
Shortcut
Registered: Jun 24, 2004
Posts: 26804
|
*Ken Nichols shitz pants in rage!*
|
|
|
|
|
pmyche
Mar 17, 2009, 2:56 AM
Post #161 of 177
(10568 views)
Shortcut
Registered: Jan 21, 2004
Posts: 1160
|
|
|
|
|
|
Alpine07
Mar 17, 2009, 4:23 AM
Post #162 of 177
(10530 views)
Shortcut
Registered: Mar 1, 2007
Posts: 842
|
pmyche wrote: "...the inner two lobes slipped causing the cam to rotate counterclockwise during the fall..." No. Cams don't behave that way. The rotation is proof you didn't sling that piece sufficiently; it was pulled outward before being weighted. Your cam pulling was precipitated by pilot error, plain as day.
The cam that rotated (the BD) wasn't the one that pulled. We have no way of knowing if the OP cam rotated or not before it pulled, and even if it did makes little difference, as both of the cams were used in a very similar manner. This isn't about "pilot error," as pilot error was implied by the not so perfect placement. And the fact that it is impossible to place them exactly the same. But rather why did the OP pull when the BD did not in that situation? It is not quite so "plain as day" if you think about it a little.
|
|
|
|
|
blondgecko
Moderator
Mar 17, 2009, 4:53 AM
Post #163 of 177
(10521 views)
Shortcut
Registered: Jul 2, 2004
Posts: 7666
|
Alpine07 wrote: pmyche wrote: "...the inner two lobes slipped causing the cam to rotate counterclockwise during the fall..." No. Cams don't behave that way. The rotation is proof you didn't sling that piece sufficiently; it was pulled outward before being weighted. Your cam pulling was precipitated by pilot error, plain as day. The cam that rotated (the BD) wasn't the one that pulled. We have no way of knowing if the OP cam rotated or not before it pulled, and even if it did makes little difference, as both of the cams were used in a very similar manner. This isn't about "pilot error," as pilot error was implied by the not so perfect placement. And the fact that it is impossible to place them exactly the same. But rather why did the OP pull when the BD did not in that situation? It is not quite so "plain as day" if you think about it a little.
If your cams are walking, all bets are off. It's a completely uncontrolled variable with a large (even dominant) effect on the result. n=1 does not even come close to resolving anything. Fall 10 times on each with a short sling, then 10 times on each with a long one, and you might have enough data to come to some sort of conclusion.
|
|
|
|
|
USnavy
Mar 17, 2009, 5:07 AM
Post #164 of 177
(10511 views)
Shortcut
Registered: Nov 6, 2007
Posts: 2667
|
pmyche wrote: "...the inner two lobes slipped causing the cam to rotate counterclockwise during the fall..." No. Cams don't behave that way. The rotation is proof you didn't sling that piece sufficiently; it was pulled outward before being weighted. Your cam pulling was precipitated by pilot error, plain as day.
The cam did not walk as I said previously. I looked at it right before I fell to verify it did not move when I climb. Then throughout the entire fall all the way to rest my eyes, were on the cam. The rope did not pull outward on it. I was very careful to fall straight down without pushing out.
(This post was edited by USnavy on Mar 17, 2009, 5:08 AM)
|
|
|
|
|
a-e-jones
Mar 17, 2009, 5:52 AM
Post #165 of 177
(10495 views)
Shortcut
Registered: Jul 5, 2008
Posts: 295
|
usnavy will you repeat the test, 10 falls on the op cam in the same spot and then 10 falls on the bd in the same spot. i get the feeling you just screwed up the placement the first time since my link cams have held in more marginal placements then that, and i climb on greasy french limestone!
|
|
|
|
|
vegastradguy
Mar 17, 2009, 6:36 AM
Post #166 of 177
(10477 views)
Shortcut
Registered: Aug 28, 2002
Posts: 5919
|
USnavy wrote: pmyche wrote: "...the inner two lobes slipped causing the cam to rotate counterclockwise during the fall..." No. Cams don't behave that way. The rotation is proof you didn't sling that piece sufficiently; it was pulled outward before being weighted. Your cam pulling was precipitated by pilot error, plain as day. The cam did not walk as I said previously. I looked at it right before I fell to verify it did not move when I climb. Then throughout the entire fall all the way to rest my eyes, were on the cam. The rope did not pull outward on it. I was very careful to fall straight down without pushing out.
cant say i buy that statement...
the only thing that could cause a cam to rotate counter-clockwise (upward), would be...upward force- which, in this case, would either come from your foot tapping on the cam as you went by or an outward pull on the cam from above- which could occur as you started to fall. your weight would prevent the cam from rotating upward if the two inner lobes blew out. that it rotated and stayed that way means the lobes were engaged and holding it in position.
|
|
|
|
|
jeepnphreak
Mar 17, 2009, 5:10 PM
Post #167 of 177
(10425 views)
Shortcut
Registered: Jul 29, 2008
Posts: 1259
|
That very odd that the OP axles would bend like that. I fell on a .5 linkcam just a few weeks ago I was placing a stopper about 5/6 feet above the link cam and sliped off. That a fall of 0ver 10-12 feet pluss rope stretch. the cam held no problem. Side form a few scratcheds on the lobe surfice the cam was it still perfect condition.
|
|
|
|
|
hafilax
Mar 17, 2009, 7:35 PM
Post #169 of 177
(10366 views)
Shortcut
Registered: Dec 12, 2007
Posts: 3025
|
jeepnphreak wrote: That very odd that the OP axles would bend like that. I fell on a .5 linkcam just a few weeks ago I was placing a stopper about 5/6 feet above the link cam and sliped off. That a fall of 0ver 10-12 feet pluss rope stretch. the cam held no problem. Side form a few scratcheds on the lobe surfice the cam was it still perfect condition.
How tight was the belay in the fall? If there was any tension whatsoever in the line then the cams would have been rotated out and then back again unless the faller scraped their way down the rock. A slack belay would ameliorate that effect to some extent.
From the photos the placements aren't great and are really susceptible to moving to a bad place with any kind of rotation IMO. I often argue for direct clipping cams but in those kinds of placements I at least add a draw if not an extended sling.
|
|
|
|
|
spikeddem
Mar 17, 2009, 10:03 PM
Post #170 of 177
(10333 views)
Shortcut
Registered: Aug 27, 2007
Posts: 6319
|
hafilax wrote: jeepnphreak wrote: That very odd that the OP axles would bend like that. I fell on a .5 linkcam just a few weeks ago I was placing a stopper about 5/6 feet above the link cam and sliped off. That a fall of 0ver 10-12 feet pluss rope stretch. the cam held no problem. Side form a few scratcheds on the lobe surfice the cam was it still perfect condition. The cam axles did not bend. The cam lobes aren't lined up perpendicular to the axle in the photo. I don't know whether they're loose or not and I'd really like the USnavy to send it to the manufacturer so we can find out what the real issue is here.
My red link cam looks exactly like his from above, and it has never had a fall (except as a part of a TR anchor, perhaps).
|
|
|
|
|
zeke_sf
Mar 17, 2009, 10:21 PM
Post #171 of 177
(10327 views)
Shortcut
Registered: Apr 28, 2006
Posts: 18730
|
Since this thread keeps popping to the top of My Topics, would anybody be so kind as to summarize what I'm supposed to have learned here? Thanks.
|
|
|
|
|
jt512
Mar 17, 2009, 10:34 PM
Post #172 of 177
(10322 views)
Shortcut
Registered: Apr 12, 2001
Posts: 21904
|
zeke_sf wrote: Since this thread keeps popping to the top of My Topics, would anybody be so kind as to summarize what I'm supposed to have learned here? Thanks.
Not to post to worthless topics.
Jay
|
|
|
|
|
USnavy
Mar 17, 2009, 10:59 PM
Post #173 of 177
(10231 views)
Shortcut
Registered: Nov 6, 2007
Posts: 2667
|
hafilax wrote: jeepnphreak wrote: That very odd that the OP axles would bend like that. I fell on a .5 linkcam just a few weeks ago I was placing a stopper about 5/6 feet above the link cam and sliped off. That a fall of 0ver 10-12 feet pluss rope stretch. the cam held no problem. Side form a few scratcheds on the lobe surfice the cam was it still perfect condition. The cam axles did not bend. The cam lobes aren't lined up perpendicular to the axle in the photo. I don't know whether they're loose or not and I'd really like the USnavy to send it to the manufacturer so we can find out what the real issue is here. How tight was the belay in the fall? .
There was about two feet of slack in the rope when I fell.
|
|
|
|
|
michaellane
Apr 10, 2009, 1:32 AM
Post #174 of 177
(10136 views)
Shortcut
Registered: Feb 16, 2004
Posts: 89
|
OK ... I got the cam from USNavy and had several conversations with him ... thanks, USN ... and our QA guys are doing their thing.
The first job is to inspect and measure the cam to see how far, if at all, the thing is out of spec. Then, we'll analyze all the comments listed here, review our notes from the conversations with USN and try to figure out if anything went wrong.
I can't make any conclusions at this point, but unless there's damage to the cam, it's going to be especially challenging to come to any. From the photos and USN's comments, this rock is notoriously slick and often damp which is why so many of the cracks in that Hawaiian climbing area are bolt-protected. Evidently, they have a reputation for spitting out gear of all kinds. Perhaps a couple months of on-sight testing is in order? (Hint, boss.)
Seriously, we're interested in doing what we can to share what might be critical information about gear placement and Link Cams in particular so we're happy to run through the tests and analysis to come up with a most-likely explanation.
The process takes some time, and it could be a couple weeks, so stay tuned for more. Thanks again for everyone's interest in this.
--Lane
____________________
Michael Lane
Director, Sales & Marketing
Omega Pacific
800.360.3990
|
|
|
|
|
mobls
Aug 1, 2009, 11:56 PM
Post #175 of 177
(9966 views)
Shortcut
Registered: Nov 6, 2005
Posts: 10
|
I guess there is no followup...
|
|
|
|
|
|
. lol 
