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michaellane
Jun 10, 2008, 6:26 PM
Post #376 of 388
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Registered: Feb 16, 2004
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Hey, All ...
We just completed the final testing a couple weeks ago and are putting together an interesting summary that I’ll link to on this thread shortly.
Nutshell: we built a fixture based on the mold of the feature we took at Josh. Dropped a bunch of weight onto cams placed in that crack and recorded what happened on a high-speed digital camera we rented for the testing.
As expected, proper placement is everything. Place a cam ... any brand or model ... in the fixture poorly and it gets spit out. Place it properly and it holds strong.
Our initial assessment regarding why the cam broke was supported in this recent testing ... because the cam was bottomed against the back of the feature, it wasn't able to shift into direction of pull and, due to the extra length of the unfurled links, leverage on those hinges caused its failure.
As for BajaJava's suggestion regarding Flare Induced Force Amplification and how it may have contributed ... we spent a lot of time on this concept and think you're right, Baja, but it's near-impossible to prove it.
It's true that as a flare angle increases, the force the cam exerts increases substantially even as the holding power of the cam decreases. To accurately measure the forces involved would require a test fixture of immense complexity. Whether FIFA played a role in the incident--or to what extent--was not determined by our testing.
What was revealed was interesting, but not necessarily revolutionary: well-placed gear holds better than compromised placements and the difference between “good” and “bad” placements can, sometimes, be extremely subtle. The idea that you can simply stuff a cam into a crack and assume it’s good is a dangerous one. We used to call it “Nutcraft” when we studied the nuances of how passive pro interacts with rock and climber and I think “Camcraft” is just as important, even if it's not always obviously so.
One interesting thing we noted was how important "setting" the piece was. A simple tug on the gear before it's loaded made a difference in whether the gear held or popped. Even some compromised placements that were spit out when we didn't "set" the piece held fast when the gear was "set" prior to the load.
When we watch the replay on the high-speed video, it’s fascinating to watch the cam during the drop. In that split-second of action, there’s a lot of stuff going on with the cam as it works really hard to hold the crack … very interesting to watch.
We’ll try to post some of it on our website and link to it from here so you can see it.
As always, if you have any questions, I welcome you to contact me. Call me at 1.800.360.3990 or email at info@omegapac.com to my attention. I’ll get the message.
Climb safe …
--ML
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getout87
Jun 10, 2008, 6:34 PM
Post #377 of 388
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Registered: Dec 30, 2007
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Michael,
That is so awesome. I'm very glad to see companies actively pursuing issues like this and following through until the end. I can tell you with all certainty that Link cams will be on my rack in the (hopefully) near future.
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spikeddem
Jun 10, 2008, 8:24 PM
Post #378 of 388
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I'm really interested in seeing those videos!!!!!!!
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healyje
Jun 10, 2008, 9:13 PM
Post #379 of 388
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michaellane wrote: Our initial assessment regarding why the cam broke was supported in this recent testing ... because the cam was bottomed against the back of the feature, it wasn't able to shift into direction of pull and, due to the extra length of the unfurled links, leverage on those hinges caused its failure.
Michael, thanks for the report. This is exactly what I was positing all along - any situation which will lead to lateral loads on the cam lobe linkages is to be avoided at all cost. And while I may not have been able to break a linkage with my bare hands and a pair of pliers in the [informal] testing Bill and I did, the fact that baja broke a second one with a tug while checking out the Josh placement for himself tells you the threshold is at a level where you do actually need to engage your brain when using them.
As you stated, anytime a cam - any cam - is slammed into place without study, you are simply gambling. And anyone who thinks there is some way cams can, or should be, designed or built to eliminate the requirement for rapid and complete brain engagement during placements is kidding themselves.
My perspect on Link Cams remains the same - it's an innovative cam design which offers unique benefits, but one which requires you to think carefully about how you are placing it, how it will be loaded, and how it needs to be slung, if necessary, to prevent it from shifting when you climb past it.
(This post was edited by healyje on Jun 10, 2008, 9:18 PM)
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JohnCook
Jun 10, 2008, 9:17 PM
Post #380 of 388
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Your last paragraph counts for all cams, not just link cams.
Care needs to be taken whenever placing gear, active or passive, to avoid any number of problems which can occur.
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notapplicable
Jun 11, 2008, 12:07 PM
Post #381 of 388
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Registered: Aug 31, 2006
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michaellane wrote: Hey, All ... We just completed the final testing a couple weeks ago and are putting together an interesting summary that I’ll link to on this thread shortly. Nutshell: we built a fixture based on the mold of the feature we took at Josh. Dropped a bunch of weight onto cams placed in that crack and recorded what happened on a high-speed digital camera we rented for the testing. As expected, proper placement is everything. Place a cam ... any brand or model ... in the fixture poorly and it gets spit out. Place it properly and it holds strong. Our initial assessment regarding why the cam broke was supported in this recent testing ... because the cam was bottomed against the back of the feature, it wasn't able to shift into direction of pull and, due to the extra length of the unfurled links, leverage on those hinges caused its failure. As for BajaJava's suggestion regarding Flare Induced Force Amplification and how it may have contributed ... we spent a lot of time on this concept and think you're right, Baja, but it's near-impossible to prove it. It's true that as a flare angle increases, the force the cam exerts increases substantially even as the holding power of the cam decreases. To accurately measure the forces involved would require a test fixture of immense complexity. Whether FIFA played a role in the incident--or to what extent--was not determined by our testing. What was revealed was interesting, but not necessarily revolutionary: well-placed gear holds better than compromised placements and the difference between “good” and “bad” placements can, sometimes, be extremely subtle. The idea that you can simply stuff a cam into a crack and assume it’s good is a dangerous one. We used to call it “Nutcraft” when we studied the nuances of how passive pro interacts with rock and climber and I think “Camcraft” is just as important, even if it's not always obviously so. One interesting thing we noted was how important "setting" the piece was. A simple tug on the gear before it's loaded made a difference in whether the gear held or popped. Even some compromised placements that were spit out when we didn't "set" the piece held fast when the gear was "set" prior to the load. When we watch the replay on the high-speed video, it’s fascinating to watch the cam during the drop. In that split-second of action, there’s a lot of stuff going on with the cam as it works really hard to hold the crack … very interesting to watch. We’ll try to post some of it on our website and link to it from here so you can see it. As always, if you have any questions, I welcome you to contact me. Call me at 1.800.360.3990 or email at info@omegapac.com to my attention. I’ll get the message. Climb safe … --ML
Thank you for both the post and the time you put into investigating the functionality of your gear under even the most unique circumstances.
Your right when you say that the use of any gear, passive or active, is a nuanced art. I think its valuable for a manufacturer to go through exercises like this, so that the end user of your product can better understand how to properly use your equipment and to know its limitations.
Way to step up to the plate. Thank you.
Oh yeah, links to video and written reports would be great, please do make public what you can.
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mtselman
Jun 11, 2008, 2:48 PM
Post #382 of 388
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michaellane wrote: Hey, All ... .... One interesting thing we noted was how important "setting" the piece was. A simple tug on the gear before it's loaded made a difference in whether the gear held or popped. Even some compromised placements that were spit out when we didn't "set" the piece held fast when the gear was "set" prior to the load. .... --ML
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reg
Jun 11, 2008, 2:59 PM
Post #383 of 388
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Registered: Nov 10, 2004
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can't wait to see and read all about your tests - thanks for doing it. goes to show that ya need to spend time learning from those that know. and not only proper placement in the feature but is the feature strong and well attached! lot to know and think about for us noobs.
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baja_java
Jun 12, 2008, 12:09 AM
Post #384 of 388
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Registered: Oct 8, 2003
Posts: 680
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thanks for posting that, Michael. look forward to seeing the summary, and more of the details. thanks again for the months-long effort, and for the openness throughout
Sean
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notapplicable
Jun 12, 2008, 3:31 AM
Post #385 of 388
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Registered: Aug 31, 2006
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mtselman wrote: michaellane wrote: Hey, All ... .... One interesting thing we noted was how important "setting" the piece was. A simple tug on the gear before it's loaded made a difference in whether the gear held or popped. Even some compromised placements that were spit out when we didn't "set" the piece held fast when the gear was "set" prior to the load. .... --ML The quote above may be very relevant to this discussion: Gear Tuggers know nothing???
I thought about reviving that thread just to rub their noses in it but had to go to work.
Gear tuggers know evvaaarrrrryyyyyy thing
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zeke_sf
Jun 12, 2008, 5:09 AM
Post #386 of 388
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Registered: Apr 28, 2006
Posts: 18730
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notapplicable wrote: mtselman wrote: michaellane wrote: Hey, All ... .... One interesting thing we noted was how important "setting" the piece was. A simple tug on the gear before it's loaded made a difference in whether the gear held or popped. Even some compromised placements that were spit out when we didn't "set" the piece held fast when the gear was "set" prior to the load. .... --ML The quote above may be very relevant to this discussion: Gear Tuggers know nothing???I thought about reviving that thread just to rub their noses in it but had to go to work. Gear tuggers know evvaaarrrrryyyyyy thing
I regularly tug on my gear. Wait? Is this my account on solonut.com? Bah. Whatever. Post it....
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knieveltech
Jun 12, 2008, 5:16 AM
Post #387 of 388
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Registered: Dec 2, 2006
Posts: 1431
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zeke_sf wrote: notapplicable wrote: mtselman wrote: michaellane wrote: Hey, All ... .... One interesting thing we noted was how important "setting" the piece was. A simple tug on the gear before it's loaded made a difference in whether the gear held or popped. Even some compromised placements that were spit out when we didn't "set" the piece held fast when the gear was "set" prior to the load. .... --ML The quote above may be very relevant to this discussion: Gear Tuggers know nothing???I thought about reviving that thread just to rub their noses in it but had to go to work. Gear tuggers know evvaaarrrrryyyyyy thing I regularly tug on my gear. Wait? Is this my account on solonut.com? Bah. Whatever. Post it....
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bill_in_tokyo
Apr 15, 2009, 9:23 AM
Post #388 of 388
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Registered: Aug 12, 2003
Posts: 243
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With apologies for resuscitating a long-dead thread, I was wondering if the summary test data referred to in Michaellane's post above is around anyplace.
I'm interested in general; but in particular, I'm interested in the paragraph that said:
"One interesting thing we noted was how important "setting" the piece was. A simple tug on the gear before it's loaded made a difference in whether the gear held or popped. Even some compromised placements that were spit out when we didn't "set" the piece held fast when the gear was "set" prior to the load."
The topic of "setting" cams came up in a thread on another forum, and this is an attempt to follow-up on the questions raised there. If there's actual test information available on this point, I'd be quite interested, and I bet I'm not alone.
Thanks in advance for any response!
(This post was edited by bill_in_tokyo on Apr 15, 2009, 9:42 AM)
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