In reply to mike kann:
Bold statements:-
> The cam in question took a 60 foot lob.
> ........rather than as I believe (having looked at the photos in some detail) in an angled position.....It is a piece of gear in its worst nightmare scenario!
> You cannot tell from this picture alone at what angle the cam was placed but I believe it was at quite a jaunty angle
and the one that really gets me:-
> I don't know but I think the whole thing is extremely suspcious and the RC forum postings do sod all but speculate - there's no hard evidance, a huge amount of hearsy and very little real hard science. If I get a chance I'll do some fag packet calcs to see if my theory is possible and get back to you...
All you've done is speculate. About placement quality, about fall length, about gear below the pulled piece. I've been through those threads and there is nothing to support either way any of your assertions, yet you seem convinced (and please correct me if I'm wrong) that CCH are being very hard done by here. The last quote is particularly unhelpful becase you claim too do some back of a fag packet analysis and then run an FE study! FE is anything but back of a fag packet. You need to have some pretty good assurances about model conditions before you can even think aboout doing that sort of study, and anything else is speculation masquerading as science. You say you didn't publish the results but you'll happpily say that a cam at 45 degrees as 5 times higher cable stresses than in a vertical pacement, without mention what model was used to demonstrate this.
I'll retain a healthy scpeticism in those FE results thanks. Russ's funkess IMHO is probably more valuable.
You also seem confused or unconcerned about the claims regarding bad brazing. You first suggest that you don't believe the claims about bad brazing
> I would dispute you comment about the braze being below "good quality".
and then lauch into an analysis of the Souders crack failure. To that p[oint, all the referneces to bad brazing relate to the blue cam that apparently failed at 900lbs with accompanying photo of suspect brazing. Plain and simple.
Nobody knows about the cause of other failures! Thats precisely why were having this discussion!
Now you agree the braze doesn't look right, but you still seem adamant that this is all waffle
As for sharing your results with CCH, can you not see that that is exactly what Russ is claiming he has tried to do, with little success?
A last point. Consider that just because the funkness test doesn't mimic the same loading scenario that a CE test might, does not make it invalid. THe most approriate test is the one that closest approximate real life loading. These cams were designed for the aiding thin, pinned out granite cracks. If a CE test doesn't mimic this, well other than a means of demonstrating repeatability and QC, it's not much use, is it.
Russ did quite a lot of testing and got what he believed to be some pretty sketch results. You looked at a bunch of photos, did an even more sketch "fag-packet" FE study and pronouced him wrong.
I have no axe to grind. I want my aliens to work, but I'm not going to stick my head in the sand and say it's all fine until I know it is. I want CCH to help me come to that conclusion. They weren't doing that until people (like Russ) started to make some noise.