Is this cam safe? Seasoned climbers remember!

the schmuck wrote:Regarding horizontals, they actually do okay. You slide the plastic cover all the way to the end, which allows the cables to bend at the head of the cam. Never fell on one in a horizontal, but have aided off of them in horizontals, and they were none the worse for wear.

good call. this will help. as long as the placement isn't super deep.

teece303 wrote:That number on the cam in pic #2 is the date marking, no? It says "3174?" Or maybe "8174" or "0174." If the scheme on these is the same as what I know, that first number is the last digit of the production year. Thus, my old 3rd gen Camalots all start with a "4," which I know means mine were manufactured in 1994. So you have an idea if age. If it's really a three, that would seem to indicate 1993, but others have said these ceased production in 1992. Hmm.... They don't look old enough for 1983. Maybe that's a "0" and it was made in 1990. Maybe those number didn't mean the same thing then.

the numbers are 3124?????????

thanks again for all the input. impressive this gear lasts so long. although, i think its clear that my cam was lightly used.

IMO they're not at all safe and should have been removed from use ages ago. This one is a slightly later version U-stem, but the issue is the same.

In a nutshell, due to clearances needed for assembly the lobes are not supported by both axles when loaded at past 50% expansion the axles will bend easily and allow the device to track out of the placement.

In the test fixture:

What it looked like afterwards. Note the uneven wear on the inside lobes, indicating bending axles:


How the axles looked after disassembly:


Notice the size of the clearance hole in the slot in the lobe and the extended flattened area resulting from it tracking out:


And the amount of space there is between the smaller diameter in the axle and the clearance hole in the opposing lobe, which is what allows it to bend so easily:


And just for fun, here's a graph of the force it took to pull it from the test fixture. The long flat section of applied force is due to the cam lobes continuing to rotate as the axles go U-shaped, up until it finally pulled from the fixture upon tipping out. I used to have video of it somewhere, but no idea where it got to.


Just my $0.02 and YMMV.

Hey, that's a good excuse to throw out the few remaining I still have. They were great starting out, but that's about it.

Aric, that looks like a peak load of 9kn. Unless you're using it as your only piece for a hanging belay with hard moves before the first gear on the next pitch, I don't see an issue.

They are creek filler pieces at this point for almost everyone who owns them. They'll likely never be more than 10' above the last piece and also due to clumsiness, rarely placed at the crux.

I feel like it would be anti-semitic to retire my old .5's and .75's.

True, peak load of 9kn. Which is well below rated strength, and with a particularly nasty/unpredictable failure mode. And that 9kn would have been much, much lower had it been placed at 60% expansion.

Also take note that force on the top piece is almost double the force seen by the lead climber, so probably not a good idea to trust them for high FF placements or anything approaching 50% expansion.

Btw, seeing as you're lopping off half of the range to keep from running into this issue, a single axle piece would have more range and therefore be more useful.

Ymmv.

Edit- I'll see if I can dig up that video... Watching it twist and bend was far from confidence inspiring.

Nope. It's a museum piece in my view. Despite the fact that they were the schizz when they came out, I've retired all mine. There's a reason the Chouinard/Black Diamond co. stopped making that design. Aric has one. The prime one as I remember it was that the cams were made out of harder alum. T-7075 and between that, the angle and the skinny cam width, they didn't stick as well and had an increased chance of popping out. Fortunately, about everyone who bought them was operating with or still remembering the maxim that "the leader must not fall".

CAN YOU USE IT? Sure.

IT IT SAFE? Sure, in a way, as long as you respect the limitations.....certainly don't rely on it as a Jesus piece, unless you are looking to meet Jesus of course. It would still be good for toprope anchors.

IS THERE BETTER STUFF OUT THERE NOW? ABSOFRIGGANLOUTLY!

And I'm the guy that bought used Metolius cams that didn't have any slings on then and had Metolius put slings on them for my sons first cams. I'd never give him one of these.

Thanks for the post Aric. I always like concrete data, i'd like to see that video as well. I think my conclusion is that this cam will stay at home, even though it is in great shape. its a nice little piece of history to hold on to. ill put it next to my hexes.

Haven't found the video yet, but did find the writeup I did for the test ages ago. Turns out it was far worse than I recalled.... That 9kN failure was the *4th* attempt to break it, and the only one that damaged it. The previous 3 attempts left it working just fine in spite of pulling from the fixture at ~4.8kN, ~6.6kN, and ~7.5kN (ballparking off the chart, as I don't have the actual results in front of me).

During those first 3 attempts, the cam would slip and allow one or more lobes to tip out while the others compressed. In this pic, the green lobes both tipped out while the silver inner lobes compressed. Note how the tipped out green lobe is actually contacting the fixture on the opposite side!



In this pic the lobes on one side tipped out while the other side compressed. (This is actually the pic I used in the post yesterday, which I had mistaken as being a pic of the placement. Per the write-up it actually shows how the cam rotated as force was applied.)



Mind you, there was no permanent damage to the cam from these attempts, other than some metal scraped off the lobes:



Axles look good too:



As for that 9kN failure, it seems when I posted the pics yesterday I missed noticing that the cam didn't just go U-shaped and pull from the fixture at 9kN, it *actually came apart*. Apparently the damage marked with an arrow is from a nut tool during attempts to get it unstuck from a crack. There was no corresponding damage to the side plate, so likely unrelated.



Note that the peen on the side plate on the other side was also disturbingly small and about to pull through:



Scary stuff.

Chouinard Equipment built its reputation at least partly on the claim that ALL of their protection was tested to half its rated strength, and a significant percentage (10%?) of the gear made was tested to destruction. I always assumed that when the employees bought Chouinard's assets and formed Black Diamond, they would continue with a similar level of quality control. Is this not the case? Or did they just test these units at less than 50% expansion?

No idea.

What I can say is I had a long, rather unpleasant conversation with (blanking on his name.... Reps BD here on the East Coast, was one of the original employees who bought out Chouinard IIRC) at one of the New River Rendezvous a couple years back, which resulted in me being asked by the NRR folks to remove all BD gear from my display of broken equipment (our of fear of pissing off a sponsor). He had no desire whatsoever in discussing the how or why it failed under spec and was content to ignore it based on the gear being used, not new, and the equipment used to pull test it not 3rd party lab certified.

Aric, are you saying that current BD double axle cams don't have the same problem re. oversized "axle clearance holes"?

I was there when a BD cam, even badly mangled from an earlier test, outperformed nearly all the Aliens in your test rig. IIRC it was a red (#1) Camalot.

And the details of your rig were discussed extensively back then, I still find value in what you did, but your test fixture surfaces were much less rough than the test standard. Most cams failed by pulling through the fixture.

Correct; the design appears to have changed with the single versions, with the axles being much, much better supported, a single large diameter, and the arced slot in the lobes close enough to the axle in it that it will share in the loading.

And yup, that Red Camalot did indeed outperform most of the Aliens tested. Was a pre-C4 single stem though, so didn't suffer this problem.

As for roughness of that test fixture, the *only* cams that had issues with it were U-Stem BD and CCH Aliens. Pretty much everything else would break rather than pulling out, including oddball designs of mine using 18 to 20 degree cam angles and 6061t6 lobes.

BTW, the U-Stem BD and CCH Aliens both exhibited the same issues with the newer fixture, which was machined to the maximum roughness allowed per the UIAA spec.

I got a # 2 with the code 3005 on it. Where can I get some info on this piece? Also thanks for the warning , I 've really checked this cam and it does have a crack in the head that I missed before.

Thanks for the refresher, and the update, Aric!

Aric Datesman wrote:Correct; the design appears to have changed with the single versions, with the axles being much, much better supported, a single large diameter, and the arced slot in the lobes close enough to the axle in it that it will share in the loading.

The head of stemmed Camalots is also centered between the middle cam lobes supporting the axles. The initial axle deflection caused by the lobe axle tolerances are restricted by the centered head. Additionally, the centered head prevents the middle lobes from collapsing inward as the springs compress.

Bummer. The only copy of the videos I could find were low res to the point of not being able to see what was going on. Oh well....

I just watched your video, Aric, a couple days ago. On a SupetTopo thread? It's online somewhere.

I'd find that very surprising, as I shut down the Youtube account they were posted on ages ago and don't recall ever posting a video directly to a climbing site.