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madbolter1
Big Wall climber
Denver, CO
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Topic Author's Original Post - Feb 28, 2016 - 03:35pm PT
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A Taco member ordered some heads from me, and Mark and I felt it was about time to release our Superhead, double-strength design into the wild. I'm sure that others will want to produce this sort of thing, as it eliminates the typical failure point of a traditional copperhead design. It takes a few more sleeves and a bit more cable, but there is no "weak point" in this design.
The mid-point sleeve is most-gently crimped, just enough to keep it in place, but allowing the side cables to slide through under load to equalize, ensuring that the double-strength lower loop gets all of the force.
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HoleyPants
Trad climber
California
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Jun 22, 2016 - 04:14pm PT
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Time to try and replicate this!
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Mungeclimber
Trad climber
Nothing creative to say
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Jun 22, 2016 - 05:41pm PT
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Madbolter1, I don't think a lot of folks will realize there was a specific weakness in the other designs that you reference. May want to call that out a bit.
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madbolter1
Big Wall climber
Denver, CO
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Topic Author's Reply - Jun 22, 2016 - 08:53pm PT
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I don't think a lot of folks will realize there was a specific weakness in the other designs that you reference. May want to call that out a bit.
Ah, good point.
Okay, well, I hope I don't glaze over any eyes here, but the problem with the traditional design is that it's impossible to get even the theoretical strength that you would think the single-strand of cable would give you. So, the traditional design is actually weaker than the reported breaking strength of the single strand.
The reason for this is that the cable enters one side of the lower sleeve, wraps to form the loop, and then reenters the sleeve on its other side. This means that the loop is actually asymmetrical in terms of how it loads the single strand of cable above it. Under load, the loop will pull the single strand into a slightly bent shape at the sleeve to accommodate the slight offset of the crimped sleeve, as the "up" cable enters only one side of the sleeve. Even when you look at the crimp, you can see that the "up" cable is not exiting exactly in the center relative to the "lower" apex of the loop.
But that "bent" cable-load means that not all strands of the cable are getting the force simultaneously. So, the "more loaded" strands start breaking before the "whole" cable does. And this can be observed when you systematically (and slowly) load a copperhead until breakage.
In both drop tests and hydraulic tests, we consistently found that single-strand heads were breaking significantly below the rated strength of the single strand of cable. And the breakage always occurred at or just above the lower sleeve, or in rare cases just below the "head" portion. (Both areas are where the single strand of cable can be "unequally" weighted.) So, single-strand heads are not as strong as their "rated strength" would suggest. A unit you would think is good for, say, 850 pounds is really only good for around 750-800 pounds.
The above design eliminates the "offset loading" at any sleeve in the unit. So, not only does it effectively double the strength of the whole unit, but it eliminates the design-weakness of the traditional design.
In your own replication, be aware that the double-loop formed at the bottom must be very close to "equal" in radius, or you'll just introduce "single-strand" weakness at the apex of the loop(s). You don't want one "side" of the loops getting the force before the other "side." Both apexes need to feel the force in order to ensure that you don't just break at the apex of the loops. This doesn't have to be "perfect," as the cable will "stretch" slightly. But it can't be visibly off.
In our many tests, we found that you really do get effectively double the strength of the rated strength of a single strand. And our testing got breakage incidents distributed around various points of the unit (most commonly near the head itself), which seems to indicate that there is greater "unit-integrity" in this design, as there's no particular design-introduced single point of failure.
So, the two keys to success here are:
1) Ensure that your loops are equal, so that the force hits both apexes simultaneously.
2) Ensure that the loop-forming center sleeve is loose enough that the two "sides" can slide through it, allowing the "apex" to "equalize" as much as possible. This enables "offset" pulls from the head itself to still make the forces "center" on both apexes simultaneously.
I hope that's helpful. I'll be happy to answer particular questions as they emerge. Small "market" for this sort of tech, but we've found it to be pretty confidence-inducing where applicable.
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hooblie
climber
from out where the anecdotes roam
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Jun 22, 2016 - 09:03pm PT
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hail! ... without a trace of irony
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nah000
climber
no/w/here
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Jun 22, 2016 - 09:03pm PT
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while the thread title initially made me wonder where i could find Jen Smith to determine for myself whether or not she really did give superhead, i have to say that your [mb1's] post above was of such high on topic quality, that i 'm glad i was duped and checked in... :)
and thanks for making your idea freely available to the masses...
see: doesn't socialism feel good? [sorry, i just couldn't resist...]
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mucci
Trad climber
The pitch of Bagalaar above you
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Jun 22, 2016 - 09:06pm PT
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That is a 1/8" or # 3 head correct?
3/32nd size #2 head I think would benefit from this design, but #3's are bombproof.
I make my own heads too, taken a few hard ones on the #3 heads.
Few falls on #2 butterfly rivet hangers (cinch style)
Failure of head placements is the least of my worry. I' m more worried about the scratch tip beak placements falling out ;)
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madbolter1
Big Wall climber
Denver, CO
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Topic Author's Reply - Jun 22, 2016 - 09:29pm PT
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3/32nd size #2 head I think would benefit from this design, but #3's are bombproof.
No, the example is a number 2 (which, with the head flattened, is also "#1" in the original design), which is, as you say, 3/32 cable. We totally agree about #3s, and we've not made the design in that size. The cable would be pretty unwieldy to work with in that size or larger.
The real benefit is in #0 size, which then becomes a bit stronger than a traditional #2. Put a screamer on that, and you've got a good shot at it being a fall-stopper.
Particularly in good rock like granite, and #0's head itself typically doesn't fail or sheer loose. So, cable-strength is the limiting factor to traditional #0s, which won't stop even the shortest fall; almost a good bounce will break #0 cable.
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mucci
Trad climber
The pitch of Bagalaar above you
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Jun 22, 2016 - 09:31pm PT
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Nice, hard to tell from the photo what size it is.
Never placed a 0, I will take your word for it!
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madbolter1
Big Wall climber
Denver, CO
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Topic Author's Reply - Jun 22, 2016 - 09:32pm PT
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doesn't socialism feel good? [sorry, i just couldn't resist...]
Good one! LOL
Of course, in this case no power-elite forcibly stole it from us to distribute its benefit around to the "needy." "Charity" (voluntary) is always preferable to "socialism" (force). So, yeah, we feel happy about this "distribution."
;-)
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madbolter1
Big Wall climber
Denver, CO
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Topic Author's Reply - Jun 22, 2016 - 09:35pm PT
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Never placed a 0, I will take your word for it!
Yeah, a fall from even third-loops on the next-highest placement (6-foot fall, even with lots of rope out) will instantly snap a #0 cable. Cable strength isn't even 500 pounds, and that is trivially-easy to generate in the slightest climbing fall. This new design gives you at least a fighting chance. LOL
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madbolter1
Big Wall climber
Denver, CO
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Topic Author's Reply - Jun 22, 2016 - 09:39pm PT
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where i could find Jen Smith to determine for myself whether or not she really did give superhead
That one was so sick and wrong that I hated myself for snorting in laughter. Shame on you!
;-)
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overwatch
climber
Arizona
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Jun 23, 2016 - 09:11am PT
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Mr. Jensen just sent you a private message just in case you don't receive it I am also posting here
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madbolter1
Big Wall climber
Denver, CO
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Topic Author's Reply - Jun 23, 2016 - 11:51am PT
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That's "Richard" to you, my friend. I just responded. Hey, post up. That shot you sent me was sweet!
Thanks!
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overwatch
climber
Arizona
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Jun 23, 2016 - 12:00pm PT
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Buy shot do you mean a photograph? I did not send you a photograph just a text message and I have not gotten an email back. Not surprising though with the hit and Miss nature of supertopo messaging system.
my email is jimdotyl9h@gmail
vvvvvvvv thanks I will look for it
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madbolter1
Big Wall climber
Denver, CO
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Topic Author's Reply - Jun 23, 2016 - 12:03pm PT
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Hmm, I just got an email from the guy I sold some heads to, and he included a photo. I thought that this was you. So sorry.
No, I haven't gotten a PM from anybody else. I'll drop you a note at your email address. Thanks.
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Mungeclimber
Trad climber
Nothing creative to say
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Jun 28, 2016 - 10:47pm PT
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Bump
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batguano
climber
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Bump for superhead
This is a nice looking rig, the additional amount of cable could definitely increase security on the smallest sizes. I mean, look at all those dead heads out there.... the cable was ultimately the weak link on those.
Vermin Equipment used to make a variety of swaged goods. Some double headed equalizing jobs, some had an extra sleeve on the cable for a second paste. And, if I remember correctly, there may have even been a double stranded affair. However, Forrest Gardner's most significant contribution to my bag of swaged tricks was the duckbill. Duckbills come in straight and circles, differing from a regular head, the sleeve to be pasted is pressed flat instead of being crimped. Not sure if that's an original idea from Dr. Gardner or not, but it's darned effective.
Anyway, I like where your head is at here Madbolter, thanks for sharing.
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batguano
climber
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Bump for superhead
This is a nice looking rig, the additional amount of cable could definitely increase security on the smallest sizes. I mean, look at all those dead heads out there.... the cable was ultimately the weak link on those.
Vermin Equipment used to make a variety of swaged goods. Some double headed equalizing jobs, some had an extra sleeve on the cable for a second paste. And, if I remember correctly, there may have even been a double stranded affair. However, Forrest Gardner's most significant contribution to my bag of swaged tricks was the duckbill. Duckbills come in straight and circles, differing from a regular head, the sleeve to be pasted is pressed flat instead of being crimped. Not sure if that's an original idea from Dr. Gardner or not, but it's darned effective.
Anyway, I like where your head is at here Madbolter, thanks for sharing.
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barrettpauer
Trad climber
north carolina
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Oct 10, 2016 - 12:47pm PT
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Richard,
Sorry for not posting up on this thread earlier, I just ran across it while trying to sit through a seminar on a beautiful monday afternoon. I was the guy you sold those heads to and let me tell yall, they rock! I have already used up all the ones I got and they work like a champ. They are much more confidence inspiring than a traditional head and they were able to catch a nice 25'er. Get em while they're hot!
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