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beyond_gravity
Apr 6, 2003, 8:18 PM
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in horizontallys, i'm taking it that you would want the outter lobes on the bottem, right? it just seems better...or does it really matter at all?
The only reason I ask is that i'm tieing off my Friends and want to make sure i do it onto the right side.
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sheldonjr
Apr 6, 2003, 8:26 PM
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I don't think it really matters.
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petsfed
Apr 6, 2003, 9:29 PM
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It only matters on TCU's (eg 3 cam units) where the outside ones should be down for the strongest placement. For FCU (4 cam units) its not as necessary. For the most bomber placement go outside down, but if you have a choice between bombproof, but the middle two cams are down and crappy but the outside cams are down, then pick the bombproof one.
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dirtineye
Apr 6, 2003, 11:57 PM
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Well, will someone then explain why it matters if the single lobe side of a tcu is up or down if all other things are equal? I have a feeling there is no good explanation, but go ahead.
I think this is like asking if it matters if a tricam is point up or point down.
Place it in the way the piece fits best, that's what counts. Up or down on inner lobes or the single lobe of a tcu should not matter if you think about the forces acting.
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benkiessel
Apr 7, 2003, 12:14 AM
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i don't think it is like tri-cams, because i place my tri-cams in horizontal cracks with the small point down and the webbing over the top, so the webbing is not rubbing on the rock as much. for cams, i don't think it matters at all.
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petsfed
Apr 7, 2003, 12:37 AM
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Thinking about it more, I don't think there is a good reason. Mountaineering: Freedom of the Hills says so, and I'm being a brainless parrot. There is nothing in either or John Long's anchor books that implies such a thing. Old school paranoia perhaps?
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jhwnewengland
Apr 7, 2003, 12:46 AM
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You really should make it so that you can place them both ways, Whether or not a cam is more stable with the outside lobes down, there WILL be times when you want it the other way because it fits in the crack better. So either use two tie-offs, or:
I would make the tie-off long enough that it can go around the stem and sling of the cam to the other side. I know you wouldn't be able to clip the regular sling that way, but that really shouldn't be a problem - the cam would pull out of the rock before your tie-off cord broke. Also, if you really wanted to clip the sling as well you could just extend it with a draw so it was longer than the tie-off. But again, I don't think that's necessary.
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jhwnewengland
Apr 7, 2003, 12:49 AM
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Oh wait, that wouldn't work, it would get in the way of the wires. Use two tie-offs then. It really is nice to be able to use both orientations.
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calpolyclimber
Apr 7, 2003, 1:36 AM
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For what its worth, both my WC Tech Friend and Clog Cam (yes, even the sheets are the same) info sheets show the middle cam lobes down when they show the horizontal placement... My oppinion is that it does not matter.
Heres why: The forces acting on the cam head are going to be just about the same (at least on a flex stem cam) as if the cam were in a vertical, because the stem will be bent over the edge of the crack, and create a horizontal pull on the head of the cam.
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verticallaw
Apr 7, 2003, 1:38 AM
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I would assume that the reason for 2 lobes down on a horizontal placement is ideal as in the event of a shock load the weight will be more equally distributed between the two lobe and not soley a downward force on a single lobe. I usually find that having the 2 lobe down also keeps the cams in place better (walking or poping out of a shallow placment)
My $0.02
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brutusofwyde
Apr 7, 2003, 1:40 AM
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In reply to: i don't think it is like tri-cams, because i place my tri-cams in horizontal cracks with the small point down and the webbing over the top, so the webbing is not rubbing on the rock as much. for cams, i don't think it matters at all.
Tricams, and cams, should be placed in the manner that makes the most secure placement. For tricams in horizontal cracks, sometimes this will be stinger up, sometimes stinger down. Every placement is different.
The obvious solution to the conundrum of cam tie-offs is to get some modern cams with flexible cable stems. This kind of situation is what they are designed for.
:roll:
Brutus
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calpolyclimber
Apr 7, 2003, 1:45 AM
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Verticalaw- The only downward force that will be involved will be the force of the stem of the cam pushing down on the outer lip of the crack. You can imagine it as a weight (cam head) on a table with a string attached to it that hangs off the side of the table. when the string is pulled down, the corner of the table redirects the force, so the only force that the weight (cam head) feels is horizontal.
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whichwayisup
Apr 7, 2003, 6:58 PM
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With the outer lobes down, the cam is more stable and less likely to walk (at least that is what I have always been told). Shouldn't affect the holding power of it though.
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buckyllama
Apr 7, 2003, 7:05 PM
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It doesn't really matter. I didn't pay any attention to which side I tied off mine on and I've never noticed it affecting the placement. If you want to be consistant, tie them off so the outer lobes are down.
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straightedgeteen
Apr 8, 2003, 1:55 PM
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i fell on a horizontal .....aiding... i bouce tested it but it popped .... i hate TCUs any way that just from falling on one they are good other wise... any way to answer your question..... i dont think it matters !
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dirtineye
Apr 8, 2003, 5:25 PM
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Please understand that the lobes on a cam push in opposite directions and that is what holds th4e cam in place. Why the lobes are shaped like a spiral is to keep constant force all around the lobe.
now if you think about it, you'll see that since the cam lobes take whaatever pull from the axle and comvert it to opposing pulls against the sides or the seam or crack, the only way the lobes that are close together could move is if the lobes that are far apart also move, assuming the cam is well set and the rock does not fail.
The only thing that matters is, did you place you cam solidly, and did it walk or not?
It's been said a lot but one more time, place it the way it fits best. IF a three cam will fit well but a 4 cam won't, I know which one I'l be placing.
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pico23
Apr 13, 2003, 3:46 AM
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[quote="brutusofwyde"]In reply to: The obvious solution to the conundrum of cam tie-offs is to get some modern cams with flexible cable stems. This kind of situation is what they are designed for. :roll: Brutus
Actually the reason Forged friends are still around is that they are stronger and more predictable in the loading. They are not outdated. That said, I'd prefer a flexible stem in a horizontal but a tied off rigid is plenty strong and safe.
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