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ep
Nov 14, 2003, 9:50 PM
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In reply to: dude -- you can't ignore the legs .. its part of the system that gives you 2:1
Actually, Ricardo, that isn't true. It may be part of the system, and using your legs surely reduces the amount you have to pull with your arms, but it doesn't have anything to do with making it a theoretical 2:1.
In reply to: ...pulling yourself up using a daisy and your legs is easier than stepping up on the aiders
Lambone sure didn't think so. It's not intuitively obvious to me that pulling yourself up would be better than stepping up given that leg strength far exceeds arm strength. And it sounds like it might be slower on C1/C2 than just hiking straight up your aiders. Do you suppose it isn't as cut and dried as you think it is?
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lambone
Nov 14, 2003, 10:14 PM
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In reply to: In reply to: ...pulling yourself up using a daisy and your legs is easier than stepping up on the aiders It's not intuitively obvious to me that pulling yourself up would be better than stepping up given that leg strength far exceeds arm strength. And it sounds like it might be slower on C1/C2 than just hiking straight up your aiders. Do you suppose it isn't as cut and dried as you think it is?
I agree.
I'm a wimp, therfore on a big wall I need to reduce the amount I am pulling on anything with my arms at all costs. One pitch is no big deal, but after 5 days, every little pull adds up bi time.
That is why I think adjustable daisy chains add more work for your arms. They may decrase the amount of work for your leggs, but why? I'd much rather use my leggs to climb up my aiders, then use my arms to pull myself up. This is the fundemantal lesson in climbing...USE YOUR LEGS!
With regular daisies I use my arms to balance, and my legs to walk up the aiders, faster and more energy effiecient. For those time when you really need to pull up hard with your arms on overhanging or funky stuff, I use an adjustable fifi. Pull with one arm, tighten the fifi and hang on it, but by no means to Ipull myself up with the 6mil chord attached to the fifi.
This is just how I like to do it. Everyone has their own preferance.
My overall point is that I feel adjustable daisies make your arms more tiered. Back-to-back ascents of El Cap one with and one without proved this to me. And it is not just pulling the slack in, it is releasing the buckle, and extending the daisy back to the long length, both take extra energy.
You be the judge.
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passthepitonspete
Nov 14, 2003, 10:55 PM
Post #28 of 64
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WANKERS.
Think of it this way:
You're climbing in the gym. [I know, I know..... Sheesh] You're climbing in the gym, pulling on slings on 5.8's, but because you retired from free climbing long ago, you fall off and are dangling in space on your toprope. Besides pulling on slings, there are several ways you can cheat to regain your high point.
First, you could get your belayer to pull down on his Grigri and pull you up! Dang, that's pretty much impossible, isn't it!
I know - you could grab the rope above your head and batman up it. That would work, wouldn't it? Er, uh, I guess it really only works for Batman himself, cuz like, it's pretty hard, eh? Even Super Heros like Dr. Piton can't do it.
Hey, try this - grab the rope between your belayer and the upper anchor. Pull down on that. Well, I'll be buggered! [and so will she if I can catch 'er...] Up you go. Imaginez ca.... However can this be? I mean, neither you nor your belayer could pull you up.
Unless.......
..... 2:1 mechanical advantage .... ??
Let's say, for instance, you are using traditional [i.e. stupid] daisies, and you need to climb your aiders. [A very foreign concept any more to the Doc] You reach up and grab your grab loop, and pull down with 50 pounds of force. You add another hundred pounds of force with your feet, and your lard ass of 150 pounds moves up in your aiders.
Now let's say you've changed to adjustable daisies - the Better Way - and this is a perfect world where buckles and marriages have no friction and both last for your lifetime, and people who have never met me are nice to me on the internet.
If you pull down on your adjustable daisy with fifty pounds of force, that force is pulling against the buckle, and is changed a hundred and eighty degrees plus or minus [geez, heaven help me if I don't put in the plus or minus - sheesh] so that you are also being pulled up with fifty pounds of force by the other end of the adjustable daisy you are pulling on. The net effect is that you are being pulled upwards with a hundred pounds of force.
So like, I'm sorry to p*ss on your belay ledge, but like - this isn't Big Wall Theory - it's Big Wall Fact.
Don't believe me? Put your harness on, and tie in on the end of the rope. Run the free end of the rope over a carabiner on a tree branch, grab the end and pull, and see what happens. Now replace the rope with your adjustable daisy.
You can tell I've been answering Ask Dr. Piton questions for Rock & Ice - I've got my Dr. Piton 'tude goin' full force
Note: Just because the diabolical Doc perceives adjustable daisies to be the Better Way does not mean you have to. Dr. Piton Technology is like a smorgassbord - take what you like and put it on your plate, and leave the rest in the bowls. The best way for you is what works best for you.
And as for being a wimp, Dr. Piton applauds, for he is one himself. Otherwise, he would not use adjustable daisies!
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flamer
Nov 14, 2003, 10:56 PM
Post #29 of 64
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In reply to: gave up on adjustable daisies because the extra work of pulling in the slack every move was making my arms cramp, and giving me "tennis elbow".
I try not to pull the slack out. You are right doing this every move will slow you down and tire you out. So when I'm on easy stuff I just don't pull the slack out! Sometimes I will through a fifi on my harness because it's faster to use it then take in the slack(I don't use adjustable fifi's!)
josh
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flamer
Nov 14, 2003, 11:05 PM
Post #30 of 64
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Want another Great Adjustable daisy Trick???
Put one on your haul bag. It makes getting the bag on and off the anchor/hauler a dream!
I know I know this is where "Mr. better way" (or one of his loyal followers) starts telling me about docking tether's and load release knots.
I don't use either. My adjustable daisy takes all of 10 seconds to set up and use and it works extremely well. In fact after showing it to some friends they all use it now.
You should try it You'll love it.
josh
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passthepitonspete
Nov 14, 2003, 11:19 PM
Post #31 of 64
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Please send photos!
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lambone
Nov 14, 2003, 11:34 PM
Post #32 of 64
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In reply to: Want another Great Adjustable daisy Trick??? Put one on your haul bag. It makes getting the bag on and off the anchor/hauler a dream! I know I know this is where "Mr. better way" (or one of his loyal followers) starts telling me about docking tether's and load release knots. I don't use either. My adjustable daisy takes all of 10 seconds to set up and use and it works extremely well. In fact after showing it to some friends they all use it now. You should try it You'll love it. josh
uhhh...how?
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flamer
Nov 15, 2003, 3:23 PM
Post #33 of 64
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Ok, lambone good point!
As this is off topic, I'll start another thread explaining it.....
I'd link it if I wasn't a Computer Retard...
josh
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passthepitonspete
Nov 15, 2003, 6:04 PM
Post #34 of 64
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I am a computer geek with no life whatsoever, and am far too good at this kind of thing.
Please click here to read about using an adjustable daisy to tether your pig.
Edit: This is an interesting post, actually. You won't have a hard time recognizing me - I'm the one with the egg on his face.
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flamer
Nov 15, 2003, 9:35 PM
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Thanks Pete!!
josh
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crankingclimber
Nov 16, 2003, 5:27 AM
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OK I must be really dumb or something, but I still don't believe that it's 2:1. Pete's example of climbing in the gym seems flawed to me. When you grab the rope between the belayer and the anchor and pull, yes, you do go up, and you go up easier than if just grabbing the rope going straight up from your harness to the anchor, but this is not because of a 2:1 mechanical advantage, it's because you have your belayers weight to help. When a person falls, how does the majority of the fall get stopped? By the belayers weight. Sure, some of it is held by the anchor if the person is tied in, but basically when a person is holding a fall, they're using themselves as a dead weight, they're sitting back in the harness. When the climber pulls up on the rope, he has this weight to help him. For proof of this you see the belayer FALL when the climber pulls up rope - because the belayers weight was in the system. Try Pete's experiment this way - no belayer on the other end, just grab a top rope setup with you on one end, and yard on the other end that has passed through the anchor and try and ascend. You can do it, but it's just as hard as if you were climbing a tied of piece of rope - maybe harder because of friction and the ackwardness of your arms pulling down while your whole body being pulled up from the harness.
For a 2:1 mechanical advantage there has to be 1 inch of body raised for every 2 inches of rope pulled through. This doesn't happen. Show me when it does, and I'll believe you, or point out the giant logic flaw that I'm somehow missing. Thanks
PS I'll ask a physics proffesor next chance I get and see what they say, maybe they'll point out my flaw, or maybe I'll turn out to be right...???
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coldclimb
Nov 16, 2003, 7:18 AM
Post #37 of 64
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Pete is right, people.
Sheesh.
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crankingclimber
Nov 16, 2003, 2:39 PM
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Gaha! I figured it out, took me long enough, jese, college is making me stupder or something. It required looking at my comalong for my truck to understand. The point nobody has said here, including me, is that there's 2 inches of motion for every one inch gained, but it's not pull two inches through the pulley, and raise only one inch, (which is the form of 2:1 mechanical advantage in Pete's hauling system) it's pull one inch, raise one inch, therefore 2 inches of total movement, to get only one inch closer to the anchor the daisy is clipped to. There you have it, 2:1, I knew I was missing some giant obvious point and now feel really dumb. It's wierd cause this is the kind of thing that I normally kick ass at. Now why couldn't somebody have just explained that to me at the begining? Ha, just have to hear things in the right way to glean understanding. Thanks all
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passthepitonspete
Nov 16, 2003, 4:06 PM
Post #39 of 64
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In reply to: "OK I must be really dumb or something, but I still don't believe that it's 2:1."
Dr. Piton agrees with you. You're dumb - really dumb.
{Dr. Piton reads further, the coffee begins to sink in. He is sitting in his car drinking coffee. Since he is a Hoser, he naturally got it from Tim's. If you are a Merrican, you may have no idea who Tim is. He's dead, but he makes great coffee}
Dr. Piton drives by that same open area. Hey look, the Doc thinks, there's another man out standing in his field.
OK, here is your Dr. Piton Homework Assignment:
Voice of Karl Malden: "You're on vacation and your wallet is stolen, what will you do? What WILL you do?!"
{slap!}
Karl: "Ouch. Geeez..... OK, Oh - KAY! You're on the wall, and you drop one of the pulleys in your 2:1 Hauling Ratchet!"
That's enough of Karl. The Doc resumes. Right. You somehow end up with only one "good" pulley for the Zed Cord of your Hauling Ratchet. You either have one really crappy pulley, or perhaps you don't even have one of those, and have to operate your hauling ratchet with a carabiner instead.
So my question is this - in order to get the most efficient operation, do you put the "good" pulley on top [the pulley with the 7mm cord through it] or do you put it on the bottom - the pulley with the inverted ascender on it. Where do you use the good pulley, and where do you use the crappy pulley?
I need answers, people - not "guesses". The difference between an answer and a guess is that a reason is given.
In reply to: "Now why couldn't somebody have just explained that to me at the begining?[sic]
Because sometimes to learn stuff, you have to be dumb - really dumb - first. The Doc knows this well. Ask him sometime about how not to drop your pig. I guess they don't teach spelling in college either.
Sheesh.
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karlbaba
Nov 16, 2003, 4:09 PM
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Having climbed a number of walls with standard and also adjustable daisies, I am confident in saying that anyone who feels that using standard daisies is easier on the arms is simply misusing his adjustable daisies. I know because my arms my even be weaker than Petes!
Just because you have adjustable daisies doesn't mean you have to constantly yard up on your arms to pull yourself up the rock. You can climb up your aiders as fast as you can (if it's not A3+) and immediately cinch your adjustable daisy tight and voila, you are off your arms at the highest possible point in an instant. Clipping in with a standard daisy often means straining on your arms while you find the right loop to clip. Unweighting with standard daisies often means more effort and strain. This goes triple on the portaledge bivy where you need to get slack on your daisy system to move around the bivy and sit down on the ledge.
I use my daisies to test my pieces. That gives me both hands to steady myself and brace for if the peice yanks. If the piece holds I just hang in the daisy and move my aiders up. It save arms like crazy and is fairly efficient. It's just to much fiddling to try to clip a standard daisy at the perfect loop.
Sometimes when I place a piece really high, I'll clip my aiders to the rap ring at the end of my Yates daisy. I get 2:1 advantange and fly up to the piece and slap the aiders back where they should be.
I'm never going back!
Karl
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passthepitonspete
Nov 16, 2003, 4:21 PM
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In reply to: "I am confident in saying that anyone who feels that using standard daisies is easier on the arms is simply misusing his adjustable daisies. I know because my arms may even be weaker than Pete's!"
Truer words were never spoken.
In reply to: "I'm never going back!"
Heed these words of wisdom, Young Bulls! Doing so is fundamental in your journey from YB to OB. Truely.
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mikeinidaho
Nov 17, 2003, 12:30 AM
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Listen - I KNOW the answer to this. I was the one who challenged the good Doctor.
Want some hints?
First... Use CAUTION with the term ZED pully (or "Z" for us Webster's users)... that usually implys a 3:1 pulley system. Remember, we're using a 2:1 system (Sometimes called a "C" poley), with an added CHANGE OF DIRECTION pully (without any mechanical advantage)
So - you're in your garage and you wanna pull the engine block out of your '62 Corvette. You set up a 2:1 PULLEY system just like Hauling-Rachet system.
The TOP pulley is tied to the rafter (it DOESN'T move) it's a Change of Direction.
The bottom pulley is tied to the engine (it MOVES up) it's creating Mechanical Advantage.
One end of the rope is tied to the rafter, and you're pullin' on it...
Both pulleys are old and squeek. And they're the same size.
As you haul the top pulley goes: "Sssqueeeeek ... Sssqueeeeeek..." (1:1 change of direction) Each squeek is one revolution of the pully wheel.
The bottom pulley goes: "Squeek-squeek-squeek-squeek" (2:1 mechanical advantage) This Wheel is turning TWICE as many times then the top pully, right?
You've got only ONE DROP OF OIL...
Where do you put it???
I know the answer - should I tell???
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mikeinidaho
Nov 17, 2003, 1:04 AM
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In reply to CrankingClimber/TopRoper:
FIRST: the 2:1 HAUL system on this site IS a 2:1 mechanical advantage PULLEY system! Two feet of rope gets pulled, the haul bag comes up one foot! The Haul bag weighs 100 pounds, you pull using only 50 pounds of pulling energy. Half the energy, spread out over twice the distance of rope - thus, TWO to ONE!
(None of this works out exactly - so just pretend you have a magic static rope with two friction free pulleys, this doesn't exist, but this is the "pretend" environment where we get all these terms)
NEXT: The Mechanical "easy" daisies. Yes, it's easier to pull down on the webbing as you step up. Nobody can deny that you use significantly LESS energy with the "easy" system than trying to step up while pulling on the AIDER's grab loop.
BUT - the vocabulary word isn't correct. It is NOT a "2:1 mechanical advantage PULLEY" (I say this cautiously cuz The Doctor is gunna wig on me) The correct term would be more better as "ASSISTED HOIST!" I use mechanical "easy" daisies, because they are EASIER, but I wouldn't call 'em 2:1 pulley system.
(I settled all this debate, didn't I!)
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mikeinidaho
Nov 17, 2003, 1:10 AM
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Ooops! I made a typo, the line in the previous post reads:
"One end of the rope is tied to the rafter, and you're pullin' on it... "
and it SHOULD read:
"One end of the rope is tied to the rafter, and you're pullin' on the OTHER end!"
(all better)
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squish
Nov 17, 2003, 1:46 AM
Post #45 of 64
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In reply to: You somehow end up with only one "good" pulley for the Zed Cord of your Hauling Ratchet. You either have one really crappy pulley, or perhaps you don't even have one of those, and have to operate your hauling ratchet with a carabiner instead. So my question is this - in order to get the most efficient operation, do you put the "good" pulley on top [the pulley with the 7mm cord through it] or do you put it on the bottom - the pulley with the inverted ascender on it. Where do you use the good pulley, and where do you use the crappy pulley?
I thought this thread was about daisies, not pulleys... Anyway, here's my take:
You put your good pulley on the bottom. This pulley is attached directly to the ascender on the haul line, and holds 100% of the weight. It has two strands coming up from it, each of which support 50% of the weight. One strand is fixed to the anchor, which holds 50%. The other 50% is held by your improvised carabiner pulley.
So, it's better to have the high-friction carabiner hold 50% rather than the whole deal.
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banzai
Nov 21, 2003, 4:07 PM
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In reply to: You put your good pulley on the bottom. This pulley is attached directly to the ascender on the haul line, and holds 100% of the weight. It has two strands coming up from it, each of which support 50% of the weight. One strand is fixed to the anchor, which holds 50%. The other 50% is held by your improvised carabiner pulley. So, it's better to have the high-friction carabiner hold 50% rather than the whole deal.
I would put the good pulley at the top. As squish pointed out, the bottom pulley holds 100% of the weight. However, the top pulley also holds 100% of the weight: 50% of it comes from the bottom pulley, and 50% comes from you pulling down. So the weight that a particular pulley has to hold is not the discriminating factor here. Instead, the discriminating factor was pointed out by mikeinidaho: it is the fact that the rotational speed of the two pulleys is not the same (or, if you are using two biners instead of two pulleys, the speed of the rope against the biners is not the same). However, mikeinidaho also wrote:
In reply to: As you haul the top pulley goes: "Sssqueeeeek ... Sssqueeeeeek..." (1:1 change of direction) Each squeek is one revolution of the pully wheel. The bottom pulley goes: "Squeek-squeek-squeek-squeek" (2:1 mechanical advantage) This Wheel is turning TWICE as many times then the top pully, right?
Here mikeinidaho is trying to confuse us, because he knows (I assume) that it is the top pulley that goes Squeek-squeek-squeek-squeek, and not the bottom one. So that is why I would put the good pulley at the top. My 0.02$.
Francois
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passthepitonspete
Nov 21, 2003, 5:08 PM
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There is a very simple reason I am asking you about this:
I don't know!
Despite being a professional engineer and struggling through physics and applied math classes, I'm not very good with vectors and forces and stuff. Though somehow I can build and teach wall climbing systems that work.
Mike first put this question to me, and I just don't get it!
Ordinarily, I would simply go grab my 2:1, take out one of the pulleys and substitute it with a carabiner, put it under a decently heavy load, and have at 'er. Then I'd switch the pulley and crab, and try again, and compare. You know, experiental not theoretical?
Unfortunately for me [but not for her!] I left my 2:1 with a friend in California so she could practise using it. [I even left her my Aliens, however she tells me she just bought us a set of hybrids for our rack, so it appears to have been a good investment - when Dr. Piton leaves you his rack to fondle, you just can't help but need more....]
At any rate, will someone who has a Hauling Ratchet available please go and TRY THIS?! I'm dyin' of curiosity up here!
Sheesh.
Note: Mike provided me an answer. Then he tried it as I suggested. Then his answer changed. I don't need guesses, people! I need some answers that you have tested!
I am Dr. Piton,
and I am flummoxed
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maculated
Nov 21, 2003, 5:21 PM
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There's definitely a mechanical advantage at the basest level. Don't know about 2:1, though.
Picture maculated hanging in harness: sling going through top of pull-up bar to locking biner. Another sling threaded through belay loop and through said biner. She pulls up and down repeatedly. Easier than a pull up, yes.
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ep
Nov 21, 2003, 6:29 PM
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In reply to: The bottom pulley goes: "Squeek-squeek-squeek-squeek" (2:1 mechanical advantage) This Wheel is turning TWICE as many times then the top pully, right?
No, wrong. The bag moves up half as fast as you the pull rope, but the amount of rope passing through each pulley (and hence the rotation rate) is equal.
In reply to: The other 50% is held by your improvised carabiner pulley.
You neglect the fact that you must also pull on your side of the rope with 50% of the weight of the bag, so you end up putting 100% load on the top pulley too.
-------
The force you exert on your end is going to be 1/2 the weight of the bag + the friction of the bottom pulley + the friction of the top pulley. There will be losses due to rope stretch and other mechanical slop. And if the lines in the ratchet are not plumb vertical the force is multiplied. But the overall force will be equally increased whether you add friction to one pulley or the other. In other words, in theory it doesn't matter.
I think the answer will come from the details of the ratchet setup and operation. Perhaps you can use your body to pull down at the same time as you use a gloved hand to pull up on the strand leading to the top pulley. If you do that, keep the good pulley on the bottom. Otherwise, I think you ought to just try it both ways.
In reply to: I need some answers that you have tested!
Sorry, no experimental data. I don't have a ratchet either.
In reply to: Despite being a professional engineer...
I thought you were a real estate agent?
In reply to: Though somehow I can build and teach wall climbing systems that work.
Debatable. :)
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bspisak
Nov 21, 2003, 8:44 PM
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I’m not a mechanical engineer, but here is my thinking.
Both pulleys go “squeak-squeak-squeak” because the same amount of ratchet rope is moving every stroke. The bottom pulley raises half as far as the amount of ratchet rope pulled, but the pulley spins the same rate as the other.
If both pulleys were frictionless, both pulleys hold the same load and both require the same force on each side of the pulley: half the load. However, pulleys are not ideal. In fact, the friction increases as the load increases (because that's the way friction works) and the coefficient of friction itself changes due to the deformation of the materials. This change is probably non-linear which makes this a problem for integral calculus.
Anyway, lets see how far we get with some back of the envelope calculations. Better hauling occurs when you minimize the impacts of friction in the system. This means minimize the load the bad pulley sees.
Assume we're raising a 500# load. Also assume an ideal bad pulley. This is one where the effects of friction are unaffected by load (counter to what I said above). In these examples, the bad pulley requires an additional 25# of force to overcome the affects of its friction.
Case 1) Both pulleys ideal: The total load on the bottom pulley is 500#: 250# to the fixed end of the ratchet line and 250# to the top pulley. The total load on the top pulley is also 500#: 250# from the bottom pulley and 250# to the haul end of the line. The hauler has to pull 250#.
Case 2) Bottom pulley is bad, top pulley is ideal: The total load on the bottom pulley is now 525#: 250# on the fixed end, 275# to the top pulley (extra 25# required to overcome its friction.) The top pulley now sees 550#: 275# to the bottom and 275# to the hauler.
Case 3) Top pulley is bad, bottom pulley is ideal: The total load on the bottom pulley is now 500#: 250# to the fixed end, 250# to the top pulley. The total load on the top pulley is 525#: 250# from the bottom pulley and 275# to the hauler.
So, it appears in both cases in which we use a bad pulley, the hauler has to haul the same amount of weight: 275#. It doesn't matter which pulley is used for the bad one!
But wait. This isn't reality. In reality, the bad pulley is not an "ideal" bad pulley. The bad pulley actually doesn't exhibit the property that it always requires 25# to overcome its friction. It will require more force, the higher its load. So say at 500# it requires 25#, and perhaps at 550# it requires 30#.
In case 2 above, the load on the top pulley is 550# and the load on the bottom pulley is 525#. Thus, the load on the bad pulley (in this case the bottom one) is 525#.
In case 3 above, the load on the top pulley is 525# and the load on the bottom pulley is 500#. Thus, the load on the bad pulley (in this case the top one) is again 525#.
Again it doesn't seem to matter! Ahhhh.... but wait. This still isn't reality. There are no ideal pulleys! Again assuming ideal bad pulleys, look at the two cases again. One bad pulley requires 25# additional; the worse pulley requires 50# additional force.
Case 2b) Bottom pulley is worse: The bottom pulley now has a load of 550# and the top pulley 625#. The hauler sees 325#. (You work out the details!)
Case 3b) Top pulley is worse: The bottom pulley sees 525# and top 600#. The hauler still sees 325#.
In case 2b, the worse pulley (bottom) sees 50# more than nominal. The other pulley (top) sees 125# more.
In case 3b, the worse pulley (top) sees 100# more than nominal. The other pulley (bottom) sees 25# more.
Hmmmm…. now things are getting ugly. If the bad pulleys are linear, and say the worse one adds 10# each 25# over nominal and the bad one adds only 5# each 25# over nominal…. [scribble scribble scribble] uhh…. it doesn’t seem to matter.
What if they’re non-linear? There's probably a neat little formula for this in mathlab. At this point, I really don’t care anymore. Engineering makes my head hurt, and non-linear equations were never my strong point. At first, it looked easy to solve, or I wouldn't have even bothered getting this far. Now I’ve decided I have better things to do, like wax my snowboard. Somebody else figure this out. I’ll carry two GOOD pulleys my next time on a wall.
As Pete would say, "sheesh."
Brian
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