Discussion Topic |
|
This thread has been locked |
| Messages 1 - 53 of total 53 in this topic |
Russ Walling
Social climber
This space for rent.
|
|
|
Topic Author's Original Post - Aug 25, 2005 - 08:51pm PT
|
Hi ya'll,
Busted this out of the other thread so we can rave here. Pete? you there? Shack?? Numbers guys??
Anyway, all this math and stuff was starting to make my head spin and with the way the numbers were going, it was anyones guess as to what is really going on. I'm not saying this is the right answer, but it is a start. I'll leave the numbers crunching to those in the know (Deuce??) and show what I found and noted what I guess is happening.
here ya go.. "talk amongst yourselves..."
|
|
Russ Walling
Social climber
This space for rent.
|
|
|
Topic Author's Reply - Aug 25, 2005 - 08:53pm PT
|
Cripes!!! no edit button and I spelled DAISY wrong on the file.... Try this:
|
|
'Pass the Pitons' Pete
Big Wall climber
like Oakville, Ontario, Canada, eh?
|
|
|
Aug 25, 2005 - 09:06pm PT
|
Uh, like, the co-efficient of static friction is HUGELY higher than the co-efficient of dynamic friction.
This is to say, if you just hang the weights there, it takes a helluva lot to get the daisy to move, which you know is not true. Adjustable daisies are EASY to move.
You get a 2:1 lifting advantage. I don't care if you call it mechanical or counterweight, it's 2:1 less friction through the buckle.
Adjustable daisies rock, and I refuse to climb El Cap when I can simply pull myself up using the 2:1 or so that adjustable daisies offer.
[burp]
|
|
Russ Walling
Social climber
This space for rent.
|
|
|
Topic Author's Reply - Aug 25, 2005 - 11:08pm PT
|
The above was mostly to show what a crappy pulley the buckle is/was. But, as to the real test, I sat in a sling on the locked side of the daisy. Pulled on the free end. Magically I went up with some effort. ok... did this about 10 times to get a feel for it. Now, not hanging there I pulled on the fixed end with the same feel as when I was sitting there. Guess what the dyno said? 150lbs. So, when I was pulling on the free end while sitting in a sling I was pulling 150lbs. At 150lbs of pull, I moved up, and I weigh just under 190 right now. I pulled 1ft and moved 1ft up. So I get 150lbs of effort to move 190lbs.
Elaborate???
|
|
'Pass the Pitons' Pete
Big Wall climber
like Oakville, Ontario, Canada, eh?
|
|
|
Aug 25, 2005 - 11:11pm PT
|
Voice of Bob and/or Doug McKenzie:
"That is, like, way too hard after so many beers, eh?"
And besides, unless you are ALSO a mythical internet Superhero, you can't pull 150 lbs. with one hand...
|
|
Russ Walling
Social climber
This space for rent.
|
|
|
Topic Author's Reply - Aug 25, 2005 - 11:22pm PT
|
Better hit the gym hoser.....
Ok, I used two hands, but 10 years ago I'd show you something. (it still only rounds to 1.3 : 1 )
|
|
'Pass the Pitons' Pete
Big Wall climber
like Oakville, Ontario, Canada, eh?
|
|
|
Aug 25, 2005 - 11:48pm PT
|
The gym?
The gym?! Like, take off, eh?
Why, back in the day, I used to do laps on gym 5.10. I tell you, I was bitchin'. I owned a chalkbag and everything.
|
|
deuce4
Big Wall climber
the Southwest
|
|
|
Aug 25, 2005 - 11:58pm PT
|
Nice "everyman's" test, Russ!
We'll be able to get a coefficient of friction for you shortly. Right now I'm too buzzed from Margaritas at a friends.
Your data will give us the static coefficient of friction. We could also use the minimum weight needed to keep the thing in motion (giving it an initial tug) for the dynamic coefficient.
cheers
|
|
Lambone
Ice climber
Ashland, Or
|
|
|
Aug 26, 2005 - 01:42am PT
|
"Adjustable daisies rock, and I refuse to climb El Cap when I can simply pull myself up using the 2:1 or so that adjustable daisies offer."
What happend to walking youself up your etriers?
Oh yeah, you use those stupid Russion things with the hooks...I forgot.
Pull yourself up El Cap all you want, I'll use my good old legs and save my arms for the scary free climbing sections.
|
|
'Pass the Pitons' Pete
Big Wall climber
like Oakville, Ontario, Canada, eh?
|
|
|
Aug 26, 2005 - 07:00am PT
|
My arms?
{Dr. Piton stands, and steps in front of his full-length mirror which he keeps next to his computer. Adjusting his Superhero cape, he grins at himself and raises one eyebrow, as only Dr. Piton can do. [Pete can't] After a few Superhero poses, he raises one arm to flex his bicep and .....
.... oh dear. Not very impressive, unless you like Oscar Meyer wieners. A clattering of discarded Olde English cans can be heard underfoot as the Doc makes his way back to his chair, and resumes typing}
Thank goodness for adjustable daisies.
|
|
Wrathchild
Big Wall climber
Lee NH
|
|
|
Aug 26, 2005 - 10:03am PT
|
"Dr. Piton stands, and steps in front of his full-length mirror which he keeps next to his computer."
Why don't I find that in the least bit suprising...
|
|
Irisharehere
Trad climber
Gunks
|
|
|
Aug 26, 2005 - 10:08am PT
|
You all need Rich Goldstone (rg) here. Math prof, hard-ass Gunkie, and all-round numbers guy.
|
|
deuce4
Big Wall climber
the Southwest
|
|
|
Aug 26, 2005 - 02:10pm PT
|
What we really need is that dynamic coefficient of friction, the minimum weight the two mass system (in Russ's experiment above) can continue movement after an initial tug.
Once we have that, then we can calculate how much additional work needs to be done using the adjustable daisy for a 3000 foot route. Should be significant.
The key will revolve around whether or not the 100 lbf. weight can be put into motion (even for a brief moment) by a 200 lbf. weight on the other side, with an initial tug.
Russ, waiting for your next everyman's test...
|
|
ChrisW
Trad climber
boulder, co
|
|
|
Aug 27, 2005 - 03:47am PT
|
Adjustable daisys are for wusses! and all you Aid climbers are pussys.
(I have been drinking, also)
|
|
Ed Hartouni
Trad climber
Livermore, CA
|
|
|
Aug 27, 2005 - 12:23pm PT
|
It's not just the coefficient of friction...
...the amount of wrapping of the sling around the "pully" is also a factor, as is well known in braking with a belay device (including a body belay). The forces generated in an ideal case increase exponentially with the wraps.
I believe that is a "freshman physics" calculation...
Not being familiar with adjustable daisies I couldn't quite make out the mechanism from Russ' pictures. Anyone have a schematic of the machine?
|
|
deuce4
Big Wall climber
the Southwest
|
|
|
Aug 27, 2005 - 01:34pm PT
|
Yes, what we're looking for is the total frictional force. Well, we got that for the static case, which is 150lbf., as shown by Russ's test above. Still a lot of potential calculations regarding the whole system.
The frictional torque increases with the radius of the pulley, or in this case, the radius of the cam buckle surface that the webbing passes over. In the actual pulley realm, for example, a 6" cast iron wheel running on a steel axle with no oiling whatsoever will always outperform a 3" sealed ball bearing pulley in terms of frictional losses.
Because of the innefficencies of the cam-buckle there's much extra work involved overall, but then the mechanics of the body would have to be incorporated into the efficiency question (i.e. is it more efficient for the body to pull 150 lbs twice, or 200 lbs once?).
Ah well, another hour wasted looking at an obscure problem.
|
|
Landgolier
climber
Arlington, VA
|
|
|
Aug 27, 2005 - 02:35pm PT
|
I vote that Russ takes the text labels off of the picture above and posts it to the "Pictures of your rack" thread at rc.com
|
|
Russ Walling
Social climber
This space for rent.
|
|
|
Topic Author's Reply - Aug 27, 2005 - 02:36pm PT
|
Everyman test #2: (scary in flip flops)
Loaded it up again as the picture:
1. 100lbs on each side
2. added weight to one side as before.
3. at 250 I could just get it to move and stop with a slight tug
4. added 25 more, and with a slight tug, it would move the 100lbs upwards for a few inches or so, and would probably keep going.
5. so 100lbs on one side, 275lbs on the other side, slight tug and the 100 would move upwards, very slowly, but unaided.
6. Of note, the ridges in the webbing add significant drag into the system. they kinda ping as each one goes over the buckle radius. With smooth webbing the results would
probably be a bit different.
Crunch away.
|
|
Russ Walling
Social climber
This space for rent.
|
|
|
Topic Author's Reply - Aug 27, 2005 - 02:39pm PT
|
Ed writes: Not being familiar with adjustable daisies I couldn't quite make out the mechanism from Russ' pictures. Anyone have a schematic of the machine?
Ed, the edge or radius the webbing is running over is about as wide as two bolt hangers, maybe. Pretty much just a slightly rounded vertically oriented edge.
|
|
maculated
Trad climber
San Luis Obispo, CA
|
|
|
Aug 27, 2005 - 02:49pm PT
|
Irish, doesn't Rich lurk? I think I've seen him post here before.
|
|
deuce4
Big Wall climber
the Southwest
|
|
|
Aug 27, 2005 - 04:02pm PT
|
Well, from Russ's second test, then clearly, using the adjustable daisy means more work to get yourself up each foot of vertical travel. Obviously ridiculous in the case of using the daisy only to gain vertical. There would be some chance of interesting calculations if the opposing force was less than twice the load, but not in this case of exceesive added frictional forces from the cam buckle.
If you wanted to follow in Pete's aiders, so to speak, you would want some sort of hauling pulley instead of a narrow edged cam buckle. It might begin to make sense if the opposing load was on the order of 110lbs to pull 100 lbs., due to the human efficiency of pulling smaller loads as opposed to one big load.
The reality is that Pete is also pushing up with his feet in the aiders. If he pushes up completely with his feet, the "2:1" daisy wouldn't affect any energy calculations, only in the ease of shortening the daisy. So the percentage mix would have to be figured.
In any case, the mechanical advantage of the daisy appears to be completely eliminated by the frictional forces, if we are to trust Russ's data, and the only way it can be helping is that the immediate anchoring of the adjustable daisy may be saving some energy.
that is all.
ps: check out this link for some data on pulleys:
http://oberon.ses.nsw.gov.au/resources/Vertical%20Rescue%20Friction%20Testing.pdf
|
|
mark miller
Social climber
Reno
|
|
|
Aug 27, 2005 - 04:46pm PT
|
Sometimes you just have to believe, can you prove the tooth fairy? No, but I always had a quarter under my pillow. Can you prove Santa Claus? No, but there where always gifts on Christmas morning. Can you disprove the effectiveness of adj. daisys? Well it appears so but I still like them.
I wonder if you used a petzel traxion( not the mini) with the larger pulley and a peice of cord tied to your waste if the reduction in drag would make it a viable alternative to the adj.daisy. Your carrying the pulley with you anyways. That cord could be part of your "zed" line 3 to 1 hauling system also. This Idea needs some fine tuning but it could be a better way. Problem 1.. do you carry 2 traxions or improvise something else. Problem 2 can you release the traxion under a load.ie. you sucked all the 'daisy' in and have to high step and extend your daisy to reach that next Gerberding rivet 8' away.
|
|
Ed Hartouni
Trad climber
Livermore, CA
|
|
|
Aug 27, 2005 - 05:07pm PT
|
yikes, saving energy isn't the same thing as gaining mechanical advantage...
the minimum energy you will expend going up something is just E=mgh, where m is the mass you are lifting, h is the distance you lift it and g is the gravitational constant. Divide this by the efficiency and you get the total energy...
...if you use some mechanical contrivence to lift then you are probably going to suffer in the efficiency department... e.g. friction creates heat which disipates energy, you loose it to your mechanical task at hand: lifting. At best you can brake even (2nd law of thermodynamics) but in practice efficiencies of 30% are very good... most devices are much less.
As far as I can see, the adjustable daisy is being used as a sort of ratchet, with the difference between the static and dynamic coefficients of friction providing the ratchet action.
|
|
Karl Baba
Trad climber
Yosemite, Ca
|
|
|
Aug 27, 2005 - 05:34pm PT
|
Oh the humanity!
Math and physics geek threads always manage to prove something that's plainly not true in practical experience.
First of all, one thing that the Fish line tests don't replicate is that when you pull on one end of an adjustable daisy, you are taking weight off the load end at the same time you are applying force on the pull end. Russ's test keep the weight being pulled up the same.
But also, nobody is actually advocating that you should pull yourself up El Cap by arm-hauling yourself up with an adjustable daisy. Let's say you use them in basically the same way as you would use a pocketed daisy, only they have the following advantages:
1. You can immediately and with one hand cinch yourself up to the high point that you've climbed in your aiders instead of fiddling to clip a biner or fifi to find approximately that high point.
2. If you need to let slack out on the daisy, at least with the Yates system, you just push the button instead of having to unweight yourself enough to unclip. You are also able to let yourself out gradually rather than cut loose.
3. If you placed your next piece very high, and can't reach it to clip with your aiders, it is possible to rachet yourself up into stricking distance by clipping your aiders to the ring at the pull end of the adjustable daisy. You won't find any more questions regarding the "mechanical advantage vs distance traveled upwards" once you try this. It's pretty obvious that it's far easier than climbing your aiders straightway but that you have to climb twice as far to get the same upward travel.
I only recommend this once in awhile for convenience to reach the piece. If you do it all the time, you'll wear your daisy out.
But nobody is going to calculate how much energy is saved or lost in a wall by using adjustable daisies any more than you could figure out how much extra energy would be required if you jammed thumb down all the time versus thumbs up. It's an indefinable and cumulative gain or loss depending on the efficiency of your total technique and judgement about how and when to use your gear
peace
Karl
|
|
deuce4
Big Wall climber
the Southwest
|
|
|
Aug 27, 2005 - 06:09pm PT
|
Karl, you're right in the fact that the whole theoretical aspect becomes kind of moot. Somewhat of an interesting analysis, but in the end, it just comes down to personal preference and if you don't mind resetting an adjustable daisy a thousand times per route.
|
|
Shack
Social climber
So. Cal.
|
|
|
Aug 27, 2005 - 06:54pm PT
|
Karl, you hit the nail on the head with every point.
Once you use adjustables on overhanging rock,
the benefits become glaringly obvious.
|
|
Ed Hartouni
Trad climber
Livermore, CA
|
|
|
Aug 27, 2005 - 07:19pm PT
|
Karl, with all due respect, Fish was asking about the forces, efficiencies and such... you provided a "good old practical American" response... complete with the cultural disdain for any higher understanding then "it works".
Sort of like the old gold panning 49er's who didn't much believe that geology or geologists had anything to do with finding gold...
Perhaps Chris should also ban any explanation which deviates from "common wisdom" so that we can avoid flaming each other as either ignorant hicks or over-educated idiots....
|
|
Ed Hartouni
Trad climber
Livermore, CA
|
|
|
Aug 27, 2005 - 07:24pm PT
|
that really is funny klaus....
|
|
Karl Baba
Trad climber
Yosemite, Ca
|
|
|
Aug 27, 2005 - 07:27pm PT
|
Daisies have a lot of uses besides resting. Like saving your gear and aiders when the piece that you haven't clipped rips.
But Ed, I appreciate what Russ went out and did. He is the freakin greatest.
But his test was totally screwed up up because it doesn't account for the aspect of losing weight on one side as force is applied by the counterweight itself, rather than by weights added on the other side. Get it?
Peace
karl
|
|
Shack
Social climber
So. Cal.
|
|
|
Aug 27, 2005 - 08:08pm PT
|
Chris!!!...
Klaus infered that were homos for using adjustable daisies!
Ban him!!!Ban Him!!!
Just kidding! hehe
|
|
deuce4
Big Wall climber
the Southwest
|
|
|
Aug 27, 2005 - 08:29pm PT
|
Actually, Fish's test does show that it requires 250 pounds of force to lift a 100 pounds through an adjustable daisy. The fact that in typical use the weight is distributed through pushing up with your feet (with no mechanical advantage there) just emphasizes that most of the work is done the traditional way, by a combination of stepping and pulling your own weight, without much mechanical advantage. The argument about the weight on the other side of the "pulley system" lessening is a non-issue, from an ideal-world mechanical perspective. It's not like your mass suddenly decreases.
In short, if it was a more efficient pulley, there could be some advantages in the 2:1 system in terms of effort.
In terms of the preference factor, thinking of all the thrashing I've done on overhangs, I can see the benefit there, but still prefer regular moving like a butterfly dancing in my aiders (yeah, right) with regular (simpler) daisies on general vertical.
On a side note, sorry to see you go, Klaus..
|
|
Shack
Social climber
So. Cal.
|
|
|
Aug 27, 2005 - 08:38pm PT
|
Sport climbers have rights too!
Bwahahahahahaha!!!
Chris...
It's probably already too late but,
please don't ban Klaus, that was too funny!!!!
|
|
Karl Baba
Trad climber
Yosemite, Ca
|
|
|
Aug 27, 2005 - 09:56pm PT
|
Deuce wrote:
"The argument about the weight on the other side of the "pulley system" lessening is a non-issue, from an ideal-world mechanical perspective. It's not like your mass suddenly decreases."
But I believe you're wrong, you're weight on the load side does decrease. If I pull down 100 lbs on the far side, my weight at the load side on the system decreases by 100 lbs minus friction.
Try this, hang on an adjustable daisy and try to pull yourself up just using your arms on the far side. Now reset, hang in your daisy and let somebody else try to pull you up using their arms. HUGE difference
Peace
Karl
|
|
ChrisW
Trad climber
boulder, co
|
|
|
Aug 27, 2005 - 10:01pm PT
|
I agree with Klaus.
Adjustable daisys rule and I am a wuss.
|
|
Russ Walling
Social climber
This space for rent.
|
|
|
Topic Author's Reply - Aug 27, 2005 - 11:22pm PT
|
I hate to reiterate, but here is what Russ was really saying. It is in the first post that sent PTPP over the side.
Nutshell: Pete says adjsutable daisys are 2:1.
I say, they ain't 1:1, but they sure ain't 2:1.
Pete bases his on pure numerical theory, and is correct. I sorta knew the theory, and also knew the real world. I guessed you would never get a real 2:1 out of the things. I also said most of the magic is due to gyrations and such, which of course is standing up, moving weight from side to side and applying a downward pull. I also said then that with these "gyrations" you could effectively make the friction at the buckle near zero. Because you have stood up, arched your body in and pulled on the free end there is no real weight on your side anymore. Or you are pulling on an object (your standing up body) that is already in motion.
So, back to what Russ was really saying: It ain't 2:1 except on paper, and it ain't 1:1. As my everyman tests showed to me at least, it seems to be 1.266 : 1 if you are just sitting there and pulling your fat ass up.
Seems good to me. But to flat out say you get a 2:1 mechanical advantage with an adjustable daisy is misleading and wrong, because we don't live on paper.
|
|
Shack
Social climber
So. Cal.
|
|
|
Aug 28, 2005 - 12:17am PT
|
So it shall be written,
and so it shall be done!
|
|
WBraun
climber
|
|
|
Aug 28, 2005 - 12:25am PT
|
Whew! now that we got that out of the way?
What next?
|
|
Russ Walling
Social climber
This space for rent.
|
|
|
Topic Author's Reply - Aug 28, 2005 - 12:30am PT
|
I think we should move on to FALL FACTOR..
Werner, you start it by saying you took a factor 2.4 fall onto a screamer.
|
|
Ed Hartouni
Trad climber
Livermore, CA
|
|
|
Aug 28, 2005 - 12:30am PT
|
LOL Werner... Ole!
|
|
WBraun
climber
|
|
|
Aug 28, 2005 - 12:33am PT
|
I'll just scream period if I had to take a 2.4 fall factor!
|
|
Wrathchild
Big Wall climber
Lee NH
|
|
|
Aug 28, 2005 - 04:58pm PT
|
Falling a full rope legnth, onto the belay, and you grabbed a big rock off the ledge on the way by...
|
|
deuce4
Big Wall climber
the Southwest
|
|
|
Aug 28, 2005 - 09:03pm PT
|
Apologies in advance for bringing this up again, but it occured to me that what Karl was asking for was something like the following analysis. I was getting too wrapped up in the energy analysis.
Here's the simple force analysis of what's happening with a adjustable daisy based on Fish's test:
Neglecting second and higher derivatives related to the forces involved (acceleration and changes in acceleration).
Fish could test this further by putting the load cell in line with the climber or the pulling side.
|
|
Wrathchild
Big Wall climber
Lee NH
|
|
|
Aug 28, 2005 - 09:06pm PT
|
I think I did the PO with that guy in Pic #2.
|
|
rgold
Trad climber
Poughkeepsie, NY
|
|
|
Aug 28, 2005 - 10:49pm PT
|
I don't think there is much I can add, but I can say it in a somewhat different way---if anyone is interested.
Let's forget about the precise definition of mechanical advantage. That may be fun to argue about but isn't the real point.
For clarity, consider how much force the climber has to exert to hold herself in place. If she wants to move upwards, she will have to accelerate, and this will require a force higher than the holding force. How much higher depends on how fast she wants to get moving, and isn't a property of the adjustable daisy system. Once moving, the force exerted can, in principle, drop back to the holding force level. If you're winching yourself up on an A5 placement, you'll be keenly interested in keeping the peak force very close to your holding force.
Since it has been much discussed, consider the frictionless case. The climber is, at any moment, supported by two strands. (The fact that one strand goes to the climber's harness and the other to the climber's arm is irrelevant.) The tensions in each of these strands are equal because of the assumption of no friction at the pulley point. The sum of these tensions has to equal the climber's weight, so the tension in each strand must be half the climber's weight. This means that the force exerted by the climber's arm is half the climber's weight, as many have already said.
Third, consider the friction case. The situation is complicated by the nature of the buckle. There is a cam that increases the friction significantly. When the climber pulls on the free end, the cam has to be unloaded and then the strap slides over the buckle surface. I suspect it takes more force to retract the cam than it does to hoist the climber once the cam is retracted, but the weight test doesn't allow us to make that distinction. In any case, it is all we have.
In the weight test, it takes 250 lbf to begin moving 100 lbf. This means, glossing over the mechanism by which it is created, that there is a frictional force of about 150 lbf and so an effective coefficient of friction of 150/250=0.6, once the weight starts moving. (I think a smaller value for coefficient of friction might be more appropriate here, because the 250 lbf value is what is required to "break" the cam's locking action.)
Let c denote the coefficient of friction, whatever it is, and consider the climber holding her weight W, having retracted the cam. Suppose she has to exert a force F to do this. Then the buckle mechanism provides a friction force of cF, which means the tension on the side of the daisy attached to her harness must be F-cF or (1-c)F in order for the forces at the buckle to be in equilibrium. Adding the tensions on both sides and equating the sum to the climber's weight gives (2-c)F = W or
F = W/(2-c).
Note that if c=0, we are back in the frictionless case and get the same result, F=W/2, mentioned above. If we use the value c=0.6 estimated from the weight test, we get approximately
F = 0.71 W,
in other words the climber has to pull with a bit less than 3/4 of their body weight, not the 1/2 bodyweight you'd expect from the frictionless case.
|
|
deuce4
Big Wall climber
the Southwest
|
|
|
Aug 29, 2005 - 10:39pm PT
|
Thanks Rich-
Are you a mathematician? Nice analysis. I needed the sketches to figure out what you did by logical progression.
I think the problem you mention in the beginning is significant, that the "jerk" factor in initiating the adjustable daisy will in fact increase the load on the piece considerably more than gingerly stepping up and clipping your static daisy.
cheers
|
|
Karl Baba
Trad climber
Yosemite, Ca
|
|
|
Aug 29, 2005 - 10:47pm PT
|
That's assuming that the climber hauls himself up with a jerk. Climbers getting on dicey stuff don't jerk. That folks are hauling themselve up reguarly with adjustable daisies is a myth.
Here's another example of what they're good for. You are rapping the east ledges with your pig attached to your rap device. When you get to the anchor, you clip in with the adjustable. When it's time to do the next rap, you snug up your device and voila, you are able to release the daisy under a load and go on rappel without bag hoisting.
How about a little poll. How many folks have done at least one whole wall with Yates adjustable daisies and then gone back to static? I don't trust metolius and don't know Fish's.
Peace
karl
|
|
yo
climber
NOT Fresno
|
|
|
Aug 30, 2005 - 12:17am PT
|
"Climbers getting on dicey stuff don't jerk."
Chris! Baba's in the gutter!
The key to adjustable efficiency, which apparently escaped all the eggheads, but not KB, is the wild gyrations (as in wg=3x). Drive with the legs, hip thrust (gently), flick of the wrist, and you're up the steepest shizz like a ring-tailed lemur.
|
|
Watusi
Social climber
Joshua Tree, CA
|
|
|
Aug 30, 2005 - 12:25am PT
|
Wazzat Holmes?
|
|
'Pass the Pitons' Pete
Big Wall climber
like Oakville, Ontario, Canada, eh?
|
|
|
Aug 30, 2005 - 01:31am PT
|
Duecey!
Look at your pulley in #3. Ya can't have 143 pounds on one side and 57 on the other! The forces have to be equal on both sides!
Sheesh...
|
|
WBraun
climber
|
|
|
Aug 30, 2005 - 01:34am PT
|
Look again Pete it's not what you're seeing.
|
|
deuce4
Big Wall climber
the Southwest
|
|
|
Aug 30, 2005 - 09:48am PT
|
Pete--it's not a pulley. It's a.....
Adjustable Daisy!
The free body diagram is showing the forces the moment movement begins.
|
|
Prod
Trad climber
A place w/o Avitars apparently
|
|
I especially like the part where Ed gets a little antsy with Karl and calls himself an over eduicated idiot.
Talk about analog vs digital personalities!
Prod.
|
|
John Mac
Trad climber
Littleton, CO
|
|
Karl,
In regards to your poll ... I've gone full circult from standard to adjustable and no back to standard. I'm a lot smoother and faster using standard daises!
Cheers
John
|
|
| Messages 1 - 53 of total 53 in this topic |
|
SuperTopo on the Web
|
Let us know!