Gear4Rocks Plastic Nuts Review

Isaac Dority wrote:A body free falling for a distance of around 7 feet will atain a velocity of around 21.2 feet per second at the end of seven feet.

Correct.

Isaac Dority wrote:At this point the rope will begin to take weight and stretch. A static stretch factor of around 30% could be assumed for most modern ropes. With about 25 feet out, this means that Phil fell for an adittional 7.5 feet before stopping. During this deceleration his force maxed out at around 139.78 lbs.

Close, but not quite. Assuming a uniform deceleration, he will need to decelerate at a=(21.2ft/s)^2/(2*7.5ft) = 30ft/s^2. For this to occur the RESULTANT force on the climber will need to be F=ma=(4.69slugs)(30ft/s^2)~140lbs, which is what you said. But you stopped one step short. In order for the RESULTANT force on the climber to be 140#, the force in the rope needs to equal 140# plus any other downward vertical force acting on the climber (gravity). Thus the tension in the rope will be about 140 + 150 = 290#.

Assuming the belay side of the rope takes 2/3 of the climber side tension due to friction, the force on the nut would be 1.67x290=484#, or about 2.2KN.

Yes I'm a nerd.

Cheers,
Cory

muttonface wrote:How about figuring out an equation that defines the direct correlation between your compulsion to spray about your academic accolades and your pompous prickish behavior.

Bravo.

NNEEEEEEEERRRRDDDS!!!!!!!!!!!!

youtube.com/watch?v=ocrO_94…

Phil Lauffen wrote:However, we were not able to remove the nut. ... If someone is able to remove it from Captain Natural I would love to have it back

Who ever heard of asking pirates to return BOOTY?!

As for the technical difficulties, I have the following response:

muttonface wrote: Also, a lead fall of 7-9ft is 100% of the time going to put at the very least the weight of the climber on the protection and the probability that a fall of that length will produce at least 1kn of force on the piece fallen on is very high (unless the climber is absolutely tiny).

I didn't say he was right, I said he was wrong before you even posted. I said, furthermore, that your correction of him was also off by at least a factor of two, a point which you can either concede right now and step down of the "I'm right" soap box, or continue to defend... I advise the former.

If you didn't read your own post, then you missed this:

muttonface wrote: Also, a lead fall of 7-9ft is 100% of the time going to put at the very least the weight of the climber on the protection...

Much more informed and intelligent would have been to say:
"at the very least twice the weight of the climber on the protection"

So I told you to balance the forces and said that EVEN HANGING STATICALLY it is twice the weight of the climber on the gear (not just once) and so a fall would certainly not be the weight of a climber, but more than twice the weight on a climber. And you proceeded to insist 1) that you indeed knew what I was talking about and 2) you were right. Well you were wrong on both counts.

If you are going to pick a fight with a nerd, you should be more careful. Your effort to barf up a bunch of stupid insults doesn't make your correction of him any more right or your attempt to rebut my correction of you any more right.

Both force applied by a dead weight and a fall, regardless of the movement of the rope, are "static" so far as the protection is concerned. In both cases, the protection is in a force balanced state and is not being propelled into space. And if a static "rest" on gear produces twice the weight of the climber, then most certainly saying that a fall produces

muttonface wrote: at the very least the weight of the climber on the protection...

is ignorant.

As for the soundbytes, then I say the following:

First 2 rules when you don't know what you or the other guy is talking about:
#1) Don't say:

muttonface wrote: Idk what you're talking about.

#2) Don't bring foul language into it, IE:

muttonface wrote: comparing static weight to a lead fall is like comparing assholes and oranges.

unless you want a proportionally disrespectful response.

muttonface wrote: I'm well aware that the anchor that holds a fall, even statically, still takes anywhere from 1.6 to roughly 1.8 times the force that the climber feels. The belayer feels about 2/3 of the force that the climber feels.

You want a nerd war? OK.
Should I even point out why that isn't right either? You are trying to look smart here, but you are failing. What is the difference between what the belayer "feels" and what happens at the gear if the difference is friction? Your 'model' is wrong again. You don't look much smarter for trying to equate the belayer and the protection, if you get right down to it. The closest thing to what is going on one one side of the protection is what is going on on the other side, unless there is only one piece of protection. And even then, now YOU are settling in dynamic and static friction and confusing hanging with falling. I was just saying that in any case you need to balance the forces in a system, no matter your system, and I simplified that to static as an example to make it easier to understand. It is not difficult to follow the logic that if hanging produces about twice the force of the weight of a climber, then stating that falling produces at least that force (as opposed to twice that force) is a poorly considered statement.

muttonface wrote: I would like you to quote where I said the anchor only feels one side of the rope's fall or that the behavior of the rope, excluding dynamic stretch differs statically and dynamically.

OK, If you insist:

muttonface wrote: Also, a lead fall of 7-9ft is 100% of the time going to put at the very least the weight of the climber on the protection...

There I have done your bidding. Do you feel better?
You should have said 'at the very least nearly twice the weight.'

muttonface wrote: I just drink beer and get laid every once in a while so it only looks like I'm not smart.

It might be one of the reasons, but its always been my experience that people that are smart have no trouble at all drinking beer and getting laid. They just don't bring it up in the context of force balance modeling...
There are a multitude of reasons why that supposed 'contrasting characterization' of me is funny. I won't bother listing them. But then again, you didn't know anything about a force model and kept talking... So why should I be surprised that you don't know anything about me, but keep talking? It seems to be a pattern for you.

muttonface wrote: Rule number two: You should probably wait to proclaim someone wrong until they actually say something wrong and not just "if" they happen to agree sometime in the future.

Ummm... you said something wrong. Several times now. Keep it up.

So, would one of the nerds please get to the point? Will the plastic nuts withstand the forces generated by a fall or not?

Keep in mind Phil is Phat.

muttonface wrote: I retire from this flamefest as I would have better luck trying to discern the page number of a history textbook that a 70 year old Alzheimer's victim read when he was 13.

Yep. Expect it to go that way when you flame it up, but had it wrong.
When you are right and a bit of an A-hole, you are still right. But when you are wrong and a bit of an A-hole, you are just wrong.

muttonface wrote: Have a swell evening.

Thanks, I did.

I'm just glad its not my nuts...gotta love the entertainment of MP