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Revo 3

NegativeK · · Nevada · Joined Jul 2016 · Points: 40

Jim: "The results of my tests."

Jared: "Some engineering thoughts."

Joe: "IDGAF"

Thread: xkcd.com/386/

Jared Chrysostom · · Clemson, SC · Joined Oct 2017 · Points: 5

I’m gonna get a free Revo out of this, you guys wait and see. 

Jim Titt · · Germany · Joined Nov 2009 · Points: 490
Anonymous wrote:

The bet is he can't break the Revo on a biner with the biner in a vice? Which is the opposite of how Jim was testing, that is, with the Revo in the vice and the biner sticking up, correct? 

No, both tests were with biner in the vice, I explained this earlier.

Wayd Walker · · Three Forks · Joined Jan 2019 · Points: 0
Jim Titt wrote:
"O.k, the poor thing was pretty f#cked by now so all that was left was torsionally testing the attatchment points, just for Joe! I´d borrowed a horribly expensive recording torque meter from the guys down the road (they maintain gas turbines), made a fixture to hold the Revo and measured what I could achieve with both hands-34.07Nm (25.13ft lbs). I´m 6ft tall, weigh over 200lbs and bend metal for a living, I´m not that strong but sure not weak either!
Then I broke the Revo clipped into a 12mm round-stock HMS karabiner held in a vice- 144.02Nm (106.22ft lbs). To put this in perspective for those who aren´t mechanics the lug nuts on my car wheels are tightened to 140Nm and with the Revo it´s like trying to do this with a 2 inch long spanner."

Jim Titt wrote:
"I´m not quite clear what you mean by the breaking test being the opposite of what you meant? I fixed an HMS karabiner in my vice and twisted the Revo using a torque wrench (in the photo the revo is in the vice so I could take a picture)"

Jim Titt wrote:
"Since I couldn't break it with my hands on the Revo and doubt you can either this discussion is irrelevant posturing anyway and adding nothing of value."
Jared Chrysostom · · Clemson, SC · Joined Oct 2017 · Points: 5

The bet is that he can’t do what Jim already tried to do. It’s a pretty safe bet.

Edit to add useful info so that a) I am not contributing to the uselessness of the exchange and b) everyone understands that the Revo attachment points are just f’ing fine:

Based on Jim’s numbers as quoted above, if breaking the Revo via rotation at the attachment points requires 106.22 ft-lb (1274.5 in-lb) and his estimate of a 2-inch lever arm is accurate, you would need to apply approximately 320lb force with each hand at the outer edge of the Revo housing. In practice you will be applying the force at some distance inward from the edge of the housing and the force required will increase by a ratio of (that distance)/2.

To put the forces in perspective for those who didn’t study this stuff in school, 100 ft-lb is the rotational force generated when you hang a 1lb weight at the end of a 100ft stick. In the case of falling on a Revo attached to your harness there is just no way you could possibly apply this force to the device itself because the Revo/carabiner system is free to rotate at both ends - at the belay loop, and at the rope. 

Justice Holloway · · Oak View, CA · Joined Mar 2015 · Points: 120

For anyone interested mountainproject.com/forum/t…

Healyje · · PDX · Joined Jan 2006 · Points: 422

I will get around to it when I catch a break from work sometime in the next couple of weeks. But again, it's flimsy all the way around, not a great locking/unlocking mechanism and has a lockup mech/time most of you will want to do Justice's spring mod on for it to be acceptable to you. Definitely, have at it, but as devices go it would be my fourth choice behind the Eddy, grigri and SP, but still ahead of the Solist and SoloAid - but clearly, what the fuck do I know.

eli poss · · Durango, CO · Joined May 2014 · Points: 525
Healyje wrote: I will get around to it when I catch a break from work sometime in the next couple of weeks. But again, it's flimsy all the way around, not a great locking/unlocking mechanism and has a lockup mech/time most of you will want to do Justice's spring mod on for it to be acceptable to you. Definitely, have at it, but as devices go it would be my fourth choice behind the Eddy, grigri and SP, but still ahead of the Solist and SoloAid - but clearly, what the fuck do I know.

So showing no damage after being loaded to 26kN, which exceeds the standard for carabiners, slings, and even bolts/hangers, means that it is "flimsy all the way around". The logical conclusion from all of this data provided by Jim is that you would be hard pressed to break it in even the most severe climbing falls. Why don't you put your money where your mouth is

MP · · Unknown Hometown · Joined Sep 2013 · Points: 2
Healyje wrote: but clearly, what the fuck do I know.

That more or less sums this thread up nicely

Yann Camus · · Blainville, QC · Joined Oct 2017 · Points: 96

WoW great testing! Not sure if it was mentioned. I want to know the specifics of your drop tests: the Revo was on the 92kg mass or attached to the tower? Was there some slack in the rope allowing the mass to drop before the Revo started turning? If there was no slack, we could call it a « factor zero fall ». (Even if there was a fall because Revo takes time to activate...)  In your tests, what was the fall factor? What was the length of fall before Revo started turning? What length of rope between the fixed attachment and the Revo? Thanks!!! By the way did you see my tests (48kg in garage, on test glazed the rope, also winter tests)... THANKS Jim Titt!! Garage: https://youtu.be/8p75VDXj7mw winter: https://youtu.be/Vykr8IyFJnE 

Yann Camus · · Blainville, QC · Joined Oct 2017 · Points: 96

For you all into rope solo, this group can be of interest: https://www.facebook.com/groups/RopeSolo/ 

Jim Titt · · Germany · Joined Nov 2009 · Points: 490

Revo on the drop weight, not really any slack and about 6" of rope to the knot on the attatchment point.

Yann Camus · · Blainville, QC · Joined Oct 2017 · Points: 96

Ok so they are basically factor 0 falls. But cement dummy is much more harsh then a climber... That is good! Do you think the Revo could handle a factor 2 fall potentially generating 8-9kN? Do you think damage to the rope could be an issue? Anyone has experience of that kind with the Revo or link to such information?

Jim Titt · · Germany · Joined Nov 2009 · Points: 490
Yann Camus wrote: Ok so they are basically factor 0 falls. But cement dummy is much more harsh then a climber... That is good! Do you think the Revo could handle a factor 2 fall potentially generating 8-9kN? Do you think damage to the rope could be an issue? Anyone has experience of that kind with the Revo or link to such information?

What the falls are or what the weight is has no relevance, the Revo slips on the rope at around 3kN so with a bigger fall it will just slide further.No rope damage was seen, after multiple drops on the same section slight glazing was noticed.

Ranger Rick · · Lexington, KY · Joined Aug 2017 · Points: 44
Jim Titt wrote:

What the falls are or what the weight is has no relevance, the Revo slips on the rope at around 3kN so with a bigger fall it will just slide further.No rope damage was seen, after multiple drops on the same section slight glazing was noticed.


How many drops and how frequent before glazing?

Jim Titt · · Germany · Joined Nov 2009 · Points: 490
Blake Neville wrote:

How many drops and how frequent before glazing?

Probably half a dozen but it was so minor I didn't pay much attention. Glazing is suprisingly unimportant anyway.

Tylerpratt · · Litchfield, Connecticut · Joined Feb 2016 · Points: 40
This post violated Guideline #1 and has been removed.
Jared Chrysostom · · Clemson, SC · Joined Oct 2017 · Points: 5
Tylerpratt wrote:

{deleted by admin for not being nice}

That's not nice. Admitting that you're wrong is hard, I understand why he's not in a hurry to utterly and completely fail at breaking a Revo by brute hand force.

Healyje · · PDX · Joined Jan 2006 · Points: 422
mpech wrote:

That more or less sums this thread up nicely

And you've been lead rope soloing how long?
Jared Chrysostom · · Clemson, SC · Joined Oct 2017 · Points: 5

Clearly you haven’t been Internetting long enough to know when to quit. 

Guideline #1: Don't be a jerk.

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