|
|
|
|
ASR88
Jan 20, 2011, 6:36 PM
Post #1 of 9
(1505 views)
Shortcut
Registered: Sep 23, 2010
Posts: 8
|
I am a mechanical engineering student and I have a research assignment this semester. I wanted to do something climbing related and thought it would be cool to do some testing on ropes.
I want to put a short length of rope (3-6 inches) in an instron(the machine that pulls until something breaks) and test it to failure. Ideally, I would like to try various ropes with different thicknesses, different ages (brand new vs 5 years old).
I will also try to simulate a dynamic load to see if falling on a rope degrades its integrity. For example, some people who sell their used rope boast, "this rope hasn't taken any falls!", I want to see if that even makes a difference.
My problem is I do not have a lot of money (being a student and all) so I need some people to volunteer a few inches of their rope for me. I know it is a lot to ask, but if you have an older rope, a rope you don't like, a rope you found, or even a new rope and don't mind cutting off a couple inches your help would be greatly appreciated.
Anything would be very helpful. If you're interested in contributing please respond to this post as soon as possible. Thank you so much.
|
|
|
|
|
kovacs69
Jan 20, 2011, 7:02 PM
Post #2 of 9
(1467 views)
Shortcut
Registered: Jun 16, 2005
Posts: 607
|
ASR88 wrote: I am a mechanical engineering student and I have a research assignment this semester. I wanted to do something climbing related and thought it would be cool to do some testing on ropes. I want to put a short length of rope (3-6 inches) in an instron(the machine that pulls until something breaks) and test it to failure. Ideally, I would like to try various ropes with different thicknesses, different ages (brand new vs 5 years old). I will also try to simulate a dynamic load to see if falling on a rope degrades its integrity. For example, some people who sell their used rope boast, "this rope hasn't taken any falls!", I want to see if that even makes a difference. My problem is I do not have a lot of money (being a student and all) so I need some people to volunteer a few inches of their rope for me. I know it is a lot to ask, but if you have an older rope, a rope you don't like, a rope you found, or even a new rope and don't mind cutting off a couple inches your help would be greatly appreciated. Anything would be very helpful. If you're interested in contributing please respond to this post as soon as possible. Thank you so much.
Is a couple inches enough to put in the machine? I would be willing to give you some of a rope I still have from the late 80's. It never took a hard fall, was stored in a dry dark place and was very well taken care of. I am interested to see how a rope degrades over the years. PM me your address and how much you want.
JB
|
|
|
|
|
ASR88
Jan 20, 2011, 10:06 PM
Post #3 of 9
(1411 views)
Shortcut
Registered: Sep 23, 2010
Posts: 8
|
Thanks JB, can anyone else help out?
Also, does anyone know of any climbing stores (probably online is best) that sells rope by the foot? If you have any info on that please let me know, thanks.
|
|
|
|
|
jman
Jan 20, 2011, 10:20 PM
Post #4 of 9
(1397 views)
Shortcut
Registered: May 28, 2002
Posts: 438
|
I'd also check with a local climbing gym if there is one near you, to see if you can have some of their retired lead ropes.
|
|
|
|
|
olympicmtnboy
Jan 21, 2011, 12:44 AM
Post #5 of 9
(1353 views)
Shortcut
Registered: Feb 4, 2003
Posts: 270
|
Also before you go too far down the road make sure your pull tester has enough play to deal with something that can stretch 30% and check out what has been done before like the Black Diamond pull tests on old ropes: http://www.blackdiamondequipment.com/en-us/journal/climb/qclab/qc-lab-retiring-old-ropes and the useful info in the lab section here and on Aric's new site: http://theclimbinglab.com/tiki-index.php
Oh and don't forget to read up on the UIAA certification tests to find out what they mean by a "fall" as far as rope ratings and how they do their various tests.
Good luck!
|
|
|
|
|
gblauer
Moderator
Jan 21, 2011, 2:21 AM
Post #6 of 9
(1311 views)
Shortcut
Registered: Oct 4, 2002
Posts: 2824
|
I have lots of rope sections that I can give you. Where do I send them?
|
|
|
|
|
ASR88
Jan 21, 2011, 2:56 PM
Post #7 of 9
(1254 views)
Shortcut
Registered: Sep 23, 2010
Posts: 8
|
Great information, thanks for the links.
I also checked out the local gym and they let me have a little bit.
If you guys know anyone else who might have a little spare rope please send them the link to this thread.
Thanks guys
(This post was edited by ASR88 on Jan 21, 2011, 2:57 PM)
|
|
|
|
|
trenchdigger
Jan 21, 2011, 3:42 PM
Post #8 of 9
(1236 views)
Shortcut
Registered: Mar 9, 2003
Posts: 1447
|
There are material properties of climbing ropes that are, in my opinion, at least as important as the breaking strength of the rope. I encourage you to be wary of conclusions about the safety of used or old ropes based solely on static pull test results.
|
|
|
|
|
roy_hinkley_jr
Jan 21, 2011, 4:37 PM
Post #9 of 9
(1208 views)
Shortcut
Registered: Sep 8, 2005
Posts: 652
|
In all likelihood, your instron has neither the range nor the appropriate size drums for this testing. You can't just clamp a rope for doing static tests because that affects the rope structure so it will break everytime at the clamp. You need drums about 25x the diameter of the rope and then 3 or 4 wraps around each drum. So that's a lot more rope than you're planning. And a dynamic rope will stretch a lot more than 30% before breaking. Basically you need one big frickin' machine. And it still won't tell you anything that matters to climbers...like most of Arick's "tests."
|
|
|
|
|
|
