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True, though most don't consider the implications of the warnings. Climbing gear fails every year, and this is accepted as part of the activity. Thanks, Tom, for being more up-front than most.Quote:
Originally Posted by ratagonia
My favorite disclaimer (Fish Products:)
http://www.fishproducts.com/miscpages/dying.html
I am curious how one can be concerned about the failure of one polycarbonate item, yet have no similar concern about (for example) a polycarbonate climbing helmet?
Si, pero...they are also designed to resist failure from impact, up to a point. AFAIK the only significant impact a Fiddlestick is designed to withstand is the impact against hard surfaces after a successful pull. If it fails then, so what?Quote:
Originally Posted by Iceaxe
I for one, am upgrading to 3/8" polycarbonate from 1/4"
that's what BluuGnome usesQuote:
Originally Posted by Bootboy
http://www.bluugnome.com/cyn_how-to/...ator_make.aspx
when it comes down after a pull, only the stick and the pull cord weight (no carabiner) combine to create impact force. Some of this is mitigated by the fact that the pull cord comes down like a noodle. The stick comes down with all the thundering force of a few pounds?.. probably would give you an annoying bonk on the head when pulled if it hit you there (without a helmet). We did a pull from about 200 feet and it fell to the ground relatively lightly. I think not having a carabiner on it helps.
Here is the start of a rappel (almost 200' ?) showing the rap rope protected with a rope protector and using a Smooth Operator around a tree. 6mm pull cord on right. Attachment 71196
Here is the view from just over the edge: note ledge w/ pothole about 70' (??) down and people at bottom Attachment 71197
Here is view from the ledge. Smooth Operator had been rapped on 3 times prior an was very solid, did not budge when rap rope un-weighted due to standing on this ledge. Attachment 71198
pull, notice it took a bit of tugging (it doesn't show that they were tugging for a good bit before the start point of the vid).
http://vimeo.com/82244976
As the engineer responsible for the windscreens and canopies on 4 DoD jet aircraft I can assure you the design, initial qualification, recurring inspection and retirement requirements for aircraft transparencies are significant. Those claimed for the fiddlestick are trivial or nonexistent. A few hundred raps over a couple years is statistically insignificant and doesn't account for the myriad of ways the public can subject an item to conditions the designer never anticipated.Quote:
Originally Posted by hank moon
All of these other items have strict qualification standards based on multiple-thousands of tests.
Fine, use the fiddlestick concept. But it's irresponsible and arrogant of ICG to lead the masses into believing that dropping lots of canyons creates a materials expert. What's the weight penalty for aluminum, 2-3 ounces? No brainer.
Since I've never used a fiddlestick I feel it's my duty to weigh in.:haha:
Shall we stop using webbing, as it is also significantly weakend by UV radiation?
Shit, if we humans get too much sun we'll die. Maybe we should stay outta canyons too? :naughty:
But seriously though, being familiar with your gear and its limitations is the name of the game.
Also, anecdotal evidence on either side doesn't suffice... I'd like to see lots of testing and numbers.
Exergy really seems like he knows what he's talking about, Tom's a very smart dude too... but until we see the numbers it's just faith in one side or the other .
-Sam
This jab only makes sense in the context of gay being "less than" straight. This is a discussion about canyoneering anchors. Please save your derisive comments about homosexuality for elsewhere.Quote:
Although he might like it, it is true that I have never played with Tom's fiddlestick :nono:
So am I, actually. Unfortunate that polycarbonate sheet is not offered in 5/16", which would be ideal.Quote:
Originally Posted by Bootboy
Tom
Since you work in the socialist part of the economy, the cost of testing is not a consideration. EACH windscreen/canopy for a modern DOD jet probably costs more than my entire budget for one year. It's easy to do a thorough and really good job of testing when you are playing with someone else's dollars.Quote:
Originally Posted by Exergy
But really, the problem is determining what tests to make and how to test them, and how to set realistic standards. I held off on producing the FiddleStick for quite some time, until I thought we had it dialed.
I just don't understand HOW you are expecting it to fail. If you would like to explain what failure mode you are most concerned about, I could carefully consider and test for that. Please advise.
What are your credentials again?
Here are mine:
BS in Mechanical Engineering from MIT (1982)
17 years experience designing and testing climbing equipment, 12 of which were at Black Diamond, the USA's #1 manufacturer of climbing equipment, at least by volume.
6 years as the USA's #1 manufacturer of canyoneering equipment.
I am certainly well known for my arrogance.
Dropping a lot of canyons does not make anyone a materials expert. Exhibit A: Ram.
Tom
Misfire on the homophobs witch hunt! The jab can make just as much sense in a straight context. i.e. if Rosanne Barr had invented a plastic ATC called the FiddleClam and I said:Quote:
Originally Posted by SRG
Although she might like it, it is true that I have never played with Rosanne's fiddleclam :nono:
It has nothing to do with orientation.
Cost is definitely a consideration as congress doesn't wants to spend money on these 40-50 year old jets but there is an expectation to keep a mishap rate in line with the rest of DoD. Testing can be expensive if hired out, research is usually cheaper so a lot of effort is put into researching the work done by others. Organizations such as SAE and ASM International are good resources. Research can skinny up test requirements.Quote:
Originally Posted by ratagonia
Here is an example of research performed by SAE on the effects of sunscreen on three different blends of polycarbonate (because not all polycarbonates are the same). Not sure if you've seen it.
http://delphi.com/pdf/techpapers/2011-01-0037.pdf
Probably right. I suspect the potential market limits the amount one would spend on accelerated testing. However, budget isn't justification for premature fielding of a life support product.Quote:
Originally Posted by ratagonia
The problem is more than initial qualification testing.Quote:
Originally Posted by ratagonia
- What constitutes an unacceptable defect
- How does one inspect the fiddlestick for hairline fractures that can develop http://www.mate.tue.nl/mate/pdfs/12930.pdf
- Will surface-scuffing hide internal defects
- What level of hazing and crazing is acceptable (again, hidden by surface scuffing)
- How does one know when the material properties have degraded to an unacceptable level
- Without cause other than time in service, when does one retire an apparently good fiddlestick
Several other concerns have already been stated and gone unanswered. Not sure why I would take the time to restate only to have the questions ignored. Any further assistance and I can PM my paypal.
Not sure what this proves either way, but you show me yours and I'll show you mineQuote:
Originally Posted by ratagonia
BS in ME, USU (2001)
Licensed Professional Engineer (2008)
Licensed Structural Engineer (2008)
Aircraft Mechanical Systems Engineer (2000-2005)
Aircraft Structural Integrity Engineer (2005-2008)
Aircraft Safety Engineer (2008-2010)
Chief Engineer for 4 DoD Aircraft (2010-2013)
Multiple 40 hour continuing education classes such as:
Failure Analysis (ASM International)
Have had the opportunity to serve as the technical lead on 6 catastrophic mishaps to include picking up body parts.
Reviewed hundreds of mishap reports going back to 1972, including cases where the windscreen or canopy failed
Did Black Diamond make any man weight rated gear from polycarbonate while you were with them; what happened to it; again, rope isn't a single point failure item since it has multiple strands
All other advertised ICG gear is made from off the shelf products and from recognized/accepted practice. It appears ICG is acting alone in manufacturing a man weight supporting product from polycarbonate and I suspect it's not because nobody else has thought of it. Rather, I suspect others have done enough research to know it's a bad idea.
Arrogance is only cool if you're always right, like Clint Eastwood. If others get hurt because of your arrogance it's uncool and only makes you out to be a fool.Quote:
Originally Posted by ratagonia
Doesn't the knot itself reduce the amount of stress that gets put on the fiddlestick so that it is less than the full weight of the rappeller? It would be interesting to see a test of the stress levels the device gets put under when someone is actually on rope. BTW I have no credentials to back up my statement, I'm just curious. Also since its an advanced tool the only people who should be using it should be able to rappel in such a manner that they aren't bouncing around and adding additional unnecessary stress to the device.
In a sense, you are correct. The stress on the stick is not easy to calculate, nor easy to measure. It is a bending force and there are all sorts of significant friction forces to take account of.Quote:
Originally Posted by TommyBoy
If one wanted to measure the stress, the best way would be to apply force on the rappelling rope until the stick breaks, then apply stress in a simpler, model geometry until it break, and that would tell you the bending stress that broke the stick.
Ascii free body diagram:
........................V.................V
===================================
...............................^... ^
Tom
Exergy wins.....if nothing else just for being an Aggie! (just had to throw that in as I am watching my Aggies play in a bowl game as I type this. Go Aggies!)Quote:
Originally Posted by Exergy
ADVANCED is not the term I'd use to describe some of the folks that are currently using the fiddlestick... which is one of the major concerns of several knowledge canyoneers.Quote:
Originally Posted by TommyBoy
Tap'n on my Galaxy G3
That's why I said should. It doesn't matter what you sell, as you said in the thread about GPS usage if you don't know how to use it, it won't help and can even hurt you. That doesn't mean that we should stop selling gps units though just because some people are using them and getting lost. Same with the FS, there is a warning on the product and if you use it you accept the responsibility of using it correctly
True dat'
Tap'n on my Galaxy G3
I remember reading somewhere about a guy testing the fiddlestick in his garage. He replaced the fiddlestick with a #2 pencil. He was able to hold almost 200#s on a pencil. Now compare that to 3/8 lexan... Not to mention the overall surface area of the stick is quite small so I can't see much deflection going on here.
I just don't see what the big deal is, the fiddlestick never even sees full body weight. A version made of alloy seems like it would get all marred up, and in turn bugger the rope.
Did a local canyon yesterday fiddled three drops, a tool that will always come with me now, especially in canyons with little to no beta. I guess in the end it's up to the user. I use one, so I must not be under the impression that this thing is gonna kill me do to catastrophic failure. My .02
Skye
Quote:
Originally Posted by hank moon
From the same webpage, found it interesting.
The text portions of the Weenie Pages are easily available to anyone who does a search on the web. I used to keep what was of interest to me that I found on rec.climbing, and I additionally went out to find more info via GoogleGroups. These days most of the good stuff is well hidden on various Internet Forums. Hopefully you will find something of interest here or maybe even learn something. I sure did. This is a boil-down of around 4000 posts. Even my bad math says that 97.4% of the newsgroups info is crap. Remember this when you do your own search for info...just because it is "there" does not mean it is true, factual, proper, or even an honest post. After wading through this muck for a while I narrowed my searches to people that really know what they are talking about....It boiled down to about a handful.
Special thanks to Clyde Soles formerly of Rock and Ice Magazine and to Chris Harmston (retired) and Tom Jones of Black Diamond.
These guys really know what they are talking about.