alexey 6 #1 February 22, 2007 I'd like to costruct some kind of test device for ripcords. How to fix top side (pin and cable), to not damage them? Metal to metal contact is not a good idea, right?Lexa Quote Share this post Link to post Share on other sites
airtwardo 7 #2 February 22, 2007 I'm curious as to what parameters you plan on testing to/for and why? I don't know the methodology for ripcord testing, but when I worked in aerospace we absolutely would NOT stress test manufactured hardware that was actually going to be put into service, to anywhere near it's designed failure point. To insure the manufacturing process and tooling was operating correctly, several units at the beginning and end of a production run would be tested to failure, as well as random samples through out the batch. *unless a strength test was designed into and engineered as part of the production process. The concern is that testing a component for strength, unless done with an absolute and defined process that will in no way cause damage, becomes a catch 22 situation. You can get into a circle of having to have an overlapping test process to insure that the initial test process didn't somehow damage the product, then ya might wanna check to be sure the retest of the first test didn't screw anything up..... Kind of like the discussion on harness strength and integrity after 20 years of service, the only way to tell for sure if it's within design parameters, it to test it to failure...but then passing or not...it's broke! If you are simply wanting to pull test the ball swage or pin crimp to see if it's secure, I seem to remember seeing actual tools for that. ~ If you choke a Smurf, what color does it turn? ~ Quote Share this post Link to post Share on other sites
alexey 6 #3 February 22, 2007 For example - riser testing at 600 lbs for releasing (as per 3 ring construction manual) - ripcord testing has something near load.. ets...Lexa Quote Share this post Link to post Share on other sites
airtwardo 7 #4 February 22, 2007 QuoteFor example - riser testing at 600 lbs for releasing (as per 3 ring construction manual) - ripcord testing has something near load.. ets... Okay, gottca. I was just wondering..... ~ If you choke a Smurf, what color does it turn? ~ Quote Share this post Link to post Share on other sites
ZigZagMarquis 9 #5 February 22, 2007 I think I've seen a picture of a rig used to test reserve rip cords in Poynter's manual. I want to say it was of Sandy Reid "proof" testing a reserve ripcord a R.I., but I'm not sure. You may want to check through Poynters or call around to some gear mfgr's? Quote Share this post Link to post Share on other sites
JerryBaumchen 1,468 #6 February 23, 2007 Hi alexey, Send me an email with your personal email address (not thru dz.com) and I'll send you a photo of my ripcord tester. Jerry Quote Share this post Link to post Share on other sites
JerryBaumchen 1,468 #7 February 23, 2007 Hi twardo, I worked in a non-aviation industry and oversaw testing of metal parts for 30 yrs. Anything that was tested to the design load limits NEVER went into service; it went into the scrap bins. Our normal Proof Load Test was to 40% of design load. I would think that a test of about 100 lbs would be sufficient for a ripcord. Remember, the pull forces cannot be more than 22 lbs. Just my thoughts, other's may vary, Jerry Quote Share this post Link to post Share on other sites
riggerrob 643 #8 February 23, 2007 Hate to publicly disagree with you Jerry, but when I worked for Bulter, Rigging Innovations, Para-Phernalia and Square One, I swaged and tested hundreds of ripcords. We pull-tested most of them to 300 pounds, but if they were destined for an RSL-equipped rig, we pull-tested them to 600 pounds. All four shops had the same pattern as Sandy Reid's ... bolted to the wall ... er, a steel I-beam that held up the roof. Quote Share this post Link to post Share on other sites
bob.dino 1 #9 February 23, 2007 QuoteWe pull-tested most of them to 300 pounds, but if they were destined for an RSL-equipped rig, we pull-tested them to 600 pounds. May I ask why? Quote Share this post Link to post Share on other sites
ZigZagMarquis 9 #10 February 23, 2007 QuoteQuoteWe pull-tested most of them to 300 pounds, but if they were destined for an RSL-equipped rig, we pull-tested them to 600 pounds. May I ask why? ?? This has come up around here before.... Wasn't it, in part, because some mfgr managed to ship a bunch of reserve ripcords where the ball on the end (handle end) had be "set", but not swedged? As it goes... the "story" I heard was that the person or persons assembling the ripcords would get a "bunch" ready by placing the ball on the end and "setting" it in place with a light tap from a hammer and set it asside until they had a number ready to be swedged... but somewhere along the line a bunch of these got shipped out before swedging. In the field, it was discoverd when someone yanked hard enough on the reserve ripcord to pull the ball off... a POTENTIAL (as in I don't know if this happend in freefall... I think it was on the ground) to leave the cable & pin in place... Anyway, that's what I heard is why mfgr's went to what I've heard called a "proof test" on reserve ripcords they make... to make sure the pin and ball have been swedged properly. Isn't the cable used on reserve ripcords something like 3/32 stainless steel aircraft control cable... which specs out at something like 900 to 1000 lbs tensile strength? So a one time 300 to 600 lb pull on that wouldn't concern me too much... it would be all about testing the swedge on the ball and pin? Quote Share this post Link to post Share on other sites
JerryBaumchen 1,468 #11 February 24, 2007 Hi Rob, Not a problem. We will have to disagree on this one. IMO, the mfr sets the standards for their equipment as they want. And that is how it should be. Jerry Quote Share this post Link to post Share on other sites
riggerrob 643 #12 February 24, 2007 I would have to look up the exact wording .... but somewhere in TSO C23D, it says that ripcords must pass a tensile test that includes pulling 300 pounds for 3 seconds. If an RSL is installed, the reserve ripcord must pass a 600 pound pull for 3 seconds. Quote Share this post Link to post Share on other sites
