Journey 75 I180 recovery failure. No damage.
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jahall4
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Yeah, that looks to be the failure mode that led to the technique and development of the Recovery sled...
"After a failed inflation, that could not be explained, on a 72" chute at SEARS in Oct. 2016 I started investigating. Flight video from test flights showed that the shroud lines could pull out of the pack even on much smaller rockets, using much smaller chutes. Apparently, the pack thrashing about in the air stream could twist pulled lines fouling the chute. This is more of an issue on larger chutes given the JLCR’s lesser ability to compress the pack. The pack gets bigger, but of course the JLCR does not scale up with the pack.
It seemed reasonable that if the chute could be kept immobile relative to the harness that could not happen. The recovery sled does just that when properly configured, because the chute pack cannot move independent of its harness attachment point. They must move together until the JLCR releases. This can be readily inspected when packed. The chute pack is held to the sled by the JLCR, the sled is fixed along the harness at each end so where the harness moves so does the pack, and vice-a-versa."
Thank you Allen. I appreciate your help. Is there a thread explaining more about the sled idea that you know of?
jahall4
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What I posted here is the best summary I have regarding why and when the sled was developed. If you have questions, I'd be the one to ask,
but the bottom line is that the sled keeps the chute pack immobile relative to the harness.
I have a Journey 75 that I flew this past weekend on an H182 redline motor, w/ a JLCR set to 400" and a recovery sled from Allen Hall. The parachute was a 30" elliptical from Fruity Chutes.
This video of that flight on my youtube channel did not come out that well at all. It was just taken with my cell phone:
I have the JLCR with the rubber band replaced w/ a slightly longer elastic hair tie (the kind used for a pony tail). I have only used the JLCR and sled twice, but am very happy with the results.
I had a rocket I spent months on go from a work of art to a smashed piece of junk in a matter of seconds. That spurred me to get the sled and use it w/ the JLCR.
This video of that flight on my youtube channel did not come out that well at all. It was just taken with my cell phone:
I have the JLCR with the rubber band replaced w/ a slightly longer elastic hair tie (the kind used for a pony tail). I have only used the JLCR and sled twice, but am very happy with the results.
I had a rocket I spent months on go from a work of art to a smashed piece of junk in a matter of seconds. That spurred me to get the sled and use it w/ the JLCR.
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I forgot to mention that I also used the coil winding tool from Allen Hall to help prevent things from getting tangled up.
Beautiful!
-Slick-Ice
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I leave all of my parachute lines inside of the parachute, fold the parachute over in an S shape and tie the jolly logic chute release off to the end of the shock cord. Mine tangled also when I tried to attach it to the parachute line as recommended in the instructions.
It has worked great from 5000ft on a 50" parachute. Bigger I would look at another deployment method.
It has worked great from 5000ft on a 50" parachute. Bigger I would look at another deployment method.
This is what I do. The original photo is from Allen Hall, which I annotated for clarity. I print this out and take a copy with me to the launches to make sure I get it right:
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