Nathan
☢
- Joined
- Apr 19, 2012
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- 2,226
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Since the JLCR came out several years ago I have bought four of them and have two left. But I don't plan to use them anymore because I have had two crashes caused by JLCR related deployment failures. In both cases it was on my single-deploy 15 lb Upscale Onyx using a 48 inch FruityChute burrito wrapped in a chute protector, and the JLCR set to release at 500 ft.
In one case the JCLR and rubber band were wrapped around the outside of the chute protector. It appeared that the JLCR didn't release and the rocket landed hard, cracking a fin joint. When we recovered the rocket we found that the JLCR had released but the chute was still in the chute protector, not entangled at all. It was not clear whether the JLCR opened late or if the chute just didn't open for some undetermined reason.
After that failure I tried instead wrapping the rubber band around the chute inside of the chute protector. The idea was that it would allow the chute protector more time to unwrap from the chute during freefall before the JLCR releases. But in that case the chute became untangled when the JLCR released. When we recovered the rocket the chute was entangled in both the tether and recovery harness. Was not able to determine what happened first because there was spinning during the tangled descent so everything got all twisted together.
I was not able to determine the exact cause of either of these failures. But my failure rate with the JLCR has been higher than with traditional dual deploy. In my experience, traditional dual-deploy is much more reliable than the JLCR, especially with redundant dual-deploy. I have since repaired my Upscale Onyx but I have now bought a new nose cone and converted it to head-end dual deploy. I might still use a JLCR to release a drogue at 1000 ft but I will no longer be using the JLCR to deploy a main chute.
For the two JLCRs that I lost, one was a flight in which the tether broke. That was determined to be because it was packed in such a way that at deployment there was tension on the tether before there was tension on the recovery harness, causing the thin tether to break. The other JLCR was lost along with the rocket when it landed in a pond.
In one case the JCLR and rubber band were wrapped around the outside of the chute protector. It appeared that the JLCR didn't release and the rocket landed hard, cracking a fin joint. When we recovered the rocket we found that the JLCR had released but the chute was still in the chute protector, not entangled at all. It was not clear whether the JLCR opened late or if the chute just didn't open for some undetermined reason.
After that failure I tried instead wrapping the rubber band around the chute inside of the chute protector. The idea was that it would allow the chute protector more time to unwrap from the chute during freefall before the JLCR releases. But in that case the chute became untangled when the JLCR released. When we recovered the rocket the chute was entangled in both the tether and recovery harness. Was not able to determine what happened first because there was spinning during the tangled descent so everything got all twisted together.
I was not able to determine the exact cause of either of these failures. But my failure rate with the JLCR has been higher than with traditional dual deploy. In my experience, traditional dual-deploy is much more reliable than the JLCR, especially with redundant dual-deploy. I have since repaired my Upscale Onyx but I have now bought a new nose cone and converted it to head-end dual deploy. I might still use a JLCR to release a drogue at 1000 ft but I will no longer be using the JLCR to deploy a main chute.
For the two JLCRs that I lost, one was a flight in which the tether broke. That was determined to be because it was packed in such a way that at deployment there was tension on the tether before there was tension on the recovery harness, causing the thin tether to break. The other JLCR was lost along with the rocket when it landed in a pond.
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