JL Chute Release - latest improvements?

[billdz]

I've been a fan of the JLCR for over 6 years. I have 4 of them and rarely use traditional dual deploy these days. Just wondering if anyone had recently come up with any ideas for improving the device. I searched this forum but did not see anything other than the 2 big older ideas that I have already successfully tried:
* replace the rubber band with a woman's hair tie (the ties have never broken, the bands sometimes do break)
* daisy chain 2 JLCRs for extra security if one fails (only works with larger rockets).

My JLCR success rate is over 85% (not counting operator errors, such as failure to turn the device on), but since the consequence of a failure can be quite severe, I'm always looking for ways to make the JLCR even better.

 

[KenECoyote]

I believe I read about this in a NAR magazine article and it seems to work well for me (so far):

"Plastic clamshell packaging spring"


I hot glued it on.

 

[KenECoyote]

I believe I read about this in a NAR magazine article and it seems to work well for me (so far):

"Plastic clamshell packaging spring"
View attachment 580205

I hot glued it on.

I should add that I had one instance where the JLCR was released, but the rubber band had somehow incredibly still held the chute bunched together (never seen something like that) and I feel this plastic spring would help prevent that.

 

[billdz]

I should add that I had one instance where the JLCR was released, but the rubber band had somehow incredibly still held the chute bunched together (never seen something like that) and I feel this plastic spring would help prevent that.

Thanks for the reply. Sounds interesting, could you point me to further details about the "clamshell"? I could not find anything in the NAR magazine.

 

[Pinetree]

I've been debating getting one, but the community seems to be divided into two camps.. "the greatest thing to happen to the hobby", and "just another way to crash your rocket".

They seem simple enough.. is it operator error that causes failures? Are the people using them successfully too busy flying their rockets to go online to express how much they like the things?

In other words.. somebody talk me into (or out of) buying one.

Full Disclosure: I'm new at this, haven't even made a L1 cert launch yet, and apparently have WAY too much time on my hands.

Thanks.

 

[MidOH]

Well, you have to fold your chute wrong. Lines inside neatly, then roll up each end into a super tight ''C'' shape. Rubber band must go on the round side of the "C'' shape. Release goes on the open side of the ''C''. Firm, thick chutes, like Loc chutes, fold up nicer into that ''C'' shape. Soft expensive chutes can be too plush, or fold up too small, and suck the rubber band in.

Even more stupidity: I run the shock cord in the center of the ''C''. So everything is a nice tight line as the rocket tumbles down.

Elastic does improve the machine. But makes it more finicky to swap from rocket to rocket.

Once you get the hang of it, it's a priceless tool, for BT80 or larger, simple rockets.

 

[KenECoyote]

Thanks for the reply. Sounds interesting, could you point me to further details about the "clamshell"? I could not find anything in the NAR magazine.

Clamshell refers to common clear plastic packaging that some small products come in (ex. Aerotech 29mm dms twin packs, but a bit thicker is better imho).


Basically it's something like lexan that has some springyness to act like a spring push away for the device.

 

[manixFan]

I've had one for quite a while and have not had a failure, so I am a fan for the most part. I make my own 'rubber bands' using elastic shock cord from mid-power kits. (The fabric coated stuff.) That allows me to size the band exactly for the chute bundle.

But I think it's likely the most common failure mode is from flyers testing their setup and then forgetting to turn it back on after rigging it for an actual flight. If it beeped occasionally like an altimeter when powered on, I think that would be a huge help. But I understand adding that ability would increase the size and cost.

Packing a chute reliably is a challenge even without a JLCR – we've all seen plenty of tangled chutes, balled up chute protectors, open quicklinks, etc., to realize it's hard enough without adding another layer of complexity on top of it. But the JLCR does serve an important function, so I feel it's worth the risk.

Practice, Practice, Practice seems to be the key, at least for me. That and finding out what caused a failed recovery from other flyers to help inform my own procedures.


Tony

 

[KenECoyote]

I've been debating getting one, but the community seems to be divided into two camps.. "the greatest thing to happen to the hobby", and "just another way to crash your rocket".

They seem simple enough.. is it operator error that causes failures? Are the people using them successfully too busy flying their rockets to go online to express how much they like the things?

In other words.. somebody talk me into (or out of) buying one.

Full Disclosure: I'm new at this, haven't even made a L1 cert launch yet, and apparently have WAY too much time on my hands.

Thanks.

Common mistakes (may have repeats from above):

• Forgetting to attach it to a line and it free falls away lost.
• Not testing it first (that the bundle doesn't release with yanking/bouncing, but does when JLCR set to an open test).
• Forgetting to turn it on
• Not charged/low charge.
• Pin may be worn and doesn't hold lock
• Releases too early/late (variety of factors).

Probably a few more I'm forgetting.

 

[Sparkyflyer14]

Make sure its not pushing against anything that will hit the power button on takeoff. I've had it happen multiple times. I will have to try the clamshell thing cause I've had that happen.

 

[BEC]

I have done the first and the third things in @KenECoyote's list. I'm also guilty of the second one on his list.

 

[DigBaddy]

Waterproofing would be cool.

 

[Joel Shepherd]

I’ve had pretty good success with it, always with cloth chutes. Actually there is a lot of stuff I’d fly a lot less without it: I’m pretty sure the odds of losing a rocket to drift after a chute inflates at apogee is much higher than the odds of a JLCR failure or severe damage on landing. As with so many things in this hobby, find a routine and stick with it. For me, that includes turning the chute release on last thing before packing the recovery system. Every time.

 

[4regt4]

I like that the delay before opening allows the recovery gear to stretch out linearly before the chute opens. A friend took a very good video of my L1 cert flight. He had zoomed in very tight, catching the deployment in great detail. Ejection occurred immediately after apogee. But I noticed that for those first fractions of a second, the body, chute, nose cone and the shock cord are in a bit of chaos. Having a few seconds of free fall allowed the cone, chute bundle, and body tube to align themselves in a more or less stable configuration vertically. Then the chute opened, perfect flight. Without a JLCR, the chute would have tried to open while things were flailing about, possibly causing something to get tangled.

Hans.

Edit: The above explanation was a bit convoluted. What I'm trying to say is that I think it's helpful to separate the chute opening event from the ejection event.

 

[Banzai88]

... I think it's helpful to separate the chute opening event from the ejection event.

For most of high power, that's done with parachute folding technique and burrito wrap methodology. Not uncommon to see falls of 50-100 feet in the altimeter data before parachute inflation and a decrease in descent speed.

 

[teepot]

I like the JLCR. Have two. Don't like flying without it. Yes I have had failures. Mostly from my mistakes. And a couple that have left me scratching my head. As in, why didn't the chute inflate. I have had a couple that the chute didn't inflate on the way down. I get to the rocket and the chute is still folded on the ground and the CR released the pin. Sometimes even when things go right bad things happen. I use silicone bands in place of the rubber bands.

 

[OverTheTop]

Apparently there is also a failure mode where the sharp end of the ring can catch on something and not release. A piece of tape around the ends if the ring should fix that mode of failure.

 

[Buckeye]

* daisy chain 2 JLCRs for extra security if one fails (only works with larger rockets).

LOL! Typical TRF approach. "Must always have redundant electronic gadgets even though they are the most reliable part of the system!"

Redundancy for what? To keep the chute bundled, or unbundled? Seems like former makes more sense, since chutes can shake loose from the rubber band. If the latter, it is a pricey, and totally unnecessary approach.

 

[tfish]

There's a hack on FB..NAR showing a JLCR firing an ematch..below is only a photo..


Tony

 

[Handeman]

There's a hack on FB..NAR showing a JLCR firing an ematch..below is only a photo..
View attachment 580484

Tony

I can understand that someone would create the hack (because it can be done?), but I can't understand why? You can get DD altimeters for half the price of a JLCR that are designed to fire ematches.

 

[KenECoyote]

I like the JLCR. Have two. Don't like flying without it. Yes I have had failures. Mostly from my mistakes. And a couple that have left me scratching my head. As in, why didn't the chute inflate. I have had a couple that the chute didn't inflate on the way down. I get to the rocket and the chute is still folded on the ground and the CR released the pin. Sometimes even when things go right bad things happen. I use silicone bands in place of the rubber bands.

Which silicone bands do you use?

 

[OverTheTop]

Redundancy for what? To keep the chute bundled, or unbundled? Seems like former makes more sense, since chutes can shake loose from the rubber band. If the latter, it is a pricey, and totally unnecessary approach.

There was a statement upthread that the JLCR was working 85% of the time for someone, if they didn't include where they had misused it unintentionally. Some people really don't want their expensive HPR rockets coming in and becoming flying fenceposts. That can hurt financially, timewise (build time etc) and is also a safety hazard. For HPR an extra chute release isn't that much of a stretch financially.

 

[momo2]

Thanks for the reply. Sounds interesting, could you point me to further details about the "clamshell"? I could not find anything in the NAR magazine.

I've been a fan of the JLCR for over 6 years. I have 4 of them and rarely use traditional dual deploy these days. Just wondering if anyone had recently come up with any ideas for improving the device. I searched this forum but did not see anything other than the 2 big older ideas that I have already successfully tried:
* replace the rubber band with a woman's hair tie (the ties have never broken, the bands sometimes do break)
* daisy chain 2 JLCRs for extra security if one fails (only works with larger rockets).

My JLCR success rate is over 85% (not counting operator errors, such as failure to turn the device on), but since the consequence of a failure can be quite severe, I'm always looking for ways to make the JLCR even better.

Billdz: There is a Sport Rocketry article about an invention called "The KICKer" (November/December, 2022). It's about faster and more reliable chute inflation when using the CR. Check it out.

 

[billdz]

Billdz: There is a Sport Rocketry article about an invention called "The KICKer" (November/December, 2022). It's about faster and more reliable chute inflation when using the CR. Check it out.

Thanks, I'll try that!

 

[Buckeye]

There was a statement upthread that the JLCR was working 85% of the time for someone, if they didn't include where they had misused it unintentionally. Some people really don't want their expensive HPR rockets coming in and becoming flying fenceposts. That can hurt financially, timewise (build time etc) and is also a safety hazard. For HPR an extra chute release isn't that much of a stretch financially.

So, you are suggesting that the JLCR by itself can have a 15% failure rate? Impossible. Beans would be out of business if that was the case.

Failure for the JLCR means that it doesn't hold the pin and then release the pin at the prescribed altitude. Everything else is user error, like it or not. If the rubber band remains bound up or the chute fails to unfurl, that's on you, not the device. Frankly, these are the seemingly random pitfalls of servo release/cable cutter/wire melter methods that lead to more mishaps than traditional pyro deployment of parachutes.

 

[OverTheTop]

So, you are suggesting that the JLCR by itself can have a 15% failure rate? Impossible. Beans would be out of business if that was the case.

I did not suggest it, somebody else did upthread, based on their experience.

Frankly, these are the seemingly random pitfalls of servo release/cable cutter/wire melter methods that lead to more mishaps than traditional pyro deployment of parachutes.

So you are saying this is normal. If so then redundancy is an improvement in the system. You can't argue for no redundancy when you admit there are shortfalls in the outcome. Well maybe you can, but it doesn't make sense.

I don't use one of these so I have no bias either way about the device. I do have a bias towards redundancy to make flights safer.

 

[Handeman]

I did not suggest it, somebody else did upthread, based on their experience.

So you are saying this is normal. If so then redundancy is an improvement in the system. You can't argue for no redundancy when you admit there are shortfalls in the outcome. Well maybe you can, but it doesn't make sense.

I don't use one of these so I have no bias either way about the device. I do have a bias towards redundancy to make flights safer.

I tend to side with @Buckeye on this. If the electronics are reliable, then it is the users responsibility to make sure the rest of the system is as reliable.

If you have a 99.99% reliable device and you only get 85% reliable deployments, adding another 99.99% reliable device to the system is NOT addressing the 14.99% unreliable operation induced by the user.

 

[DragonRocketry]

I can understand that someone would create the hack (because it can be done?), but I can't understand why? You can get DD altimeters for half the price of a JLCR that are designed to fire ematches.

Use a cable cutter where you have no room for an ebay.

 

[Handeman]

Use a cable cutter where you have no room for an ebay.

Don't you still need a altimeter to use a cable cutter? The JLCR already acts in the same way as a cable cutter so no need for the ematch from either a JLCR or altimeter. Still confused why you would rig a JLCR to use an ematch.

 

[KenECoyote]

FWIW I asked one of the club officers for what they feel the failure rate is based on his experience and he answered a shockingly high number and I didn't think he was joking.

I was asking for a baseline since I wanted to use it more this season.

Of note is that I have 3 and one of them I have to send in for repair. It was the one I grabbed the night before our first launch and in testing, the pin was pulling out by itself (wasn't holding securely). I saw that the retaining bolt in the device wasn't extending out enough. This was a new surprise to me and good thing I was testing it before use.

However, in my past experience Jolly Logic has had fantastic support and servicing... top notch.