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Jolly Logic Chute Release

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I spent all day flying rockets in a field that I would normally consider far too small for the Gs I was using.

I cannot recommend this product more highly - worked flawlessly every time, parachute opening at 200 feet. Just a good piece of equipment I wish I had years ago.
 
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o1d_dude

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Agreed.

Did my L2 on a JLCR just for spits and giggles.

Also have done dual deploy in the conventional manner on multiple occasions so no harm no foul.

The JLCR is so much quicker to turn around on multiple flights and you don’t have the expense of multiple altimeters, sleds, batteries, and hardware.

More moolah for MOAR POWR!!
 

Joshua F Thomas

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I was advised to get one for my L1 cert.

Other than "it's great!", what useful advice can current users give? Gotchas? Best practices?
 

o1d_dude

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A few practice flights on G motors to get your chute folding and deployment skills up to snuff would be a good thing if you want to pass on the first cert flight.
 
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o1d_dude

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Most important advice is to make sure it’s turned on. Have seen more failures from people not turning it back on after ground test.
THIS!

Next time I see John Beans I’m going to hit him up for a status beeper in the next iteration of the JLCR.

In the interim I will NOT power down after the the ground test at the launch site. The JLCR will run for hours...maybe days before it discharges...and it has NO auto-shutdown functionality.

I have a Dino Chutes “Remove Before Flight” streamer specifically to remind me to check the status of the JLCR before I walk away from the pad.

From the dinochutes.com website:

C6B7A06E-5ED0-4744-9B06-B5C4A72EB1D0.jpeg
 

SecondRow

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In the interim I will NOT power down after the the ground test at the launch site. The JLCR will run for hours...maybe days before it discharges...and it has NO auto-shutdown
JLCR powers down automatically after ground test, doesn’t it? That’s the cause of a lot of failures. User ground tests just before flight to test parachute setup. JLCR powers down after test. User forgets to turn it back on.
 

MOF410

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I love my JLCR...it will pay for itself in less lost rockets. Altitude settings are nice, can be used for a little hang time to get camera footage, or to keep it close to the pad.

I like that u can fly big on a smaller field and get your rocket back.

It is very reliable, just make sure you turn it on. I always double and triple check that its on. Even interrupted a launch yesterday to double check since it had been so long since it was loaded on the rod (waiting for others to load, etc.).

Battery seems to last forever, so using all day at a launch hasn't been a problem.

The retainer works well too, it always stays right where I tied to it.

Can't give enough props. If u don't have one, get it, use it, and then you will know.

Did I even mention the extra event it adds to a normal launch and recovery? Anticipation as it approaches deployment altitude, then the great moment when the chute pops open, which is awesome to watch at 300-200'..
 

PayLoad

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....Did I even mention the extra event it adds to a normal launch and recovery? Anticipation as it approaches deployment altitude, then the great moment when the chute pops open, which is awesome to watch at 300-200'..
Excellent point - loved it, as it added to the enjoyment of the entire experience
 

Dan Griffing

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I was advised to get one for my L1 cert.

Other than "it's great!", what useful advice can current users give? Gotchas? Best practices?
The one gotcha I noticed was that with an overly aggressive ejection charge, the shock of the nosecone hitting the end of the shock cord is enough to trigger the ChuteRelease.

Another gotcha is having a very long rocket without using a small drogue along with the ChuteRelease with the main.

I’ve seen a very long rocket streamline towards the ground at a high speed, and the shock from the ChuteRelease causing the main chute to open was enough to cause the airframe to zipper.

That said, the ChuteRelease is a great product and I’ve enjoyed using it because its much simpler and lighter than a dual deployment system.

Finally, my advice for an L1 attempt is to keep things as simple as possible.

Launch with a motor that will reach an altitude of 1,000 to 1,500 feet on a large enough field and there’s no need for anything but a main chute and motor ejection with the delay set according to the RockSim simulation advice. This will avoid the possibility of a ChuteRelease failing, for whatever the reason.

Sometimes in the anxiety leading up to an L1 attempt people forget things, such as to properly turn on and arm a ChuteRelease. Then, not only will the L1 attempt be a failure, but the rocket will be destroyed.

Successful rocketry in the early learning phases is often about eliminating unnecessary risks. And many of the coolest things are more risky.
 
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Dan Griffing

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A few practice flights on G motors to get your chute folding and deployment skills up to snuff would be a good thing if you want to pass on the first cert flight.
Folding and packing a chute correctly with a ChuteRelease is quite important.

If the package with its chute, ChuteRelease, Nomex chute protecter and shock cord are even slightly too tight in the airframe, they’ll stick and your rocket will turn into a lawn dart. And this is a very difficult thing to determine.

This happened to me in July after two nearly identical successful launches in the same day with the same configuration and packing with a ChuteRelease.
 

manixFan

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JLCR powers down automatically after ground test, doesn’t it? That’s the cause of a lot of failures. User ground tests just before flight to test parachute setup. JLCR powers down after test. User forgets to turn it back on.
That's been the number one cause of the failures we've had at our launches. I honestly don't understand the logic of it turning off after a test. If it's in test mode it implies that the user has the device in hand and is actively working with it and can turn it off when done testing, rather than having it shut off automatically. It would be great if there was a way to update the firmware to override that behavior.

The other issue we see a lot is it releases but the chute does not open. That's trickier but usually due to how the chute is wrapped and how tight the band was around the bundle. Ground testing is the way to avoid that but chute malfunctions can happen with any type of deployment.

I have a JLCR and have had good luck with it, but others in our club have quit using them altogether.


Tony
 

Dan Griffing

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That's been the number one cause of the failures we've had at our launches. I honestly don't understand the logic of it turning off after a test. If it's in test mode it implies that the user has the device in hand and is actively working with it and can turn it off when done testing, rather than having it shut off automatically. It would be great if there was a way to update the firmware to override that behavior.

The other issue we see a lot is it releases but the chute does not open. That's trickier but usually due to how the chute is wrapped and how tight the band was around the bundle. Ground testing is the way to avoid that but chute malfunctions can happen with any type of deployment.

I have a JLCR and have had good luck with it, but others in our club have quit using them altogether.


Tony
The lesson here is that its really important to know how your equipment works before you get to the launch.

If you’ve practiced enough and have a detailed check list to keep you from forgetting any of the steps, you’ll probably be successful.
 

dwtno

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For those already using a JLCR, what’s the smallest diameter body tube you can use it with? Also, what’s the lowest powered engine you’ve launched with a JLCR aboard?
 

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If you can get things packed absolutely perfect, I'm told it will fit in a 38mm/BT60. But I wouldn't personally try it in anything smaller than a 54mm body tube.

-Hans
 

manixFan

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The lesson here is that its really important to know how your equipment works before you get to the launch.

If you’ve practiced enough and have a detailed check list to keep you from forgetting any of the steps, you’ll probably be successful.
I agree 100%. But if a simple change to the way a device works can greatly improve the odds of success, that seems like an easy choice. I know the designer of the JLCR visits here often, it would be useful to hear his decision making process to have it turn off after a test. I'm sure he has good reasons for why it's been programmed to behave as it does.


Tony
 

dhbarr

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I don't like it in a 38mm, but 2in is pretty great.
 

SecondRow

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I’ve used mine in my Estes STM 012 (BT 60) with an E motor to ~1000 ft. Our LP field is long but thin. 1000 ft usually ends up in the trees. But with the chute release, I get deployment around 200-300 ft, sometimes I’ve gone to 100 ft on windy days.

it’s definitely a snug fit in the BT60, but it is doable. just make sure it moves smoothly in the tube.
 

Dugway

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The biggest advice I have for the JLCR is to chuck the included rubber bands and replace with 100% silicone. I had rubber bands snap several times when just pulling them around the parachute burrito. I haven't had a single failure since switching to silicone bands, they are MUCH stronger, won't rot over time, and grip the 'chute without hanging up when the chute release releases.
 

dwtno

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The biggest advice I have for the JLCR is to chuck the included rubber bands and replace with 100% silicone. I had rubber bands snap several times when just pulling them around the parachute burrito. I haven't had a single failure since switching to silicone bands, they are MUCH stronger, won't rot over time, and grip the 'chute without hanging up when the chute release releases.
Where does one find silicone bands of the proper size?
 

manixFan

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The biggest advice I have for the JLCR is to chuck the included rubber bands and replace with 100% silicone. I had rubber bands snap several times when just pulling them around the parachute burrito. I haven't had a single failure since switching to silicone bands, they are MUCH stronger, won't rot over time, and grip the 'chute without hanging up when the chute release releases.
Hmm, very interesting. That seems to be the other big failure mode - it opens but the rubber band seems 'stuck' to the chute. I advised dusting the chute and band with talcum powder (I use billiard talc) to help ensure release. But the silicone bands definitely seem worth trying. Thanks for the tip.


Tony
 

Dan Griffing

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The biggest advice I have for the JLCR is to chuck the included rubber bands and replace with 100% silicone. I had rubber bands snap several times when just pulling them around the parachute burrito. I haven't had a single failure since switching to silicone bands, they are MUCH stronger, won't rot over time, and grip the 'chute without hanging up when the chute release releases.
Where do you get your silicone bands?
 

Sabrina

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I spent all day flying rockets in a field that I would normally consider far too small for the Gs I was using....
Let me start by saying - I'm not the safety police -or- the Soup Nazi. But I am disappointed. 😞😞😞

My concern is you just admitted to spending an entire day purposefully and knowingly violating the safety code and you seem proud or obliviously or both.

If your jolly rancher (yes I said jolly rancher, I'm just a silly school girl) opens at apogee -:eek::eek::eek: and the rocket drifts into some dry flammable brush 1000 feet from the launch pad.

Here is what could happen:
Big wildfire, lots of acers destroyed, everyone pissed at your irresponsible judgement. (think about the current situation on the west coast)
No soup for you - and no insurance too. Violation of the safety code = claim denied.

Tisk, Tisk, Tisk - You are setting a bad example for all the other kids.

G motor is 1000 feet minimum on the shortest side of the launch site.
More than just a suggestion, these safety codes are STATE LAW in most (not all) of the USA. - Pretty sure PA is included.


nar.PNG
 
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QFactor

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Hmm, very interesting. That seems to be the other big failure mode - it opens but the rubber band seems 'stuck' to the chute. I advised dusting the chute and band with talcum powder (I use billiard talc) to help ensure release. But the silicone bands definitely seem worth trying. Thanks for the tip.


Tony
Take a look at hair bands. Been using them for a couple years. Inexpensive - buy at the Dollar Store, Walmart, etc. Come in assorted sizes. Last longer. Use a twist tie to pull the band thru the hole on the Jolly Logic.

IMG_7794.JPGIMG_7803.JPG
 

PayLoad

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Let me start by saying - I'm not the safety police -or- the Soup Nazi. But I am disappointed. 😞😞😞

My concern is you just admitted to spending an entire day purposefully and knowingly violating the safety code and you seem proud or obliviously or both.

If your jolly rancher (yes I said jolly rancher, I'm just a silly school girl) opens at apogee -:eek::eek::eek: and the rocket drifts into some dry flammable brush 1000 feet from the launch pad.

Here is what could happen:
Big wildfire, lots of acers destroyed, everyone pissed at your irresponsible judgement. (think about the current situation on the west coast)
No soup for you - and no insurance too. Violation of the safety code = claim denied.

Tisk, Tisk, Tisk - You are setting a bad example for all the other kids.

G motor is 1000 feet minimum on the shortest side of the launch site.
More than just a suggestion, these safety codes are STATE LAW in most (not all) of the USA. - Pretty sure PA is included.


View attachment 432361
Dad?

You forgot that I could poke someone's eye out.
 

CaptHaywire

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Take a look at hair bands. Been using them for a couple years. Inexpensive - buy at the Dollar Store, Walmart, etc. Come in assorted sizes. Last longer. Use a twist tie to pull the band thru the hole on the Jolly Logic.

View attachment 432382View attachment 432383
Hair bands don't stick to the parachute either. I have had very good luck with them also.
 

Bill Heath

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If you can get things packed absolutely perfect, I'm told it will fit in a 38mm/BT60. But I wouldn't personally try it in anything smaller than a 54mm body tube.

-Hans
It easily fits in a BT60 tube. I see more used in small airframes than large. It was designed for small rockets.
 

QFactor

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I was advised to get one for my L1 cert.

Other than "it's great!", what useful advice can current users give? Gotchas? Best practices?
Good chute packing technique is important. Chute can pushout from under the band during the descent if not wrapped well. Don't tether the JLCR to a chute shroud line - tether it to the harness. And if you use it a lot - replace the supplied tether with a slightly heavier kevlar tether on the JLCR. You can see pictures of my tether up in post #26.
 

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