Jolly Logic Chute Release and Altimeter Three Systems on L-2 Attempts?

[Tom Zachman]

Bottom line is you need to treat it as carefully as packing the chute, installing the ignitor, etc. etc. Be very consistent about how you do it every single time.

 

[Tom Zachman]

Well said!

 

[FatBoy]

I used a Jolly Logic Chute Release and Jolly Logic Altimeter 3 (along with an Eggfinder Mini locator) on my L2 cert for a flawless flight.

 

[Tom Zachman]

Good to hear. Congratulations on your success.

 

[Ben Martin]

I used a JLCR with motor ejection for my L2. I couldn't physically see the separation, but I did see the successful deployment of the JLCR after a few minutes of drift/free fall. Even without a drogue my rocket drifted a good ways from 4200, I got lucky with where it came down. I enjoy my JLCR so far and I learned the importance of good parachute packing the hard way, damaging my L1 4in Patriot in the process.

 

[Tom Zachman]

Well done on your L-2. You are absolutely correct on the importance of a good tight parachute pack. Thanks for the reply.

 

[lowga]

Congratulations on your L-2.

I often tell people that if the JLCR had been invented prior to the twenty years + of dual deploy using BP charges, it would be the standard. If there were more motors with 18-20 seconds of delay for ejection I think you'd see JLCR used even more often.

Given the scrutiny that the hobby is under, moving away from black powder makes sense long-term.

 

[John Beans]

By the way, as I think we've discussed elsewhere, the decision to have Chute Release turn off after ground test is just a software decision designed to save battery power. For instance, I'm sure there are some people who don't even know how to turn Chute Release off if needed, since it does that automatically all the time.

But if enough people want it to stay on after ground test, that's as simple as commenting out one line of code, and perhaps adding a turn off timer (like 2 hours or so).

 

[lowga]

As the proud (and happy) owner of three Jolly Logic Chute Releases, I'd vote for changing that line of code. I've had one failure of the JLCR on a low power rocket because I forgot to turn it back on after completing the ground test.

Ideally, after a ground test, it would be great if two things happened:

1.) Unit remains in the "ON" state for two hours.
2.) Unit defaults to opening the chute at 500 feet.

This is similar to the default on many altimeters. If you conduct a ground test, and forget to reprogram the device, the chute will open at 500 feet anyway.

 

[BDB]

I agree. I'm the proud owner of two chute releases (though one is currently stuck in a tree). I use them on nearly every flight (including my L2 flight). I haven't ever had a problem like lowga just mentioned, but I'd like the assurance that once it's on, it's on.

 

[Banzai88]

My vote would be to leave it alone.

 

[lowga]

Who are you going to listen to John? A "surface puke" like Tom, or a "bubble head" like me?

Tell you what Tom, if John decides to change the code, I'll buy three new ones, and send you my old ones. That way, all ex-Navy rocket flyers can be happy.

Les Rayburn, N1LF
NRA 81057 Level 2
Former RM1(SS) USN

 

[DavidMcCann]

Further the the expense of drogue chutes, chute blankets as well as the ongoing costs of electric matches, gunpowder, batteries not to mention assembly time, component testing, and proper storage of explosives in a home environment were all part of the financial equation.

All good things to consider. I guess it's easy to forget all the side costs once you get into doing it regularly.

For me, I don't run drouge chutes on most flights.... it's something people debate, it works for me.
Extra chute blankets, I run kevlar shock cords and basically just roast anything in the booster section (no chute, why not?)
Matches, no way around those. looking at $2-8 a flight (ranging from single alt DD to a dual 4-channel bay)
Gunpowder, a one pound can will last a good long while (years) at 2-8gs for an average 54mm-4" rocket flight
Storage...it's less volatile than a can of gas in your garage, so unless you're someone who keeps fuel in a fireproof locker, a can of 4F will sit on a shelf just as inert as rattle can of krylon.
Batteries, I found going lipo and getting a decent charger saved a lot of headaches.

Added all up, I guess it is more than the $80/pop for an altimeter... however when you consider the added benefits, I think it puts DD av bays and a JLCR/alt3 into different categories, and it's less of a cost analysis and more of a "what fits my flight/rocket" choice.

 

[Banzai88]

Who are you going to listen to John? A "surface puke" like Tom, or a "bubble head" like me?

Rarefied air has gotten the better of you. A proper AIRDALE would NEVER self-identify as surface anything!

 

[lowga]

Tom--you should remember. There are really only two types of ships.

1.) Submarines
2.) Targets

Death From Below.

 

[Tom Zachman]

Tom--you should remember. There are really only two types of ships.

1.) Submarines
2.) Targets

Death From Below.

Former proud Air Force officer. Retribution from above! PS. Love the Navy and the sea. Fifty years as a diver with a love for exploring German WW II subs and Imperial Japanese Navy warships, tankers, and freighters.

 

[scott johnson]

I've used the JLCR successfully for over two months now....ten launches with one "failure". I didn't do the "shake test" prior to launch and the chute slipped out of the release at ejection (deployment at 1800' in a 12 mph wind with a 24" chute on a lightweight Star Orbiter makes for a looooong walk!). There is a technique to using them, and it involves following the instructions that come with it. I get razzed by the fellows at the LCO table about it although I have witnessed several "lawn darts" with DD setups. A previous poster summed it up. Increased complexity adds to the chance of failure. As a BAR, I am more interested in relearning building and prep skills forgotten in over 40 years of being away from rocketry (and learning new skills like reloadable motors and reliability!) than being on the cusp of technology. Having said that, I will be launching my first dual deploy test tomorrow, although for the first test it will be motor ejection at apogee, followed by pyro ejection at 400'. Geez Louise, it better work....I have performed enough ground tests with the shop vac in the back yard this week to make the neighbors think I have a bunker full of fireworks!

 

[Tom Zachman]

I've used the JLCR successfully for over two months now....ten launches with one "failure". I didn't do the "shake test" prior to launch and the chute slipped out of the release at ejection (deployment at 1800' in a 12 mph wind with a 24" chute on a lightweight Star Orbiter makes for a looooong walk!). There is a technique to using them, and it involves following the instructions that come with it. I get razzed by the fellows at the LCO table about it although I have witnessed several "lawn darts" with DD setups. A previous poster summed it up. Increased complexity adds to the chance of failure. As a BAR, I am more interested in relearning building and prep skills forgotten in over 40 years of being away from rocketry (and learning new skills like reloadable motors and reliability!) than being on the cusp of technology. Having said that, I will be launching my first dual deploy test tomorrow, although for the first test it will be motor ejection at apogee, followed by pyro ejection at 400'. Geez Louise, it better work....I have performed enough ground tests with the shop vac in the back yard this week to make the neighbors think I have a bunker full of fireworks!

Good luck! Will be following in your footsteps soon. Love a technical challenge as well from a fellow BAR.

 

[solid_fuel]

As the proud (and happy) owner of three Jolly Logic Chute Releases, I'd vote for changing that line of code. I've had one failure of the JLCR on a low power rocket because I forgot to turn it back on after completing the ground test.

Ideally, after a ground test, it would be great if two things happened:

1.) Unit remains in the "ON" state for two hours.
2.) Unit defaults to opening the chute at 500 feet.

This is similar to the default on many altimeters. If you conduct a ground test, and forget to reprogram the device, the chute will open at 500 feet anyway.

I am ok with having it stay on but why default to 500’? Why not have it stay at the altitude it was programmed for before the ground test?
My biggest fear is that I forget to attach it to something on the rocket. A ground test saved my chute release at the last launch as it fell untethered to the ground when the band opened on my ground test.