Sneak Peak: Jolly Logic's Easy Dual Deployment

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I made 6 flights with the Chute Release yesterday, and had 4 that were completely successful. One that wasn't successful was no fault of the CR, as the nose cone never seperated and came in ballistic. CR survived without issue, and appeared to have released on the way in. On the other flight, the parachute deployed at apogee. It must have slipped the band on the CR at ejection, despite passing ground tests. But the way that chute was wrapped (and I was experimenting with it a little) didn't load the band as tightly as the previous flights, so, lesson learned.

One other note - I went through several of the included bands in course of the day. It seemed like every other flight, the band came back with a cut from something. I wonder if they're being caught by the edge of split-ring on the release pin.
 
EXPjawa said:
I made 6 flights with the Chute Release yesterday, and had 4 that were completely successful. One that wasn't successful was no fault of the CR, as the nose cone never seperated and came in ballistic. CR survived without issue, and appeared to have released on the way in. On the other flight, the parachute deployed at apogee. It must have slipped the band on the CR at ejection, despite passing ground tests. But the way that chute was wrapped (and I was experimenting with it a little) didn't load the band as tightly as the previous flights, so, lesson learned.

One other note - I went through several of the included bands in course of the day. It seemed like every other flight, the band came back with a cut from something. I wonder if they're being caught by the edge of split-ring on the release pin.
Click to expand...

I've used the same band on each of 6 or 7 flights so far.. band is fine. I used the larger band.
 
I've been using the same small band since I got mine, no degradation at all so far on it. About 2 dozen flights in sizes up to 4"/H rockets with chutes up to 36" elliptical. Haven't had a failure yet.

Having flown it 3 more times yesterday at Bayboro, and based on the flight line buzz, likely a few more will be sold soon! :)
 
I only used the large band on one flight, since I really only have one rocket with a large enough parachute to need it. With the smaller band size, I saw several that apparently got nicked or cut on the edge after being used, so when I stretched them the next time, they got narrow in the area that was partially cut. I'm not sure what the cause is, but obviously, I didn't want to reuse that band.
 
You might want to wrap the split area of the ring with a thin strip of electrical tape to smooth it over and see if that changes your results.
 
There are some sharp corners on the ring. I wish there weren't. I'd advise turning the ring so that the bands don't contact the sharp corners. Hopefully we can find some rings in the future that aren't as sharp...
 
I've has a half dozen flights on mine with the same band. So far, no issues. I am loving it!
 
Hello Mr. Beans-

I hope this note finds you well. I wanted to let you know about two flights I did last weekend.

I have a scratch built 5.5" rocket that I flew on a J540-R and a K535-W. On both flights, I set up for standard dual deploy.

On the J540 flight, I flew without a drogue as I usually do when the winds are a little high. As the rocket approached 700 feet (where i set the main), the payload just happened to point down and in such a way that as the chute came out......the lower shock cord came down and fowled the main chute. There was no damage but it made for a messy flight.

On the second flight with the K535. I put the chute release on the lower shock cord and used it to bind a 30" drogue. I wrapped the whole bundle like I did on my photos on your website. I set the chute release to let the drogue go at 1000 feet. The rocket scooted nicely to 4,535 feet.

As planned, the rocket tumbled after the apogee event. At 1000 feet, the drogue was let go and opened nicely.....it then oriented the payload above the booster just in time for the main to come out at 700 feet.

This gave me the bennefits of going without a drogue and thus have even less drift.....WITHOUT the danger of a fouled main. In fact, by placing the CR near the avionics bay (properly protected of course), the drogue made sure that when my main fired, it was clear of the booster and cord.

I will now never fly my bigger high power without it (the CR). Thanks again for a great product.

BTW: The CR I still use is your old tester unit! YEP! it is still going strong!

Regards,
Andrew K.

TRA L2
 
AKVP said:
I put the chute release on the lower shock cord and used it to bind a 30" drogue. I wrapped the whole bundle like I did on my photos on your website. I set the chute release to let the drogue go at 1000 feet. The rocket scooted nicely to 4,535 feet.

As planned, the rocket tumbled after the apogee event. At 1000 feet, the drogue was let go and opened nicely.....it then oriented the payload above the booster just in time for the main to come out at 700 feet.

This gave me the bennefits of going without a drogue and thus have even less drift.....WITHOUT the danger of a fouled main. In fact, by placing the CR near the avionics bay (properly protected of course), the drogue made sure that when my main fired, it was clear of the booster and cord.

I will now never fly my bigger high power without it (the CR). Thanks again for a great product.

BTW: The CR I still use is your old tester unit! YEP! it is still going strong!

Regards,
Andrew K.
Click to expand...

So, you just used one Chute Release wrapped around both a drogue and a chute? Or two Chute Releases.

Thanks for the kind words about Chute Release.
 
Mr. Beans-

Nope....I simply set the rocket up for standard dual reploy with electronics and two charges. Apogee charge and main. The ONLY thing I did different, is I bound the 30" drogue chute until 1000 feet. The rocket fell "drogueless" until 1000 feet. When the drogue was released, the whole recovery set up "stretched out" and "lined up" so when the main fired, there was no chance of it interfering with the lower shock cord and booster.

Again, the timing of the drogue being released, served to make sure the rocket was oriented in such a way as to prevent random fouling of the recovery harness that sometimes happens when a dual deploy rocket is flown without a drogue. I hope this helps.
 
So.... via CR, turned dual deploy into "triple deploy" - drogueless (apogee charge), then the drogue (via CR) then the main (main charge). Cool!
 
Someone asked about very large chutes, like a 12 foot diameter one. Here's my advice.

That's a larger chute that I think any has tested before, so you'd be a bit of a pioneer. No reason you couldn't make it work well, but I don't have a "tried and true" way that's been tested. I would start with a longer band, perhaps one about 8" long (16" of rubber in a loop). You'd need to practice wrapping it around your folded chute (shrouds inside, see our video) multiple times, and doing ground tests until you're sure it will quickly unwrap. The "smoother" and "tighter" the bundle was before you wrapped it, the better it would probably work. The main thing to worry about is the chute being so soft and squishy that the rubber band gets caught and pinched and gets trapped after the pin is released. I've seen this happen even on smaller 30" chutes.

If you use a fire blanket (recommended), put it OUTSIDE of the chute and release, and tether the fire blanket *away* from the chute bundle closer to the fin section so that when the shock cord stretches out it will be pulled away from the chute bundle and Chute Release (both of which it protected during ejection). So you'll end up with a straight line "stack" as it falls with drogue at the top, then chute bundle, then nose cone then fire blanket then fuselage. There are variations on that that are okay, but the care you need to take is that stuff stays separated, not twisted (use swivels), and that you realize that anything "flapping around" will want to wrap around anything it can reach.

And during ground tests, you want your chute to always spring open. Be wary of tests where the band seems to be getting pinched and caught in your chute. You want the thing to spring open. Consider z-folds and maybe one outside roll vs. just purely rolling. Experiment until you can find a tight bundle that feels like it will stand up to a 50 mph wind, but that "pops open" when Chute Release triggers.

We'll be developing and commercializing band alternatives, but for now a little experimentation is in order. And remember, if you're not sure how quickly your bundle will unfurl and inflate, start with a high (> 500') setting.
 
John Beans said:
Someone asked about very large chutes, like a 12 foot diameter one. Here's my advice.

That's a larger chute that I think any has tested before, so you'd be a bit of a pioneer. No reason you couldn't make it work well, but I don't have a "tried and true" way that's been tested. I would start with a longer band, perhaps one about 8" long (16" of rubber in a loop). You'd need to practice wrapping it around your folded chute (shrouds inside, see our video) multiple times, and doing ground tests until you're sure it will quickly unwrap. The "smoother" and "tighter" the bundle was before you wrapped it, the better it would probably work. The main thing to worry about is the chute being so soft and squishy that the rubber band gets caught and pinched and gets trapped after the pin is released. I've seen this happen even on smaller 30" chutes.

If you use a fire blanket (recommended), put it OUTSIDE of the chute and release, and tether the fire blanket *away* from the chute bundle closer to the fin section so that when the shock cord stretches out it will be pulled away from the chute bundle and Chute Release (both of which it protected during ejection). So you'll end up with a straight line "stack" as it falls with drogue at the top, then chute bundle, then nose cone then fire blanket then fuselage. There are variations on that that are okay, but the care you need to take is that stuff stays separated, not twisted (use swivels), and that you realize that anything "flapping around" will want to wrap around anything it can reach.

And during ground tests, you want your chute to always spring open. Be wary of tests where the band seems to be getting pinched and caught in your chute. You want the thing to spring open. Consider z-folds and maybe one outside roll vs. just purely rolling. Experiment until you can find a tight bundle that feels like it will stand up to a 50 mph wind, but that "pops open" when Chute Release triggers.

We'll be developing and commercializing band alternatives, but for now a little experimentation is in order. And remember, if you're not sure how quickly your bundle will unfurl and inflate, start with a high (> 500') setting.
Click to expand...

Thanks for the info! I can't wait to fly some larger chutes soon...

Just curious, any suggestions for using a Nomex blanket when the rocket has charges at both ends of the recovery bay? I'm going to try a CR in a 3" fiberglass rocket with a nose cone mounted (altimeter controlled) charge, but it will have a motor backup on the other end of the recovery bay.

On previous CR flights I've stuffed the Nomex to the bottom of the recovery bay, but that's with motor deploy only. On normal non CR flights where I run charges in the configuration above I quick link the Nomex to the chute quick link, and use a bundle folding method to protect all sides of the chute, but it sounds like that could interfere with the CR.

Any suggestions? My plan had been to use the quick link/bundle method on the flight I mentioned (with a second small nomex bundle for a drogue chute). The idea is that the charge (either one) fires, nose cone pulls both bundled chutes out (with the drogue fully unfolding and opening), and then the main chute opens when the CR opens. It seems like this would still work if the nomex for the main was tied farther down the shock cord, and might help prevent tangling.

Thanks!
-SC
 
Last edited:
SCrocketfan said:
Thanks for the info! I can't wait to fly some larger chutes soon...

Just curious, any suggestions for using a Nomex blanket when the rocket has charges at both ends of the recovery bay? I'm going to try a CR in a 3" fiberglass rocket with a nose cone mounted (altimeter controlled) charge, but it will have a motor backup on the other end of the recovery bay.

On previous CR flights I've stuffed the Nomex to the bottom of the recovery bay, but that's with motor deploy only. On normal non CR flights where I run charges in the configuration above I quick link the Nomex to the chute quick link, and use a bundle folding method to protect all sides of the chute, but it sounds like that could interfere with the CR.

Any suggestions? My plan had been to use the quick link/bundle method on the flight I mentioned (with a second small nomex bundle for a drogue chute). The idea is that the charge (either one) fires, nose cone pulls both bundled chutes out (with the drogue fully unfolding and opening), and then the main chute opens when the CR opens. It seems like this would still work if the nomex for the main was tied farther down the shock cord, and might help prevent tangling.

Thanks!
-SC
Click to expand...

Two blankets, maybe?
 
John Beans said:
Two blankets, maybe?
Click to expand...

As in one on each side of the recovery train? That might look something like this, with the top of the rocket on the left:

(nose cone+charge) [nomex] (drogue) (Main+CR) [nomex] (motor charge)

My plan was something like this-not sure if this is what you meant:

(nose cone+charge) (drogue, bundled in separate nomex) (Main+CR, bundled in separate nomex) (motor charge)

Either way, seems like it could work quite well. I might have to try both, thanks for the idea!
 
SCrocketfan said:
As in one on each side of the recovery train? That might look something like this, with the top of the rocket on the left:

(nose cone+charge) [nomex] (drogue) (Main+CR) [nomex] (motor charge)

My plan was something like this-not sure if this is what you meant:

(nose cone+charge) (drogue, bundled in separate nomex) (Main+CR, bundled in separate nomex) (motor charge)

Either way, seems like it could work quite well. I might have to try both, thanks for the idea!
Click to expand...

Benno, you are a *far* better rocketeer than I am, so trust your instincts/experience and let us all know how it goes.
 
John Beans said:
Benno, you are a *far* better rocketeer than I am, so trust your instincts/experience and let us all know how it goes.
Click to expand...

Wow, thanks! I will definitely let everyone know how the next set of flights goes. I have a few ideas on possible CR setups, can't wait for Dairy Aire to run some test flights.
 
Has anyone used the chute release for high altitude flights (at least by East Coast standards)? I'm thinking about buying one for use in my CF Mongoose 54. With the right engine, it could blow past 20k ft. (Other technicalities: I first need to earn L2 certification and then find a field with a high enough waiver. But that shouldn't stop me from dreaming, right?)
 
BDB said:
Has anyone used the chute release for high altitude flights (at least by East Coast standards)? I'm thinking about buying one for use in my CF Mongoose 54. With the right engine, it could blow past 20k ft. (Other technicalities: I first need to earn L2 certification and then find a field with a high enough waiver. But that shouldn't stop me from dreaming, right?)
Click to expand...

I did a flight last weekend with 54 mm rocket. Launched on a K300 and probably went close to 30K. Unfortunately, the gps browned out and restarted at about 25K on the way down. GPS-based descent velocities in the graph. The rocket drifted a little under a mile coming down from 5 miles.

Jim

Descent.png
 
JimJarvis50 said:
I did a flight last weekend with 54 mm rocket. Launched on a K300 and probably went close to 30K. Unfortunately, the gps browned out and restarted at about 25K on the way down. GPS-based descent velocities in the graph. The rocket drifted a little under a mile coming down from 5 miles.

Jim
Click to expand...

With Chute Release? More details!
 
JimJarvis50 said:
I did a flight last weekend with 54 mm rocket. Launched on a K300 and probably went close to 30K. Unfortunately, the gps browned out and restarted at about 25K on the way down. GPS-based descent velocities in the graph. The rocket drifted a little under a mile coming down from 5 miles.

Jim
Click to expand...
Jim,

If you used a CR it would be great if you did a write up on it. I am planning on doing the same thing at BALLS this year with a 54mm Mongoose on a CTI Pro54 L265 and would sure like to hear your experience.

Thanks,


Tony
 
Last edited:
John Beans said:
With Chute Release? More details!
Click to expand...

Well, you did say it would work! I just did it as instructed. Had a harness from the rocket to the cone and a separate harness - maybe 3 feet long - from the cone to the bundled chute. It was a 30" chute folded three times with one of the longer bands. The rocket went off at a bit of an angle, ultimately landing about 2.5 miles away. I suspect it was a pretty fast apogee event so it was good that the chute stayed bundled through that. I believe I set the release at 900 or 1000 feet. That's about it - piece of cake.

I had the deployment charge attached to the cone with some nomex between the charge and the chute/CR. I think the charge being attached to the cone is why the gps browned out.

Jim

IMG_0784.jpg
 
JimJarvis50 said:
Well, you did say it would work! I just did it as instructed. Had a harness from the rocket to the cone and a separate harness - maybe 3 feet long - from the cone to the bundled chute. It was a 30" chute folded three times with one of the longer bands. The rocket went off at a bit of an angle, ultimately landing about 2.5 miles away. I suspect it was a pretty fast apogee event so it was good that the chute stayed bundled through that. I believe I set the release at 900 or 1000 feet. That's about it - piece of cake....
Click to expand...
Jim,

Thanks for that info - really great to hear it worked well. That's exactly what I am planning on - no separate payload bay dual deployment.

That is a nice looking rocket! It will be interesting to see what kind of altitude I can get from the L265. I flew it at BALLS last year and it is a great motor - nearly a full 10 second burn.


Tony
 
Based on Jim's experience, it sounds like it might be better to friction fit the casing and use motor deployment, or is that living too dangerously?
 
BDB said:
Based on Jim's experience, it sounds like it might be better to friction fit the casing and use motor deployment, or is that living too dangerously?
Click to expand...
Hmm, I'm not sure what you mean by that. I don't see anything in Jim's posts about motor retention or motor deployment. The motor I plan to use is plugged so it requires electronic deployment. And for high altitude flights the coast time often exceeds the max available delay anyway so motor ejection is not an option even if available.


Tony
 

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