Sneak Peak: Jolly Logic's Easy Dual Deployment

[kevinkal]

I almost got to try out my new chute release today at Moffett.. but the launch line closed before I made it through. =[

I did get my kids and wife one launch each. Unfortunately, It turned out that I had my chute release installed in the wrong rocket today.. An E9-4 took my Big Daddy to about 900 Ft today, but for some reason the wind switched west just as it was launched and the wind continued just long enough to put it over the wrong area. it got blown into the fenced off area next to hanger 1. That wasn't the bad part... the ugly part happened when the wind drug it by the parachute all the way to the south end of the fence.. hundreds of yards.. I waited with Dave to get Base Ops to help retrieve it well after the launch ended. Thanks again Dave. It sustained lots of drag damage.. sanding about 1/4" of balsa off the sides of all 4 fins, sanded half moons in 4 sides of the front body tube, and the nose cone looks like it went through asteroids due to dragging on the concrete. A chute release would have prevented the whole mess. It won't look the same, but it will fly again.

 

[wighty44]

At BARC's March 19th launch 2 members had 3 CR flights. The heaviest rocket was a Madcow Sea Wolf at 7+ lbs with a CTI I255, 48" Cross-Fire Chute, CR set at 300'. A flawless chute deployment.

Only one of the other 2 use of CR did not work properly - chute deployed near apogee. It was felt by the user that perhaps there was insufficient rubber band tension and the chute was pulled out of the CR device - user error.

 

[ksaves2]

At BARC's March 19th launch 2 members had 3 CR flights. The heaviest rocket was a Madcow Sea Wolf at 7+ lbs with a CTI I255, 48" Cross-Fire Chute, CR set at 300'. A flawless chute deployment.

Only one of the other 2 use of CR did not work properly - chute deployed near apogee. It was felt by the user that perhaps there was insufficient rubber band tension and the chute was pulled out of the CR device - user error.

Been noticing folks have been doing some pretty low chute releases and this is my take on it I offer up for criticism. If one is going to be putting something up that is going to be out of sight for many seconds, it might be more prudent to set a higher chute release as opposed to one down low. Why? If the winds aloft are totally different than the prevailing ground wind direction, a low deployment would lead to a greatly decreased "hang time" and one might not be able to do an effective
visual scan to reacquire the descending rocket. A higher deployment would give one more time in air before the rocket got lost in the ground/horizon clutter to get a visual on it.

If it really is going to be out of sight for a long time, it behooves one to use an Rf tracker. I base this on the observation at altitude of GPS tracked rockets on descent. Sometimes they track with the prevailing ground winds. Sometimes they
go in mysterious directions that make no sense. I had a DD rocket that would spiral glide on down tail first dragging the main chute bay in a horizontal fashion. It would glide in a circle, stall, descend some more, glide, stall and descend some more until
the main deployment that would blow out perfectly horizontally aft and the whole package would pendulum swing to a vertical final descent under the main. That was always a fun one to watch. Eventually the rocket was
really worn and no longer safe to fly. I built a replacement but it's not the same and flies different.

I blasted a Zenith 2 with an E9-0 booster and C6-7 sustainer with a streamer. Saw the booster flutter in after what seemed a long time and looked to the south and east as that was the direction the rocket went. After what seemed to be a long time, I thought, "Well, God decided to keep that one" and started to get the next rocket ready. I then heard the small beeper, I stuck on the shockcord and the rocket was coming in way towards the north! The ears pointed the eyes and I got a visual. It landed in standing corn not too far in and the beeper allowed me to home in and recover the rocket.

Now if one is putting up a 7lb. rocket on an I, more likely than not the whole flight will be viewable from launch, deployment, to main release and landing. A low main release could save a walk as long as one believes their package has enough time to
get free and inflate. Kurt

 

[H_Rocket]

Used my new Chute Release on a nine pound Warloc on A J350 today with a6' Parasheet. Worked flawlessly on a flight to about 1,300'

One thing I don't like/trust are the tether cords John provides. I am going to beef that up a bit. Not sure how yet, lemme think on it.

 

[ksaves2]

Used my new Chute Release on a nine pound Warloc on A J350 today with a6' Parasheet. Worked flawlessly on a flight to about 1,300'

One thing I don't like/trust are the tether cords John provides. I am going to beef that up a bit. Not sure how yet, lemme think on it.

Go to a local sporting goods store and get some kevlar fishing line at the break test you're comfortable with or purchase some kevlar thread. A spool will last a lifetime. Kurt

 

[kevinkal]

Used my new Chute Release on a nine pound Warloc on A J350 today with a6' Parasheet. Worked flawlessly on a flight to about 1,300'

One thing I don't like/trust are the tether cords John provides. I am going to beef that up a bit. Not sure how yet, lemme think on it.

The two tethers that came with my chute release look like a modern superfiber.. Spectra or Kevlar perhaps. My guess is that the tether is far stronger than the plastic flange that they are cow-hitched to on the chute release.

 

[John Beans]

The two tethers that came with my chute release look like a modern superfiber.. Spectra or Kevlar perhaps. My guess is that the tether is far stronger than the plastic flange that they are cow-hitched to on the chute release.

'

True. 200 lb. test.

But feel free to replace with stronger if it gives more reassurance. For instance, many launch-site vendors will have yellow 300# kevlar line or stronger.

 

[wighty44]

...One thing I don't like/trust are the tether cords John provides.

While I don't know the tensile strength of John's tether cord, I suspect it's substantial.

The one thing I did do for my comfort level is apply a drop of CA glue to the tether's knot.

 

[Ray51]

I noticed from some of the video that the rubber band width was, not very. Would you consider wider exercise resistance bands doable? it would avoid slip more and secure larger packages safely enough. They are very thin, very wide rubber bands, that I think would be mountable on the hardware ends you use while allowing a larger contact area for slip resistance.

It was just a thought as I watched the test video and thought about my Minie Magg parachute bundle. With a useable dual deploy on it, it might be a great rocket to grab my level 2 with a J350.

I am just wondering about the bands used and replacement.

Ray
TRA 04700

 

[ksaves2]

While I don't know the tensile strength of John's tether cord, I suspect it's substantial.

The one thing I did do for my comfort level is apply a drop of CA glue to the tether's knot.

Not good to use CA in knots for anything in rocketry. The CA will make the fibers prone to fracture with lateral loads. If you want to use an adhesive to secure a knot, try an animal based glue with a little "give". Look for something that
says "flexible" in the label. I use an Elmer's wood glue. That's what you want so it allows the fibers to "slide" a bit with lateral loads. CA seizes the material so much it becomes brittle. Just my 2 cents. Kurt

 

[wighty44]

Not good to use CA in knots for anything in rocketry. The CA will make the fibers prone to fracture with lateral loads. ... I use an Elmer's wood glue. That's what you want so it allows the fibers to "slide" a bit with lateral loads. CA seizes the material so much it becomes brittle.

Good to know...

 

[John Beans]

I noticed from some of the video that the rubber band width was, not very. Would you consider wider exercise resistance bands doable? it would avoid slip more and secure larger packages safely enough. They are very thin, very wide rubber bands, that I think would be mountable on the hardware ends you use while allowing a larger contact area for slip resistance.

It was just a thought as I watched the test video and thought about my Minie Magg parachute bundle. With a useable dual deploy on it, it might be a great rocket to grab my level 2 with a J350.

I am just wondering about the bands used and replacement.

Ray
TRA 04700

Substitutions are fine, as long as you can pass the suggested pre-flight shake and release tests.

 

[Cl(VII)]

Include me on the list of true believers. I got to fly an E28 in my D-Region Tomahawk today ONLY because I had a chute release. Otherwise the field would have been too small, but with the chute release I only used about a third of the available downwind (10-12 mph) drift space.

I also witnessed the robustness of the design. Due to a nonejection on a G40 the chute release came in as a balistic payload from about 1500'. It appeared unharmed by the rapid disassembly of the rocket it was a passanger in, and it tested fine. Therefore it earned a test ride in a Mega Mosquito...chute released right on schedule at around 300'. Also head a good story about the 100' failsafe saving the day on a rocket that weathercocked badly and never made the 300' release altitude. It popped at 100' and the rocket was fine.

Now I have seen in person that the case/finish on this product is not only pretty it is increadibly robust. Not too sound too much like a commercial, but this thing is stealing at $129. Every rocket is now easily duel deploy, and many flights that wouldn't stay on the field are now perfectly within margins now without having to plan ahead. I can't believe I'm saying this, but I may retire my cable cutters.

 

[Pat_B]

I had a rocket descend to an altitude that was below my set altitude in the Chute Release due to too long of a delay, and my motor ejection charge hadn't gone off yet. When it did, the Chute Release had already released my parachute inside the airframe so it deployed right away.

 

[Evilash]

I had mine open at 30 ft instead of 300. Very odd event

 

[RalPh8]

I had mine open at 30 ft instead of 300. Very odd event

I had the same thing happen. Set it for 300 and it released as it hit the ground. Rocket was ok though. Soft landing in wet soil

 

[ksaves2]

One caution to heed is if one is tempted to really put a rocket out of sight for a longer period of time, it may drift in a direction one is unaware of. Then, due to a low chosen main deployment altitude, one never sees that rocket and has no idea where to go unless a tracking device is onboard.

It's great to shorten the walk for recovery for a project in a confined launchsite but one should avoid too aggressive
an impulse. Kurt

 

[Oberon]

The "out of sight" issue is the same with a lot if traditional dual deploy rockets I've seen (or rather not seen) fly drogueless. Very hard to track from apogee to main deployment. I think I'm going to start using some fluorescent or Mylar streamers for anything going over 1500 ft or so.

Another thought with "low openings" - if you've got a rocket that weathercocks or is intentionally angled upwind, sometimes a low opening actually leads to a longer walk, because the rocket isn't under chute long enough to drift back.

I will ill say this thing is robust. Mine has survived a CATO and a pretty bad blow-by of the Kevlar blanket (that melted the chute a but) and subsequent hard landings, apparently none the worse for wear.

 

[Buzzard]

As Cl(VII) noted in post 583, a Chute Release survived a prang. That was me. Another DARS member offered me the use of his CR. I prepped my Estes Partizon with an "Estes" G40-7. The motor case failed and the ejection charge popped the payload section and recovery system out. Reprepped with a RMS G76-7. Even after reminding myself to remember the ejection charge, I got distracted and well, the picture says it all.
George saw that the Chute Release still showed ready, he ran the self text, and it worked perfectly on a test flight. He later demonstrated the self test to others.
I will be purchasing a unit when finances allow. And leaving myself big notes...

Chas

 

[Cl(VII)]

As Cl(VII) noted in post 583, a Chute Release survived a prang. That was me. Another DARS member offered me the use of his CR. I prepped my Estes Partizon with an "Estes" G40-7. The motor case failed and the ejection charge popped the payload section and recovery system out. Reprepped with a RMS G76-7. Even after reminding myself to remember the ejection charge, I got distracted and well, the picture says it all.
George saw that the Chute Release still showed ready, he ran the self text, and it worked perfectly on a test flight. He later demonstrated the self test to others.
I will be purchasing a unit when finances allow. And leaving myself big notes...

Chas

Wasn't trying to call you out, Chas, as I know things like that happen to everyone. Your pictures really illustrate what the CR went through and still worked though. Good news on the rocket is the fin can looks good.

 

[Buzzard]

I was actually planning to bring the crash up to demonstrate the robustness of the Chute Release. The payload section took up a lot of the impact, but it still
demonstrated the engineering of this design. Kids - don't try this at home (or the launch field).
Red caps are our friends...

Chas

 

[Banzai88]

'

True. 200 lb. test.

But feel free to replace with stronger if it gives more reassurance. For instance, many launch-site vendors will have yellow 300# kevlar line or stronger.

If my rocket is in the kind of trouble that defeats the 200# tether, it's in the kind of trouble that 300# ain't gonna make any difference! :wink:

 

[ksaves2]

As Cl(VII) noted in post 583, a Chute Release survived a prang. That was me. Another DARS member offered me the use of his CR. I prepped my Estes Partizon with an "Estes" G40-7. The motor case failed and the ejection charge popped the payload section and recovery system out. Reprepped with a RMS G76-7. Even after reminding myself to remember the ejection charge, I got distracted and well, the picture says it all.
George saw that the Chute Release still showed ready, he ran the self text, and it worked perfectly on a test flight. He later demonstrated the self test to others.
I will be purchasing a unit when finances allow. And leaving myself big notes...

Chas

Impressive. Another pitfall is if grease gets into the delay well from underneath and blocks the hole. Am very fastidious about that now.

As an aside, I do like the Dino JLCR protector: https://www.dinochutes.com/Chute-Release-protector_c14.htm.
I have one suggestion for the end user though. Cut a small strip of duct tape and apply it to the serge stitching around the open end of the bag to protect it. I did a full up ground test with a Formula 54 since I am using shear pins and in spite of using a fair amount of dog barf, some of the stitching was singed off. A little CA will help hold the remaining stitches in but the bag certainly did it's job protecting the device. This is more important with a shorter rocket with less distance between the charge and the release device.

 

[John Beans]

Assuming you turned Chute Release on at pad level (and most fields are pretty flat, so that's a safe bet), you can trust that Chute Release will activate at the altitude you select. What is NOT guaranteed is that your chute will immediately inflate. That's a function of your fold, how the chute rides during the tumble or drogue descent, whether a blanket is blocking the slipstream, etc.

I have seen one flight where the parachute was in a pretty loose (not tight rolled) bundle, and the band sank deeply into the folds and got wedged there after release, like a parawad. Ideally, you'll roll a nice tight bundle on a flat surface where you can keep it tight and tidy (shrouds inside is my method) so that the rubber band can't sink deeply in and get wedged. On release, the band springs away from the chute.

If you can inflate in 50 feet, you're doing great. My folds tend toward that number, though they have taken as long as 130 feet below release (I always measure how I'm doing with AltimeterThree, so I'm not just guessing). So if you set for 300 feet and it inflates at 30 feet, it's time to tweak your folding.

If you read about 38mm minimum diameter folding, you'll learn that they can only reef the base of the chute. So during descent the chute inflates quite quickly, since it's already unrolled. You'll of course want to make sure you've got swivels so that the shrouds won't twist, and you'll be tethering your Chute Release to a single shroud line. But that's a technique to try, too, especially if you're tight on space.

 

[o1d_dude]

I had two successful Chute Release (tm) deployments at the Saturday LUNAR launch at Snow Ranch. I'd spent the day and night before experimenting with various methods of bundling the chute AND chute risers. It appears that making the bundle as tight as possible is key as this seems to cause the fire blanket to pretty much spring open when the rubber band releases. Deployment and chute inflation were almost instantaneous.

Chutes used in these trials were a 36" Fruity Chute Classic and a 48" Fruity Chute Classic. The bundles were extremely tight and very hard. Fire blankets were also Fruity Chutes and a bit oversized by conventional standards. Got a bit of a scare on the second flight when the 6.5 lb L2 rocket deployed at 1400' and the motor section began "flying" fins down and ACCELERATING. I'd set the Chute Release for 600' and the 48" Fruity Chute was up to the task. The Goblin 5.5" landed very softly downwind with no damage. Definitely going to use a drogue on that bird next time.

I saw a number of rocketeers setting their Chute Release altitudes ridiculously low (200-300 feet) which scares everyone on the field, caused "Heads UP!" cries and PA system announcements. That's just rude.

Secondly, it's unlikely that at 200-300 feet there is sufficient time to recover in the event of delayed chute inflation. Think about it.

 

[kevinkal]

I had two successful Chute Release (tm) deployments at the Saturday LUNAR launch at Snow Ranch. I'd spent the day and night before experimenting with various methods of bundling the chute AND chute risers. It appears that making the bundle as tight as possible is key as this seems to cause the fire blanket to pretty much spring open when the rubber band releases. Deployment and chute inflation were almost instantaneous.

Chutes used in these trials were a 36" Fruity Chute Classic and a 48" Fruity Chute Classic. The bundles were extremely tight and very hard. Fire blankets were also Fruity Chutes and a bit oversized by conventional standards. Got a bit of a scare on the second flight when the 6.5 lb L2 rocket deployed at 1400' and the motor section began "flying" fins down and ACCELERATING. I'd set the Chute Release for 600' and the 48" Fruity Chute was up to the task. The Goblin 5.5" landed very softly downwind with no damage. Definitely going to use a drogue on that bird next time.

I saw a number of rocketeers setting their Chute Release altitudes ridiculously low (200-300 feet) which scares everyone on the field, caused "Heads UP!" cries and PA system announcements. That's just rude.

Secondly, it's unlikely that at 200-300 feet there is sufficient time to recover in the event of delayed chute inflation. Think about it.

Hi Cranky,
I'm not sure if I've met or indirectly met you. I attended my first ever high power launch Saturday at Snow Ranch LUNAR launch.
Regarding how you packed your chute and fire blanket.. are you saying that you installed the chute release band around both your fire blanket and the chute?
I too have recently studied methods and practiced packing my stock Estes Pro Series II Nylon chutes. I basically followed the method that John shows in his video, where only the chute is held/reefed by the chute release. My first flight with the release had it configured to release my Leviathan's 24" chute at 400 FT AGL. I packed the chute tightly and used the big rubber band even though the instructions suggest the bigger bands are for 36" and larger chutes. (The larger rubber band seemed tight enough to me.. passed my shake test and test releases.) I then wrapped the chute and ejection cord with a 12x12 nomex cloth.. which was loosely around the chute with release and shock cord. On my first/maiden/Level1 Cert Leviathan flight, it worked fine and my Altimeter 3 showed it open between 300 and 400 ft, but the rocket drifted a good ways back still even in the light wind with a straight up shot. My second and third launches with the chute release were with my new Mega Der Red Max. Again I tightly packed the chute per John's video reefing only the chute and loosely packing an 18x18 nomex cloth around the gear. I set the release down to 300' for those flights and it seemed perfect. For those flights 300' seemed like a perfet setting as my MDRM did not free fall too fast, as the body tube with fins seemed to fall in a stable spinning horizontal fashion.
Best,
Kevin

 

[o1d_dude]

Hi Cranky,
I'm not sure if I've met or indirectly met you. I attended my first ever high power launch Saturday at Snow Ranch LUNAR launch.
Regarding how you packed your chute and fire blanket.. are you saying that you installed the chute release band around both your fire blanket and the chute?
I too have recently studied methods and practiced packing my stock Estes Pro Series II Nylon chutes. I basically followed the method that John shows in his video, where only the chute is held/reefed by the chute release. My first flight with the release had it configured to release my Leviathan's 24" chute at 400 FT AGL. I packed the chute tightly and used the big rubber band even though the instructions suggest the bigger bands are for 36" and larger chutes. (The larger rubber band seemed tight enough to me.. passed my shake test and test releases.) I then wrapped the chute and ejection cord with a 12x12 nomex cloth.. which was loosely around the chute with release and shock cord. On my first/maiden/Level1 Cert Leviathan flight, it worked fine and my Altimeter 3 showed it open between 300 and 400 ft, but the rocket drifted a good ways back still even in the light wind with a straight up shot. My second and third launches with the chute release were with my new Mega Der Red Max. Again I tightly packed the chute per John's video reefing only the chute and loosely packing an 18x18 nomex cloth around the gear. I set the release down to 300' for those flights and it seemed perfect. For those flights 300' seemed like a perfet setting as my MDRM did not free fall too fast, as the body tube with fins seemed to fall in a stable spinning horizontal fashion.
Best,
Kevin

Firstly, congrats on your successful Level 1 flight which I may have actually seen.

Secondly, yes, I wrapped the chute and risers inside the fire blanket. The price of Fruity Chutes is painful but I will fly on nothing else. Consequently I take a lot of care to protect them. A quick comparison of prices...my 48" Fruity Chute cost more than the Goblin 5.5" kit...and the reload. The Chute release protects my investment in time spent building the rocket, while the fire blanket protects the the most expensive component.

Let you in on a little secret: I use a second fire blanket wadded up over the top of the motor to protect the tubular nylon shock cord from One Bad Hawk. In effect, there are two blankets and a layer of shockcord protecting the chute.

The smaller Chute Release band will be a tight fight on a 36" chute so i've always used the larger bands. You can use a larger chute with the Chute Release because there's no worry of a cross country chase with an apogee deployment. The larger chutes make for a softer landing so that's another bonus.

 

[KenECoyote]

'
True. 200 lb. test.

But feel free to replace with stronger if it gives more reassurance. For instance, many launch-site vendors will have yellow 300# kevlar line or stronger.

FWIW - This past weekend my friend tried his CR for the first time on a PSII with an F motor and had it set to around 300'. As the CR released on descent, I happened to spot a small rectangular object falling from the bundle and drop straight down. I announced what I saw as it happened and noted that it may be the CR. Sure enough, once the pads were safe and we walked towards where the rocket and object landed, I found his CR on the ground separate from the rocket.

Turns out he used a nylon zip tie band instead of the original tether cord and the zip tie actually broke in the middle of the band. I'd guess it was a combination of the cold (it was maybe 40F) along with the zip tie being stressed from being zipped tight into a very small loop. I mentioned that it's even possible that the pin snapped back and hit zip tie, fracturing it (fairly unlikely, but still possible I would guess).

Just thought I'd pass on the experience. I will continue to use the original tether with mine.

 

[kevinkal]

FWIW - This past weekend my friend tried his CR for the first time on a PSII with an F motor and had it set to around 300'. As the CR released on descent, I happened to spot a small rectangular object falling from the bundle and drop straight down. I announced what I saw as it happened and noted that it may be the CR. Sure enough, once the pads were safe and we walked towards where the rocket and object landed, I found his CR on the ground separate from the rocket.

Turns out he used a nylon zip tie band instead of the original tether cord and the zip tie actually broke in the middle of the band. I'd guess it was a combination of the cold (it was maybe 40F) along with the zip tie being stressed from being zipped tight into a very small loop. I mentioned that it's even possible that the pin snapped back and hit zip tie, fracturing it (fairly unlikely, but still possible I would guess).

Just thought I'd pass on the experience. I will continue to use the original tether with mine.

Thanks for sharing that. I'll not trust a zip tie.

I'm thinking that I will replace the stock 200# spectra chute release tether with small diameter 300# Kevlar, just in case the tether sees hot ejection gases on a bad pack or such.

 

[kevinkal]

Firstly, congrats on your successful Level 1 flight which I may have actually seen.

Secondly, yes, I wrapped the chute and risers inside the fire blanket. The price of Fruity Chutes is painful but I will fly on nothing else. Consequently I take a lot of care to protect them. A quick comparison of prices...my 48" Fruity Chute cost more than the Goblin 5.5" kit...and the reload. The Chute release protects my investment in time spent building the rocket, while the fire blanket protects the the most expensive component.

Let you in on a little secret: I use a second fire blanket wadded up over the top of the motor to protect the tubular nylon shock cord from One Bad Hawk. In effect, there are two blankets and a layer of shockcord protecting the chute.

The smaller Chute Release band will be a tight fight on a 36" chute so i've always used the larger bands. You can use a larger chute with the Chute Release because there's no worry of a cross country chase with an apogee deployment. The larger chutes make for a softer landing so that's another bonus.

I see.. so the Chute release was around the fire blanketed fruity chute... which was above the shock cord and a second fire blanket right on top of the motor mount tube.
Thank you for filling in the blanks for me.

I managed to get a 1" singe a small 18" nylon chute for my "daughter's" Estes PSII Prowler Saturday (Estes F15-6 ejection). Apparently, the Estes wadding and a small scoop of dog barf were not enough or not done right. The singed chute actually helped us in that the rocket came down quickly with the chute bonded together at the singe.. until like magic it peeled itself apart at about 400 ft and came down slow-er right next to a mini van.