I have had bad luck with streamers.

For some reason I have had bad luck with streamer recovery. Of the recent rockets that have used streamers only the smallest (like my Semroc Lil' Ivan) have come down without damage. My Goblin had a small (and fixable) crack along a fillet, and the My Boid and Quest Totally Tubular both plummeted out of the sky and landed very hard. (Find my "Rocket Surgery" thread in the Low Power section.)

So, do I need longer streamers than what have been in the kits? I switched the Tubular to a 12" chute with a spill hole and it came down close and gently. I think I'll do the same with the Boid.

Any suggestions?

Or use a 10'' chute(might have to make your own) and add a 2'' hole, I did that on my 2stage rocket.

The Estes Goblin was supposed to recover on a streamer, but that was always an iffy proposition due to its mass and the shape and orientation of its fins. After repairing fins a few times, many people ended up doing exactly what you did, switching to a parachute with a spill hole. I have always used an unmodified 12" parachute in my Goblin clone and it has always come down inside the recovery area and never more than a short walk from the pad.

You can increase the size of the streamers in your other rockets to increase the drag and slow down the descent a bit. Increasing the length helps more than increasing the width.

You can also give the streamer an accordion fold and when it unfurls, the creases in the material will produce more drag.

If these are sport rockets, then use whatever type of recovery works best. Unless the rocket is recovering from very high altitudes and you need to keep the drift to an absolute minimum, then a parachute modified with a spill hole is a good alternative to a streamer. The rocket can potentially drift farther on it than it would do on a streamer, though.

I know also that there is a finite ratio between streamer length and width...the idea is that a streamer that is TOO long will not 'flap' and so causes the rocket to come down faster than expected.

Also, temperature may have something to do with it...yesterday I flew my Mini Max and Der Big Mini Max and both of them broke a fin, something that hadn't happened in all the other times I flew them. I suspect my streamers, though I had unrolled and rerolled them before flight, were still too stiff from cold soaking this winter.

FC

I think I'll have streamers on the very light and minimum diameter rockets and stick with chutes of various kinds for others.

The ratio is typically accepted as 10:1 based on some wind tunnel tests performed by the MIT rocket society.

Your typical party streamer materail is about 2" wide and cut to 20" make great, inexpensive streamers which are also flame retardant

jim

FastCargo said:

I know also that there is a finite ratio between streamer length and width...the idea is that a streamer that is TOO long will not 'flap' and so causes the rocket to come down faster than expected.

Also, temperature may have something to do with it...yesterday I flew my Mini Max and Der Big Mini Max and both of them broke a fin, something that hadn't happened in all the other times I flew them. I suspect my streamers, though I had unrolled and rerolled them before flight, were still too stiff from cold soaking this winter.

FC

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Another trick I tried this weekend on my Big Bertha is used one long streamer (8') but tie both ends to the shock cord about 8" apart. It billowed out just like a parachute and it slowed the rocket down alot, but it didn't have the drift of a parachute. It also is alot easier to spot a 4 foot circle floating down than a long string or a 10" parachute.

jflis said:

The ratio is typically accepted as 10:1 based on some wind tunnel tests performed by the MIT rocket society.

Your typical party streamer materail is about 2" wide and cut to 20" make great, inexpensive streamers which are also flame retardant

jim

Click to expand...

I will second the use of 2" x 24" crepe streamers on light rockets. I only use 1" wide streamers on rockets that do not have enough room for a 2" x 24".

My experience has shown that the 10 to 1 ratio rule is false. Adding more length makes for a slower decent. This has proven to be the case in my own experiments with streamer length. Streamer material and how it's folded seem to be the biggest factor in descent rate. However in contest rocketry slower descent does not always equal more duration, you need to find the right balance between altitude and descent to make the most of duration times. More streamer means more weight means less altitude. In sport rocketry where duration is not an issue a longer streamer may benefit. A small light weight chute will usually have a lower descent rate than even even a long streamer, I think you've already discovered this for yourself. A long streamer adds the benefit of higher visibility both in the air and on the ground. You need to make the call based on your field and launch conditions.

Crepe is definitely a preference of mine in sport rockets. As was already mentioned crepe is cheap and fire retardent it is also has more texture than other materials commonly used for streamer. For contest rockets I prefer something that takes and holds a crease like mylar or tracing paper this of course means you need better protection from the ejection gasses.

If the small chutes are working for you then that may be what is best. Streamers are not immune to drifting off. I've lost quite a few rockets that have drifted a long ways on a streamer.

Spacepirate R said:

For some reason I have had bad luck with streamer recovery. Of the recent rockets that have used streamers only the smallest (like my Semroc Lil' Ivan) have come down without damage. My Goblin had a small (and fixable) crack along a fillet, and the My Boid and Quest Totally Tubular both plummeted out of the sky and landed very hard. (Find my "Rocket Surgery" thread in the Low Power section.)

So, do I need longer streamers than what have been in the kits? I switched the Tubular to a 12" chute with a spill hole and it came down close and gently. I think I'll do the same with the Boid.

Any suggestions?

Click to expand...

How much did your rocket weight?

You need a minimum streamer area of 8.5 cm2 per g of rocket mass according to the Rocket Reviews Streamer Calculator

The MIT Rocket Club conducted a streamer study in the early 70s that indicated the most efficient streamers have a 10:1 length to width ratio. This is widely misinterpreted that streamers longer than 10:1 won't work or have a lower descent rate than a 10:1 streamer.

Bob

bobkrech said:

The MIT Rocket Club conducted a streamer study in the early 70s that indicated the most efficient streamers have a 10:1 length to width ratio. This is widely misinterpreted that streamers longer than 10:1 won't work or have a lower descent rate than a 10:1 streamer.

Click to expand...

I would interpret this to mean that a single 20:1 streamer would not work as well as two 10:1 streamers, or maybe that a 1" x 40" streamer would not work as well as a 2" x 20" streamer, even though they are the same surface area.

I never had much interest in streamers although I have used them a few times. But recently my local club has been restricted to a pretty small field, and just having one day a month to launch sometimes you have to accept windier conditions than you would like. SMALLFIELD + WIND = STREAMER so I'm building a few new rockets specifically to use streamers. At some point I'll have to determine how to get big enough streamers to work because these won't be small rockets.

bjphoenix said:

I would interpret this to mean that a single 20:1 streamer would not work as well as two 10:1 streamers, or maybe that a 1" x 40" streamer would not work as well as a 2" x 20" streamer, even though they are the same surface area.

I never had much interest in streamers although I have used them a few times. But recently my local club has been restricted to a pretty small field, and just having one day a month to launch sometimes you have to accept windier conditions than you would like. SMALLFIELD + WIND = STREAMER so I'm building a few new rockets specifically to use streamers. At some point I'll have to determine how to get big enough streamers to work because these won't be small rockets.

Click to expand...

Yes, a 2"x20" will be more optimal and hence have more drag than a 1"x40", according to the data. That is, you get more drag for the same mass (payload) of streamer.

The two 10:1's should work better than a single 20:1, but if you factor in them being in contact with each other, that may affect things.

As for small fields and wind, a streamer won't necessarily bring a rocket down any faster, any nearer the pads, than a chute. It all depends on how much streamer you use. That is, if you want to bring something down fast, a smaller chute works well for that, too.

The real advantages to a streamer, IMO, are less jerk on the recovery harness at deployment and easier to track in the sky. If you're flying in wind, for example, you may well get some weathercocking and hence chute ejection while the rocket's travelling at a good speed horizontally - a good scenario for a zipper/shred/separation. The streamer won't jerk on the harness like a blossoming chute will, so it lessens the chances of a problem.

If you use mylar streamers, they really help find it in the sky when you're pushing the envelope. If you fly that D-C-C stack in your Comanche, having a long mylar streamer glinting in the sun is a major asset That is, I've found the streamers to be easier to spot in the sky that the chutes are.

One other advantage to streamers is that they pack a little more easily than chutes do, IMO.

Doug

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Well, I am still having mixed results. I think that the ground is too hard here and the grass is quite dry. I launched my Estes Viking and it popped a fin on landing even though it seemed that the streamer was bringing it down alright.:confused2:

My repaired Goblin goes great on a C11-5 and that long streamer is very visual, but a fillet cracked again. At this rate it will completely encased in glue.

The only rockets that have consistently survived streamer recovery are my Quest Cobalt and my Semroc Lil' Ivan.

I will try the Goblin on a 10" or 12" chute with a spill hole and see what that does. A B6-4 should be good for a test before I bump it up to the big C. I might use some smaller streamers along with the chute for visibility.

Spacepirate R said:

For some reason I have had bad luck with streamer recovery. Of the recent rockets that have used streamers only the smallest (like my Semroc Lil' Ivan) have come down without damage. My Goblin had a small (and fixable) crack along a fillet, and the My Boid and Quest Totally Tubular both plummeted out of the sky and landed very hard. (Find my "Rocket Surgery" thread in the Low Power section.)

So, do I need longer streamers than what have been in the kits? I switched the Tubular to a 12" chute with a spill hole and it came down close and gently. I think I'll do the same with the Boid.

Any suggestions?

Click to expand...

You pretty much answered your own question. Use a parachute.

RocketManDan said:

You pretty much answered your own question. Use a parachute.

Click to expand...

Yep. I got an Estes Wizard in the build cue and I'll try chute and spill hole on it. If that works then when I fix the Viking (again) I'll do the with it too.

Good thing I have a lot of trash bags around.

Spacepirate R said:

For some reason I have had bad luck with streamer recovery. Of the recent rockets that have used streamers only the smallest (like my Semroc Lil' Ivan) have come down without damage. My Goblin had a small (and fixable) crack along a fillet, and the My Boid and Quest Totally Tubular both plummeted out of the sky and landed very hard. (Find my "Rocket Surgery" thread in the Low Power section.)

So, do I need longer streamers than what have been in the kits? I switched the Tubular to a 12" chute with a spill hole and it came down close and gently. I think I'll do the same with the Boid.

Any suggestions?

Click to expand...

The Goblin has always been flown with a 2" x 120" crepe paper streamer. I'm still flying one build originally in the mid 80's recently rebuilt using as many of the original parts as possible to replace the charred motor mount and and burned fin tailing edges for the mighty D12's
Of all the flights this bird has had I can only thing of one time I popped a fin on landing. The trick with Crepe Streamer is to replace them when the rough surface becomes smooth (10-15 flights). Crepe paper is flame resistent treated so they are easily traded with any color 2" wide crepe party store ribbon you'd like.

Crepe and Tracing vellum streamer are the only streamers that have been shown to hold to the 1-to-10 ratio. smooth surface materials like mylars, caution tape and surveyers tapes can be much longer and be vary effective.

Accordian folding mylars (at least 2/3rd of the overall streamer length) will drasticly slow the return on most light weight models as long as the material has the strength to HOLD the creases during flight. 1/2, 1 & 2mil mylar do hold creasing well. Plastic caution tape and 1/2, 3/4 and 1" surveyers tapes do not. it's also possible to buy sheets of wrapping mylar Most are 1/2 or 1mil thick in 2'x3' sheets. these can be taped together into as long a streamer as you need with mylar wrapping tape. I like using 4" wide strips about 12feet long of orange mylar. in the sun it looks like flame falling from the sky trailing behind the model. I've used streamers on models Up to 12oz. with no damage at all. it's a matter of matching the models empty weight with motor casing to the streamer width and length decent rate you want. There are EASY calculators over on EMRR and Yorf for your use.

What would happen if you attached a chute to the end of a streamer? Would that be good for reducing opening shock in the case of an early ejection?

Micromeister said:

The trick with Crepe Streamer is to replace them when the rough surface becomes smooth (10-15 flights).

Click to expand...

As my Goblin has only flown 5 times with only once ripping a fin I am positive that it is the local ground conditions. It does take a long time to come down with the streamer, it's just a little too fast when it hits and I end up having to apply more glue along the fin roots.

Shoot, I've had some of my rockets with chutes ding up their fins with what seemed like a gentle landing. If the grass was lush and the dirt was not so packed and dry then I think my Goblin would be looking great.

CarVac said:

What would happen if you attached a chute to the end of a streamer? Would that be good for reducing opening shock in the case of an early ejection?

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Interesting idea, but the streamer material has to be pretty robust stuff. It would (theoretically) lessen the opening shock, and it may reduce the snap-back of the nose cone (again theoretically).

A long elastic shock cord with a streamer layed on top of it might be worthy of trying. If nothing else, just to see if the shocks are reduced.

MarkII said:

Unless the rocket is recovering from very high altitudes and you need to keep the drift to an absolute minimum, then a parachute modified with a spill hole is a good alternative to a streamer. The rocket can potentially drift farther on it than it would do on a streamer, though.

Click to expand...

I've heard 'chutes with large spill holes refered to as "circular streamers."

If the parachute brings the rocket down at the same speed as the streamer, however, the drift will be the same. Streamers have several advantages though. In addition to being easier to pack and easier to see at high altitudes, they are less likely to catch in trees or get snagged by power lines. And, in areas with tall grass or corn fields, they can make the rocket easier to find on the ground.

-- Roger

CarVac said:

What would happen if you attached a chute to the end of a streamer? Would that be good for reducing opening shock in the case of an early ejection?

Click to expand...

I've seen that done for a few high-power rockets. I'm not sure what the advantages might be. It looked cool and may have been more visible than the 'chute alone.

I've also seen people use really long streamers along with parachutes - usually when flying near corn fields. When the rocket lands in the corn, the streamer is visible on top of the stalks.

-- Roger

Another advantage of long streamers is helping to locate the rocket in deeper foliage. I had a stock Fat Boy that I recovered on a 4 or 5 foot long mylar streamer. The rocket would go through the underbrush, but the streamer would lay on top, pointing the way to the rocket.