Making a streamer?

[Meteor Mike]

If you have a low power rocket that came with a parachute but you want to use a streamer instead, how do you figure what width and length the streamer should be?

 

[mwtoelle]

How heavy is the rocket? How much space is there for the streamer? On something the size of an Estes Wizard (1292) or Viking (1949) to about Alpha (1225) sized, I will use a 2" x 24" length of crepe paper for a streamer. I don't use 1" streamers unless the rocket is smaller than BT-20 or there is not enough room for a wider streamer (Astron Mark). Wider and longer streamers are normally used by people flying streamer duration. YMMV.

 

[goldlizard]

Did you try the Support and Recovery area of TRF. There are links to parachute calculators that will help. If IIRC they use the rocket weight by the feet per second of drop, per diameter/ length.

 

[Meteor Mike]

It's for an Alpha III. Thanks for the info, I'll look into it.

 

[mwtoelle]

When I fly any of my Alpha IIIs, I generally use the 2" x 24" crepe streamer attached to a snap swivel. That size of streamer works well if you are landing on grass or sod. You can't get a much wider streamer in an Alpha III without replacing the body tube with a longer piece of BT-50.

 

[Meteor Mike]

That helps, I'll get some swivels. I picked up some 2" crepe paper today. I'm mainly trying to get a faster descent than with the parachute because I don't want it to float away on the wind and into a forested area where I can't find it like the last one.

 

[Meteor Mike]

Okay, it just occurred to me to cut a hole in the parachute instead (the light bulb suddenly blinks on over my head - duh). I see there's a dotted circle in the center of the chute for this purpose. But it looks like it would leave a pretty big hole. How big of a hole is too big?

 

[cobra1336]

Look into using construction marking ribbon? You know that plastic ribbon they rap around stakes on a building job site. Found in Lowes / home depot. Cheap and you get a lot. Usually only 1 inch wide but it comes wider.

 

[mwtoelle]

Cutting the center out of the parachute will increase the descent rate some, but you will get a faster descent with the streamer. However, I have had some rockets go nearly horizontal with the center cut out. If you flying with many Rocketus eatemupus (rocket-eating trees) in the vicinity, a streamer is probably your best bet.

 

[Meteor Mike]

Rocketus eatemupus (rocket-eating trees)

Ah, so that's what they're called.

Evil things. :dark:

 

[JPVegh]

I put a piece of kite tail (light weight poly) about 1x72 inches in an Alpha thinking that it would be a better choice than a chute on a C6 motor. That son of gun actually thermaled on me and drifted away, I was shocked, I had no idea that a rocket of that size and weight could ride a thermal on such a small streamer.

I also like crepe paper for streamer material, it's light, fire resistant and cheap as heck for a big roll at the dollar store. It can double as wadding in a pinch. I always have a roll in the range box.

 

[LW Bercini]

Okay, it just occurred to me to cut a hole in the parachute instead (the light bulb suddenly blinks on over my head - duh). I see there's a dotted circle in the center of the chute for this purpose. But it looks like it would leave a pretty big hole. How big of a hole is too big?

Don't cut a hole. That can't be undone. Instead, reef the shroud lines in. Make a single wrap of tape around the shroud lines so that the parachute canopy cannot completely open. The higher up you put the tape, the less air the parachute will capture and the faster it will fall.

 

[Meteor Mike]

There's another idea. I'll keep that in mind.

 

[Greg Young]

You get the maximum amount of drag with a 10:1 ratio of length to width.
So basically a 1 inch wide streamer would be 10 inches in length, a 1.5 inch wide 15 inches in length, a 2 inch wide 20 inches, etc.
Lengths beyond that do not appreciably improve descent rates. Also pleated materials used for streamers create more drag than non pleated. Simple crepe paper works great...
The above is based on the studies I have read over the years. Would be interested in hearing if others disagree.

 

[Cookie the Dog's Owner]

3-inch caution tape. $8.00 at Home Depot for a lifetime supply.

 

[Pat_B]

We use a lot of Alpha IIIs for Scouts and I'll generally just give them about 14" of the 2" caution tape. Sometimes that gets a little difficult to pack into the body tube so I'll probably cut the streamer material down to 1" wide in the future and go for a longer length.

 

[mikemech]

I realize that this is an old thread, but Meteor Mike may still be interested.
Cutting a hole in a 'chute is to reduce swinging of the rocket during descent, not primarily to increase drop speed. As L.W. Bercini said, once the hole is cut, you cannot uncut it. This is still a useful technique. I have 12" chutes with 2", 4", 6", and 8" holes. If you like, as I do, smaller rockets, you will have 12" 'chutes coming out of your ears.
Streamer material is so cheap that you can have many sizes and materials. I have plastic, crepe paper and mylar of different widths and lengths. Some have slits cut lengthwise or crosswise to decrease drop speed with very little drift. For an Alpha I would star with a 3" x 30" crepe paper streamer with 1"-1.5" slashes across the streamer about every six inches. Accordion fold the first 24" then roll the rest around the folds. Wrap 1-2 sheets of wadding around the streamer pack, you won't e able to get a full wadding pack in the Alpha with a 3" streamer.
Try different stuff and have fun. Now go launch something!

Mike

 

[JStarStar]

Parachutes with spill holes are especially bad for getting snagged in trees.

A straight streamer will sometimes slide straight through.

 

[hcmbanjo]

I put a piece of kite tail (light weight poly) about 1x72 inches in an Alpha thinking that it would be a better choice than a chute on a C6 motor. That son of gun actually thermaled on me and drifted away, I was shocked, I had no idea that a rocket of that size and weight could ride a thermal on such a small streamer.
I also like crepe paper for streamer material, it's light, fire resistant and cheap as heck for a big roll at the dollar store. It can double as wadding in a pinch. I always have a roll in the range box.

Another streamer material can be cut from plastic sheeting made to cover a picnic or party table.
A large sheet is only a dollar from the dollar store. You can buy it in any color you want.
When cutting, don't open the big sheet all the way. Open a few folds and you can cut through many layers at once.
It's also a pretty good parachute material.

As mentioned, for streamers you can pick up the crepe paper rolls there too, $1.00 for two rolls.
Most of the time I use that for wadding. Just cut it up in squares.
It's stiffer than the Estes toilet paper but easier to pack than the Quest wadding.
And a WHOLE lot cheaper!

 

[dward]

You get the maximum amount of drag with a 10:1 ratio of length to width.
So basically a 1 inch wide streamer would be 10 inches in length, a 1.5 inch wide 15 inches in length, a 2 inch wide 20 inches, etc.
Lengths beyond that do not appreciably improve descent rates. Also pleated materials used for streamers create more drag than non pleated. Simple crepe paper works great...
The above is based on the studies I have read over the years. Would be interested in hearing if others disagree.

+1 on that. Comes from an MIT student back in the 60's or early 70's.

Mylar makes a good streamer when folded accordion style.

 

[apburner]

3-inch caution tape. $8.00 at Home Depot for a lifetime supply.

Yep that stuff is great. I used a bunch this weekend on a few scratch built rockets I had not fixed a recovery device to. They all worked great. And I still have almost a whole roll left. LOL