Best streamer width to length ratio?

[RazorConcepts]

Most online sources say that a width to length ratio of 1:10 was the best, however I recently purchased an Apogee Technical Publication (from the 90s) that stated while 1:10 was popular, 1:5 was the best.

So what is the best ratio? Thanks!

 

[tibadoe]

.........So what is the best ratio? Thanks!

Looked it up in G. Harry Stine "Handbook of Model Rocketry". It states the best length to width ratio is 10:1.

 

[madsen]

Looked it up in G. Harry Stine "Handbook of Model Rocketry". It states the best length to width ratio is 10:1.

Never doubt Harry. Even from the grave--he is right.

 

[RazorConcepts]

Thanks! I cut down by 4" x 56" mylar streamers to 40".

But how do I attach these streamers to the rocket? I have kevlar that can attach to the rocket easily, but the kevlar > mylar streamer attachment method is escaping me.

 

[MarkII]

Materials:
- a piece of cereal box-weight cardboard, 3" long x the width of your streamer
- spray adhesive or something else that bonds to Mylar (CA?) and also some white glue or a heavy-duty desk/office stapler
- a small amount of duct tape
- a length of 1/4" wide elastic, that is as long as the width of your streamer + 4"

1. Fold the piece of cardboard it in half so that it is now 1.5" long x the width of the streamer. Then fold it again (letter-fold) into three sections, each 1/2" long x the width of the streamer.
2. Now unfold it. On the 1.5" length of the cardboard that is toward the outside of the folds, apply spray adhesive or whatever you can use to bond Mylar, and then bond one end of the Mylar streamer to it so that it covers that 1.5" length.
3. Then fold the cardboard in half as before and glue the two halves together.
4. Now cut a thin strip of duct tape or electrical tape and use it to cover the inside of the remaining fold that is further away from the end (closer to the streamer end).
5. Take the 1/4" elastic, lay it on the taped fold so that an equal amount (2") extends past the edge of the streamer on each side, and tape it down lightly using more duct tape.
6. Now fold the cardboard up the rest of the way, bonding it with glue to keep it from unfolding. (White glue will probably work here. You could also just staple it together, too.) The fold that contains the elastic should now be on the very end of the streamer.
7. Tie a couple of small loops (you can use slip knots) that are a streamer's width apart into your Kevlar shock cord a few inches below the nose cone.
8. Use the two ends of the elastic to tie the streamer to the two loops in the shock cord. Tie it right up tight against the Kevlar.

MarkII

 

[gpoehlein]

Thanks! I cut down by 4" x 56" mylar streamers to 40".

But how do I attach these streamers to the rocket? I have kevlar that can attach to the rocket easily, but the kevlar > mylar streamer attachment method is escaping me.

What I do is apply a strip of Scotch tape across the base edge of the streamer on both sides, and trim off the excess (don't want any exposed adhesive). I've got a set of small hole punches that I found in the scrapbooking section of one of our local craft shops and I use that to punch a 1/8" hole in the center of the tape. I then tie the shroud line (I usually use cotton carpet thread) through the hole with a bowline or figure 8 knot. I haven't had a shroud line/streamer failure yet in competition.

BTW, I usually use 4x40 or 5x50 streamers made from mylar space blankets. I roll the new streamer around a dowel or brass rod, pull it off and iron it flat with a covering iron. I unroll the streamer and backfold between each fold so the streamer has a nice zig-zag fold. Finally, I color one side of the streamer with a red magic marker to make it nice and visible. Beautiful streamers for very little $$.

 

[WillMarchant]

The latest Sport Rocketry talks about a NARAM R&D report re-investigating the streamer aspect ratio question...

 

[MarkII]

BTW, I usually use 4x40 or 5x50 streamers made from mylar space blankets. ... Beautiful streamers for very little $$.

But is the space blanket material actually thick enough, Greg? I bought one at Walmart last year specifically for that purpose, but I wasn't really happy with the "dry cleaner bag" thickness of it, and, conversely, also the crinkly-ness of it. I was hoping that the material was just a bit more substantial. (That's an odd thing to say about Mylar, I know.) Also a bit more docile and well-behaved. I like the idea, though. I bought a pretty good-sized blanket for $1.

They don't yield that much material, but a good source for Mylar streamers for Micromaxx rockets are the empty wrappers from cereal bars. The wrappers are made from Mylar, too. (Or something that closely resembles it.)

MarkII

 

[gpoehlein]

They work for me fine in the several contests I've used them in. As for durability, I've got one 4x40 streamer that has survived five or six flights now. I've also used it for chutes but it is a little too stiff for contest use and I've got some thin (.55 mil) black garbage bags that makes better thermalling chutes. Like I said, you really need to iron in the pleats, but once you do it holds them well.

 

[JRThro]

...I've got some thin (.55 mil) black garbage bags that makes better thermalling chutes.

OT, but do black parachutes do thermals better?

 

[gpoehlein]

OT, but do black parachutes do thermals better?

I think so, but then I've only been competing for three years now. Because they are nice and flexible, I've watched them "jellyfish" in a thermal. And I've watched more than one rocket on a 30 to 36" black trash bag chute thermal away (including my dual egg rocket last year). More to the point, the black plastic remains visible for longer than a white chute under most sky conditions. And, given their size, I can get a nice big 36" hex or octagon chute out of one trash bag. (over the top shroud lines are a must for these babies!)

 

[MarkII]

They work for me fine in the several contests I've used them in. As for durability, I've got one 4x40 streamer that has survived five or six flights now. I've also used it for chutes but it is a little too stiff for contest use and I've got some thin (.55 mil) black garbage bags that makes better thermalling chutes. Like I said, you really need to iron in the pleats, but once you do it holds them well.

You're right; ironing the material would probably help. I wasn't intending to put pleats in mine (at least not at first), but ironing the Mylar flat might help it lay down and be more cooperative when I want to fold it. (Does that make sense? It sounds contradictory, I know.)

One type of Mylar (for sport rockets) that I really like is silver Dura-Lar from ASP. I would compare it in thickness to movie film, but it is very flexible. It is very tame and easy to handle when you are doing the repeated end-double-fold method of folding a sport streamer. It is also much tougher than the standard Mylar that is usually used for parachutes and streamers. Even though it is appreciably thicker than standard Mylar, it is still quite thin and it can be easily folded and rolled up to fit into any size of body tube. Andy included a sample of it in an order I placed a couple of years ago, and I was immediately impressed. It isn't the type of ultrathin, ultralight Mylar that you would use for competition (he sells that kind, too) but it is great for sport rockets.

MarkII