NARAM-50

Event Tips Pages (draft)

For NARAM-50, the Streamer Duration event is for B engine class.

Streamer Duration combines the challenge of building a light rocket that can fly high (to a good altitude to descend from), with a streamer that can slow the descent as much as possible for a good duration time.

In Streamer Duration, the model has to remain in one piece throughout the flight and cannot be staged.

Multi-Round - This form of duration scoring involves "Max" times and three flights. For B Streamer, the maximum time is 180 seconds. As an example, if the model stays in the air for 216 seconds, it's official time is 180 seconds. However, 180 seconds is a hard to reach max time for models powered by 18mm black powder B engines (the only B's currently contest certified), even 120 seconds is difficult without major help from thermal activity.

Models in multi-round scored events DO NOT have to be returned, but only two models are allowed. This means that you need to return one model to make your third flight . And if you make it to a flyoff, you'll need a returned model for the fourth flight round.

For the full rules for this event, please see the Streamer Duration Rules on the NAR web page, as well as the multi-round rules (15.12).

Scoring - For Multi-Round Streamer Duration, the scoring is the sum of all of the qualified flights. If there is a tie for first place at the end of round three (normally three maxes), there will be a fly-off round between those contestants who are tied, with the max time increased by at least 60 seconds.

Design considerations - There are trade-offs between the model's performance and the streamer's size. Low-mass and low-drag models may not be strong enough to survive boost. Increasing the size of the streamer means the streamer will need more room inside your rocket. A bigger streamer is also heavier, which could weigh down the model too much.

A list of plans and kits is included further down on this page.

Streamers - Streamer choice and preparation is important. Simple crepe paper just doesn't do it. Some people use a certain grade of tracing paper, while others prefer to use 1 mil mylar. The tracing paper can perform well, but also can rip more easily than other materials. So, 1 mil mylar is recommended. For B power, 6" by 60" streamers are a good size.

The trick to good performance out of the streamers is to put folds into them. The folds improve the "whip" action of the streamers. Some people use simple accordion type folds, or pleated folds, with the folds spaced about 1/2" apart or so. Others roll the streamer up on a 3/16" dowel, slide the rolled streamer off, then squash the rolled streamer flat to give it folds that run the same way, as opposed to zigzag accordion pleats. In any case, just pressing the folds is not good enough for mylar streamers, the folds will not set as well as desired for good performance. Heat from an iron is needed. Either use an old iron or apply some scrap cloth over the iron to protect the iron. Lay the iron over the folded or rolled/flattened streamer and let it heat as deeply as possible for many minutes. After you are done, place the streamer under some heavy object to keep the folds tight while it cools off. Shock Cords - Kevlar Shock cords of 100 pound grade are recommended. Use a 3 to 4 feet length from the main body to the streamer. Attach the cord securely to the streamer so that it cannot come off. Many people like to use a 1" wide piece of tape folded across the bottom of the streamer, trapping the shock cord. But the cord could still slip free, so put a few knots into the portion of the cord that will be under the tape. The adhesive tape should be a type that will not rip easily, not scotch tape or masking tape. For extra strength, you can add a piece of 1/2" wide strapping tape as shown.

Tips and info from other sources:

• A Must-Read Lecture article (.pdf) on building and flying Streamer/Parachute Duration, written by Pavel Pinkas of the WOOSH section. Lots of useful all-around information for flying Streamer Duration and Parachute Duration.
• Some Notes on Tracing Paper Streamers, by Andy Jackson from the ASP website. The first two paragraphs are useful for any streamer type, regardless of material.

Engine recommendations for B Streamer Duration:	B4-4 or B6-4 (less than ideal streamer models - somewhat draggy or heavy)
or	B6-6 (low drag light streamer models)

Model Plans & Kits

Designer

Notes

DarkStar PD/SD plan (18mm) (WOOSH website)

plan by Mark Talkington

PDF file of an 18mm model suitable for Streamer and Parachute Duration

ASTRE PD/SD model plan (NAR website)

plan by Jeff Vincent

PDF file of 13mm and 18mm PD & SD models

ASP "Streamer Duration" Kit  #KSDT - 18 (18mm)

ASP (Aerospace Specialty Products), Andy Jackson

Good competitive kit for 18mm engines.

QCR - "Straight Up I " Parachute/Streamer Duration kit for 18mm engines

QCR - Qualified Competition Rockets, Ken Brown

Good competitive kit for 18mm engines.
(specify streamer recovery when ordering)

Apogee "Blue Streak" sport model kit

Apogee Components

Not designed for contest use, but can be a decent model when modified to use a good contest streamer.

ESTES- "Wizard" sport model kit.

Estes Industries

Not designed for contest use, but can be a decent model when modified to use a good contest streamer.

Pratt Hobbies "Super Six" kit

Doug Pratt

A sport model kit that looks and flies like a contest model.