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Junior High Power for Needham High School

2 weeks 4 days ago #9457 by Kenn Blade
Lots of good information posted by Curtis and Guy. My only comment would be to think about using a kit for the JRL1 attempt. It may not be as much fun as designing your own but it will show you materials and methods so when you do build your own, you'll do a better job.

I've seen too few college L1 scratch builds that are designed for a simple, reliable flight. They tend to be too small with too little fin area. There seems to be a desire to fly high and fast instead of concentrating on getting the cert. The higher and faster you go with a complex design only increases the opportunities to be disqualified in the cert attempt; whether the tube was too tight for the chute to come out or the chute came out so high the rocket drifted into the trees and was unrecoverable or the lack of stability failed you on the boost ("But the simulation said it was stable.").

If you can get to one of our meetings, we'll be more than happy to fill you with too much information and opinions. At least, you can gauge what you want to do from the discussions you generate.
See you soon.

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2 weeks 3 days ago - 2 weeks 3 days ago #9458 by Frank DeAngelo
Just a few recommendations for a level 1 rocket & certification flight:
At least a 3" body tube, 4" is better.
Use the smallest H motor available from CTI that maintains a 5:1 thrust to weight ratio.
Build the rocket strong.
Use 30 minute epoxy. The longer the cure time the stronger the bond.
Plywood or basswood centering rings and fins at least 1/8" think. I like thicker.
Make inner as well as outer fin fillets.
My level 1 rocket weighed close to 4 pounds. It was a low altitude single deploy flight. I was able to clearly see the rocket throughout the entire flight.
As Kenn stated, keep it simple.
Last Edit: 2 weeks 3 days ago by Frank DeAngelo.

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