Bottle Rocket B

[Primate]

or i could build a triangle like for using straws and srtetching a plastic bag over it so the fins are hollow. and it works freaking amazing.

I'm not sure I follow. What exactly are you describing?

[Cheesy Pie]

I heard you should place the fins at an angle (and use 3 fins).

[robotman]

I heard you should place the fins at an angle (and use 3 fins).

What kind of angle?
If you do it right you can get it to spin

[Cheesy Pie]

I heard you should place the fins at an angle (and use 3 fins).

What kind of angle?
If you do it right you can get it to spin

20-30 degrees, I think.

[coterotie]

Got to 20+ seconds today w/ a slightly over pressured underwatered rocket. Competition is Saturday. Have a heavier waterproof rocket in case the weather is bad. I am worried that if there is a strong wind and rain, the lightweight rockets won't perform well.

Stopping testing and just doing a final cleanup and making a clone as backup. Using 4 fins and am a little curious about how 3 fins might work.

Curious about weights. Lightest rocket weighs around 4 oz. Anyone else care to share weights?

[Frogger4907]

The fins are in place for stability, by holding you rocket in your hand and acting like it is traveling off course, you can assume that by having either 3 or 4 fins would stabilize it, 3 is obviously lighter. So 3 will probably be more successful however whether you have 3 or 4 will provide very slight differences in time.

[Cheesy Pie]

At the tryouts (around 20 psi), I used 3 fins and a round nosecone. 3.70 (pretty good for 20 psi( or at least compared to other rockets))

[space scientist]

This is just a question, but shouldn't the center of balance of the bottle rocket be near half the length of the bottle rocket and in front of the pressure vessel?

[kittykat]

Wooh got a 30.56 flight time!!

[space scientist]

Wooh got a 30.56 flight time!!

That is great. I remember from earlier in this thread that people were expecting maximum times of 30 seconds.