Bottle Rocket B

[thewinner]

I know, I just said angling fins won't help you fly any higher.

[drifter601]

What exactly is center of pressure and how do you find it???

[space scientist]

What exactly is center of pressure and how do you find it???

The explanation for how you find the center of pressure is on page 13, and I don't know the exact definition of the center of pressure although the term is misleading in that it is about the stability of the rocket.

[Jocool]

It is the point where all wind forces will pass through when the rocket is in a stable flight position.

[Rocketeer]

Do the rockets need a guide tube? I can not tell from the rules sheet I got. I can still add one to rocket number five and six (the others were destroyed spectacularly)

[MVStangs]

MVStangs, what materials are you using to make your backslider and what's your shape?

We're using a long paper nose cone on top of the bottle. We also put clay on the top of the bottle to pull back the COG. It works pretty well, but we've heard of way better times. For fins, we have this plastic material that is light but not that heavy. We put them on there in such a way that the rocket spirals up and goes up farther. It helps, but does anyone else have better ideas?

[fleet130]

Do the rockets need a guide tube?

Check the rules. If it is required, they will say so. If they don't say it's required, then it's not needed.

[Primate]

MVStangs, what materials are you using to make your backslider and what's your shape?

We're using a long paper nose cone on top of the bottle. We also put clay on the top of the bottle to pull back the COG. It works pretty well, but we've heard of way better times. For fins, we have this plastic material that is light but not that heavy. We put them on there in such a way that the rocket spirals up and goes up farther. It helps, but does anyone else have better ideas?

Make your nose cone lighter and/or longer. You want to get your design to the point where you don't need to add weight to the tail, since that'll decrease your altitude significantly. Our first nose cone was just the entire sheet of paper rolled up; cutting the posterboard to fit ahead of time halved the weight of the cone. We didn't need additional weight with the second nose cone, and the rocket flew almost twice as long.

[space scientist]

MVStangs, what materials are you using to make your backslider and what's your shape?

We're using a long paper nose cone on top of the bottle. We also put clay on the top of the bottle to pull back the COG. It works pretty well, but we've heard of way better times. For fins, we have this plastic material that is light but not that heavy. We put them on there in such a way that the rocket spirals up and goes up farther. It helps, but does anyone else have better ideas?

For a backslider design, the weight of the rocket doesn't matter as much as where the center of balance is unless the rocket is really heavy. Today, a bottle rocket that I built with the center of balance halfway in between the center of pressure and center of lateral area got a time of 6.63 seconds while going in an arc that was caused by a somewhat strong wind.

[Orchdork]

what types of times r u getting? I go to IL state compitiotion tomorrow so there's not much I can change to my rocket so I'm praying I get a good time and a medal. Good Luck to everyone!!