Bottle Rocket B

Locked
User avatar
Primate
Member
Member
Posts: 409
Joined: January 15th, 2009, 4:34 pm
Division: C
State: NY
Has thanked: 0
Been thanked: 0

Re: Bottle Rocket B

Post by Primate » April 15th, 2011, 4:27 pm

space scientist wrote:
MVStangs wrote:
Primate wrote: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.
To get it to backslide, probably not. However, I've found that, for backsliders, the weight of the nose cone is usually enough to put the rocket over its optimal weight, so you don't want to add any additional weight if possible. And obviously, a lighter rocket will fall much more slowly.
events 2012 gravity vehicle, robot arm, thermodynamics, tps

Tramsarran
Member
Member
Posts: 74
Joined: February 13th, 2011, 6:11 pm
Division: C
State: NY
Location: Life
Has thanked: 0
Been thanked: 0

Re: Bottle Rocket B

Post by Tramsarran » April 15th, 2011, 8:01 pm

Orchdork wrote: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!! :)
Good luck! I got pushed into Tier 2 because the person who built the rocket used Super Glue and it had visible interfered with the strength of the plastic. Got 39 place and the rocket stayed for a little under 3 seconds. The best times that I had witnessed was about 20 seconds from a perfect backsliding rocket that seemed to float as it came down; it was amazing. A time of about 10-15 seconds is really good from what I saw as many rockets nosedived and dug 2-3inch holes into the ground. Whenever you're not at a event you might wanna watch the Bottle Rockets launch it was the most exciting event next to Sumobots in my opinion.
Goodbye Science Olympiad, until next year.

User avatar
fishman100
Exalted Member
Exalted Member
Posts: 478
Joined: January 28th, 2011, 1:26 pm
Division: Grad
State: VA
Has thanked: 0
Been thanked: 0

Re: Bottle Rocket B

Post by fishman100 » April 16th, 2011, 4:00 pm

Are balsa wood fins better than plastic fins?

Balsa seems to break easily, but depending on the thickness, it can help your rocket.

What did you use?
Langley HS Science Olympiad '15

Tramsarran
Member
Member
Posts: 74
Joined: February 13th, 2011, 6:11 pm
Division: C
State: NY
Location: Life
Has thanked: 0
Been thanked: 0

Re: Bottle Rocket B

Post by Tramsarran » April 16th, 2011, 4:11 pm

I built one out of some posterboard foam that was quite sturdy and would not crease but I didn't bring my rocket to the competition as another teammate built two other rockets. He also forgot the labels so I asked another group to borrow their labels after they launched their rocket and fortunately they gave it to me.
Yeah, balsa wood sounds like a good idea.

It really depends on what type of plastic you use and what type of rocket you are building. If you use really flimsy plastic the fins might be useless. If you use sturdy plastic that will hold its shape but not lower the COG too much it should work fine.
Goodbye Science Olympiad, until next year.

thewinner
Member
Member
Posts: 110
Joined: March 18th, 2011, 12:18 pm
Division: B
State: NJ
Location: TGMS FTW
Has thanked: 0
Been thanked: 0

Re: Bottle Rocket B

Post by thewinner » April 17th, 2011, 5:13 am

I use some sort of corrugated plastic (you know, that material you use in signs). It works really well and is very strong.
I win.

User avatar
Littleboy
Member
Member
Posts: 373
Joined: March 14th, 2010, 4:53 pm
Division: C
State: MI
Location: Between the Earth's Core and Mars.
Has thanked: 0
Been thanked: 0

Re: Bottle Rocket B

Post by Littleboy » April 17th, 2011, 5:25 am

All that really matters in fins is that they are light, rigid, and don't have much drag.
What times are you all getting?
We tested a couple new ones yesterday. 35 mph winds with 50 mph gusts. They first one went up about 100 feet only because of the wind and then drifted a few hundred yards. And still was only 12 seconds :(. It was still good and backslided nicely. The other one we launched at exactly when a huge gust came so it went right to the ground. We will fly both again when we get the chance.

Cheesy Pie
Member
Member
Posts: 594
Joined: January 29th, 2011, 4:34 pm
Division: Grad
State: MI
Has thanked: 0
Been thanked: 0

Re: Bottle Rocket B

Post by Cheesy Pie » April 19th, 2011, 8:19 pm

Make a weather-flexible rocket.
100% of deaths are somehow caused by science.
Don't be a statistic.
Don't do science.

Naperville Central High School '17 :arrow: Michigan State University Physics '21
GO GREEN GO WHITE

User avatar
fishman100
Exalted Member
Exalted Member
Posts: 478
Joined: January 28th, 2011, 1:26 pm
Division: Grad
State: VA
Has thanked: 0
Been thanked: 0

Re: Bottle Rocket B

Post by fishman100 » April 20th, 2011, 1:29 pm

How would one do that?
Langley HS Science Olympiad '15

Cheesy Pie
Member
Member
Posts: 594
Joined: January 29th, 2011, 4:34 pm
Division: Grad
State: MI
Has thanked: 0
Been thanked: 0

Re: Bottle Rocket B

Post by Cheesy Pie » April 24th, 2011, 8:48 pm

Like, it won't get affected negatively by wind or rain. Or at least not much. You can't expect a good score if you launch any rocket into a tornado. And I can't explain because I know to do this because we built a rocket incompatible with wind that failed due to wind.
100% of deaths are somehow caused by science.
Don't be a statistic.
Don't do science.

Naperville Central High School '17 :arrow: Michigan State University Physics '21
GO GREEN GO WHITE

MVStangs
Member
Member
Posts: 3
Joined: April 4th, 2011, 7:47 am
Division: B
State: IA
Location: Wouldn't you like to know?
Has thanked: 0
Been thanked: 0

Re: Bottle Rocket B

Post by MVStangs » April 25th, 2011, 7:48 am

I just made a rocket that weighs about 153 grams with everything on it. I know that lighter rockets are good, but how light is too light, meaning how light would it have to be to not go up enough to get a good time?

Locked

Return to “2011 Build Events”

Who is online

Users browsing this forum: No registered users and 1 guest