Bottle Rocket B

[quizbowl]

honest question: what is a backslider, and how does it work?

[robotman]

A backslider is a type of rocket where you balance the weight of the top and bottom so that it will be launched go up and "slide" back down on its side
Youtube search
Decent Video

[fleet130]

what is a backslider, and how does it work?

See Robert Youen's bottle rocket page. He's not updating it anymore and some of the links are broken, but it still has some good info.

[scifipi]

For my school, this is our first year of bottle rockets and I get confused easily. I know I should do my research, but is there a basic summary of the event? I would be grateful for help.

[Littleboy]

Read the wiki. It is great help for beginners

[fleet130]

While browsing the internet today, I came across, what seems to be a fairly comprehensive water rocker website: Air Command Water Rockets. I only spent about 10 minutes checking it out, but it seems pretty good at first glance.

[asianboii]

I have 2 questions: Can you use a backslider? What would be a good height and width for the rocket?

[Littleboy]

Yes you can use a backslider It does not deploy You will have to experipent with height and width. All designs need different sizes

[Bacteriophage]

hey guys, im doing BR for the first time and was just wondering, where did ya guys get your launch pads? are the launch pads @ the competition PROFFESIONAL air compressors or just a bricolage of homemade junk ? what do u reccomend we use to test it?
and what if the rocket falls onto a tree? does r time stop there?

[AlphaTauri]

Quality of the launchers will likely vary from competition to competition (most places will probably reuse last year's Egg-o-naut launchers). Still, launchers at comp should work decently well, considering I was able to build one (based off of this design) with about $50 worth of stuff and a couple hours.

As for your second question, the rules say and I quote, "Timing begins when the rocket separates from the launcher and stops when any part of the rocket touches the ground, goes out of sight [probably added because of Solon's amazing 10-minute flight at Nats last year], or comes to rest on an obstruction (e.g., a tree or building)." So yes.

[rocketman1555]

Many competitions have professionally made launchers, but they are not necessarily the most expensive launchers, and most just use a bike pump to pressurize the bottle. I have an Aquaport Launcer Nerds Inc Launcher. Both work well, although I have had a little trouble with the aquaport launcher. It is definitely cheaper to build your own though.

[disownedpear]

what is the most powerful motor

[andrewwski]

You're not using a motor. It's a mixture of pressurized air and water that you're using to propel the rocket.

I found making a pad a few years ago was easier than I expected. I got a length of 1/2" Sch40 PVC (I believe, it's whatever the size that just fits in the bottle) and heated it over a Bunsen burner on very low heat (candle would likely work too) until it had softened. Then I slightly pushed the piece in compression so that it bulged a bit. This proved to make a good seal with the bottle when placed on tightly. I put a 90 degree elbow in and attached the tubing to a piece of pipe. I took a cap for the pipe and drilled it out so I could fit a tire valve stem in, and then attached it to the end of the PVC. Then I took a piece of 2-1/2" PVC and mounted it around the 1/2" so that the rocket could sit in it. Drilled a few holes right above where the bottle's flange was and put a nail on a string. Total cost had to be less than $15.

At the competition though, they had a nice launcher that was purchased, with a nice release mechanism and a detachable seal for the bottle so you didn't have to tip the pad every time you mounted the rocket.

It doesn't matter what you use to pressurize the rocket, as long as you have an accurate gauge. You could put a gauge in line with your launcher if you don't have a bicycle pump or air compressor with a decent gauge.

[5asdffdsa5]

how much water works best

[AlphaTauri]

I've heard that filling the pressure vessel (read: plastic bottle) about 1/3 of the way with water works the best, however, I haven't personally experimented much with it.

I strongly advise you to test it out yourself, as different rockets may work better with different amounts of water.