Soda Bottle Water Rocket

In a couple of hours (or less) you could make this water rocket! Water rockets use water and pressurized air to launch a soda bottle(s) 100's of feet into the air. This instructable will NOT cover the launcher. I hope to later come back and write up an instructable for a launcher. There are many websites with water rocket plans (and launchers) part of the fun is to experiment and come up with your own designs. Feel free to modify, improve, experiment with this instructable and post your results in the comments. The original inspiration for this rocket was from the magazine called "MAKE Magazine" (makezine.com). Issue #5 has full instructions also.

Step 1: Materials

List O Materials...

> 2 Soda Bottles (empty)
- Note: There are slight differences in the openings of the bottle depending on the soda brand. Pepsi is just a tad smaller than Coke. -
This Instructable is set up for 2 liter sized bottles - feel free to adjust for any size though.

> 1 sharp knife (kids get your parents help here!) I prefer X-acto brand for cutting foam core.

> 1 Large sheet of Foam Core (I prefer Black, but any color will do). Foam Core can be found at almost any arts and crafts supply store. To learn more about foam core try wikipedia: http://en.wikipedia.org/wiki/Foamcore

> 5 Min Epoxy (This stuff is nasty! Do not inhale, and use in a well ventilated area. Do NOT get it on your skin or eyes, or hair, etc... read all safety warnings before using.) Feel free to experiment with other glues. This can usually be found at any hardware store - kids, ask your parents for help with this glue.

> 2 (or more) Markers - I used Sharpies, one black and one Silver

> Clear Shipping Tape - It's thicker than regular scotch tape and about 2" wide.

> 2 (or more) cans of spray paint - Pick your own favorite colors!

Comments

[reslami]

how would you use the foam core and the 5min epoxy is my question? And also what would you do to make a nose cone for the rocket.? please message me back I would really be thankful.

[chocolatelover]

how much water (in cups or milliliters)? PLEASE ANSWER i have to launch my rocket tomorrow at school and we have to know and bring how much water we need and i cut the bottle that goes on top way shorter than yours i also used coca cola bottles just wondering if that affects the amount of water needed PLEASE ANSWER and THANK YOU!

[cyenobite]

I answered this below - but because I'm nice I'll repeat it here... About a third of the bottle. (hint: if you bring one 2 liter bottle of water with you, you should be able to get about 3 launches). Hope that helps :)

[freelancersoleil]

I've found sprite bottles work very well with this project

[AwkwarddAri]

I'm doing this for a science project :) I'll share my results soon! :D

[MrBlobby123]

Amazing absaloutley flabergasting

[M40A3 Dsx]

very helpful thank you

-M40A3 Dsx

[Schober]

There is a way to splice the two bottles together so that you get an increased pressure chamber instead of having the other bottle being just dead weight on your rocket. Be advised this does take much more time and is far more costly than simply attaching the other bottle, but it seems to me like it would be worth it. I did not make this video I'm simply sharing it with the people.

[paperclip32]

I think getting all the materials to do that would cost too much.This is just for kids,anyway.

[Jaygo]

Actually, if you look, most of that stuff can already be found in any average house hold. Under "What you will need" I see, a ruler, scissors, razor knife, stapler, duct tape a stick, and construction adhesive. While not uncommon, if a 'razor knife' is not available, just about any sharp knife will do.
I would think that abut the only thing most people would have to buy would be the construction adhesive (and we have that too).
Now I would say with the knife and using the stove and hot water, this would most definitely call for adult supervision to be on the safe side.

[epic sonic]

ever thing is cheap except for the foam core

but you can buy it at the $Rama for $2.00 but then its not as good as if you buy it at

staples

thanks for your time

[paperclip32]

I was referring to the video Schober posted.

[scottington]

Would a nose cone work. Im doing a thing for school that it has to get 20% further than a stock-standard 2L coke bottle. Will this work without a nose cone or with?

[THEFORREAL]

Heating the Water will increase pressure but This is Dangerous you must make sure you or any small children do not get burned . Also there is a Rocket you can make useing Sodium Bicarbonate ( Baking Soda) and Vinegar .There is a video on YouTube. www.youtube.com/watch?v=WtUBFc9Gz_U

[THEFORREAL]

Try adding Soap or Joy(Dishwashing Liquid ) to the water .I Saw another website online that sais adding soap to the water would increase Thrust duration. Try shaking it up so it Foams a Little. Another goood site is:
www.microgravity.grc..nasa.gov/education/rocket/BottleRocket/journey101test.htm

[cyenobite]

Hello scottington,
As you can see from my instructable and the video at the end, I did not use a nose cone. It worked ok for me. But you can certainly try it... it should help the rocket go further as long as it is not too heavy. A word of caution - a nose cone will make this rocket dangerous with a sharp point on the front - be careful and be sure to use with proper supervision. Also, my rocket/instrucatable does not use a parachute... if you want your nose cone to last for more than one launch you might consider a parachute, otherwise it will probably get damaged on the first launch. Good Luck!

[THEFORREAL]

Why do You need Water to make it work ? Shouldn't it work with Only the Pressurized Air ? Compressed Air cylinders have been known to go through Cinder Block walls. I am really interested and hope to build one of these Waer rockets. Thank You all for Contributing/Sharing Tips and Ideas.

[cyenobite]

That's a good question. I'm not a physics person, but I can venture a guess... Yes, air can propel a bottle, but it takes a LOT of pressure. The ones you saw going through cinder block walls have a ton of pressure. All that pressure is able to propel the metal canister. The same thing with a balloon... you blow up a baloon and let go and it will fly all over the place, but that's because the rubber of the baloon is very light. A PET (plastic) soda bottle is very heavy compared to the balloon. By adding the water, it gives the air something to "push" off of rather than the outside air around it. Because of that push from the water, it's able to propel the heavier plastic bottle.
Don't take my word for it, I might be wrong. Try to find a science teacher and see if they can explain it better than me. :)

warning: the plastic soda bottles are only built to hold a certain amount of pressure before they will explode (or break). Do NOT attempt to put a lot of air pressure into the plastic bottles.

[nuts900]

how do you luanch it

[allensu0]

Hey! I like your rocket and i think it's pretty sick. Do you have any tips for distance. cuz i have to make a water rocket for engineering, and we're only getting marked on how far our rockets go.

[cyenobite]

Hey Thanks @allensu0
No real tips for distance other than you should experiment with how much water to put in. Too much, and the rocket is too heavy, too little and it runs out of propellant. If you can get some test runs in for your rocket that'd be best. I found that about a third of the bottle works well. Another option is to get rid of extra weight - maybe experiment with lighter or smaller fins? Good Luck!

[stumitch]

i've built 100's of these with my students... its a great project. what i have found is that weight is actually a GOOD thing! i encourage students to use ballast.... nothing hard which can be lethal.... stuff like water balloons, bags of sand or heavy cardboard tubing or the "eggstranaut" which is an egg in the nose section. if it survives the students get extra marks. :-) i've had kids rockets speck out in the sky with 100psi at the compressor output. if you crank the psi they can explode but man if they fly it is really impressive!

[acdc1226]

Yesterday Me, my brother and my dad made an awesome water rocket from a 2L soda bottle and a bike pump. We used plans from a Popular Mechanics online article. It cost us about $15. It easily flys 100ft.

[nuparu106]

For this step, would it still work if i use duct tape? My teacher suggested that we use duct tape instead of shipping tape.

[cyenobite]

Duct tape would certainly work, but in my opinion the clear plastic shipping tape is: 1) much lighter than duct tape and 2) much smoother and easier to paint over. If applied carefully you won't get any seems or bumps. If you don't care how the rocket looks then duct tape will be fine. Good Luck.

[nuparu106]

Thank you. the rocket was successful, thanks to your advice and design!

[cyenobite]

Awesome - glad to hear it worked out well for you.

[bballer23]

hey that design was awesome an the instructions were clear and understandable. for school i have to make a rocket that has to stay in the air for 15 secs and launch an egg and make sure it doesn't break. what would you recommend for this?

[cyenobite]

This may not be the best design for the egg challenge. First off, 15 sec is a long time! If you watch the video at the end of this instructable you can time the rockets and their air time. I'm pretty sure these water rockets are not in the air that long. Also the weight of an egg along with any padding are going to weigh this design down a LOT. I'd suggest you check with your teacher and see if the water rockets are what he or she had in mind. Good Luck!

[jalin9]

For some reason our school has asked that the fins don't go beyond the fat part of the bottle. Would the rocket still work if I moned the fins up on the bottle?

[cyenobite]

I seriously doubt that it would work. I can't understand why they would require such a strange rule. I would double check with a teacher to see if that is correct, and if it is, get a science teacher to explain why this is a horrible rule when it comes to designing and rocket construction. If your science teacher is the one who came up with the rule, then it's time to find a new science teacher :)
Good Luck!

[hlim2]

Hey ! That a nice and simple rocket !
I have a competition on this wednesday. so I decide to use this method to make My rocket .
But I have question.
Can I change the Min Expoxy to silicone sealant to attach on my rocket?
I hope you can reply as soon as you can ..
=)

[cyenobite]

@hlim2, Neat! I'm not 100% familiar with silicone sealant, but if I'm not mistaken, that's used more as a "caulk" and for weatherproofing, and it's not really meant to act as a glue. Silicone is usually flexible too, so I'm not sure if the fins would be strong enough. I would recommend a glue like material, but if you can't find any, go ahead and try the silicone.
Good Luck!

[hlim2]

Yo!
I just finished my rocket !
here have thelink to see my rocket: http://imgur.com/I0Cmb

[cyenobite]

@hlim2 - Well done! I like the idea of putting stickers on it too. I noticed your fins are very thin too, which means less weight probably and higher launch. Thanks for posting! Good luck on launch day!

[cristeaudar]

Hi, cristeaudar here, in 2 weeks i have a school water rocket competion and I could wonder if I could put 3 angled fins at the base to make it accurate and 3 little ones at the top for extra - portance using your design because it fits me the best. :)

[cyenobite]

Go for it! The only thing I would caution you on, is that possibly added weight of more fins might cause the rocket to not go as high, but if you keep them small, it shouldn't be that big of a deal. Good luck and post your results of how you made out! Good Luck!

[cristeaudar]

thanks for replying! Thank you for advicing, but I don't have soda bottles like yoours, do you mind if I send some pictures of the bottles I got and tell me which one is the best?

[cyenobite]

Sure, post them to the web and I'll take a look. Use a site like flickr or http://imgur.com/ and post your link back here when you're done.

[cristeaudar]

Done. Here's the link : http://imgur.com/a/XG035
Choose the best one!