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

[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.

[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!

[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!

[cyenobite]

Cool bottles! Practically speaking, I would choose the "bilbor" as it would be the smoothest, and probably very aerodynamic. But I really like the shape of the "red one" (middle), for design reasons that one might "look" really neat, but it would be tough to have the fins conform to the shape of that curved bottle. The Borteni, has a sort of flat top, that probably would not be as good aerodynamically.
Good luck!
PS> While I like the shape of the red bottle, I wonder if it's made for the pressure you'd be putting into the bottle. Since it's made for water, it might not be designed to hold the pressure. Where-as Soda bottles are designed to hold the pressure from the carbonation. Something to keep in mind.

[cristeaudar]

Hi, it's done, here are the photos. By the way I came in first for design and flight!

[cyenobite]

Fantastic! Grats! I don't see a link though on where the pictures are - curious to see how it looks! Thanks for posting the follow-up.

[cristeaudar]

oh, sorry there you go : http://imgur.com/a/ugmtW#0

[cyenobite]

Looks great! Nice paint!

[cristeaudar]

Well i chose carbonated water bottles because in my country those are made of the same plastic thickness of sodas. Thanks for your advice! I'll tell you if I win!

[ejojo]

Hey I've a bottle rocket design competition coming up.
Can I use this idea? I'm a novice in design stuff. I've to hit the target at 15 to 20m away.Will it work?
Reply soon plz!
Thank you!

[cyenobite]

Hi Ejojo, I'm not sure I understand your competition of "hitting a target 15-20m away". This design might work for that, but it may take a lot of practice launches - the rocket I don't think is accurate enough to be able to hit a target, there are so many factors involved (wind, pressure, amount of water, etc...) - but feel free to modify this design as you want. Good Luck!

[ejojo]

Oh okay thanks for replying!
I think I'm going to make this rocket and try....
And oh I'm honestly just trying myself for this competition.Designing has never been my brain's love.That's why I'm afraid =(

[he who crashes often]

but designing is so much fun!

[ejojo]

Designing is fun, yeah.
And the science behind designing is made easier by Instructables :)

And my rocket had the craziest flight in the competition!
I won the bast poster design though. Cheers!
ReplyFeature Commentflag[delete]

[BluePhenox]

would hot glue work for the fins? Because I don't want to have my fins breaking off.

[J19]

you should use epoxy it on gets a couple of degrees hotter but not as hot as a hot glue gun and it holds better because it gets hard not rubbery like some hot glues

[he who crashes often]

i disagree. rubbery glues can be excellent as they can "give" somewhat in high-impact situations (such as... oh, i don't know, landing?) and prevent breaking. i use hot glue on my r/c planes, some of which weigh over 20lbs. i had a 12lb ducted fan jet hit the tarmac after losing control and diving from 90 feet up. the epoxy had all snapped, and the hot glue had just gone "boing" and stayed strong. if i had used epoxy everywhere it would have been much harder to fix.

[danieljw]

i yoused hot glue to glue pens to gether and the pens melted so be careful.

[dmcclellan]

hot glue could weaken the plastic. Use very low temp glue and be careful not to melt holes into the bottle.

[tigon134]

YES........... :D

[thats mr sonic to you]

yes it would when i made my rocket it worked

[cyenobite]

You can try it - but in my opinion Epoxy is a much stronger bond than hot glue. Also, if you're using the "foam core" the hot glue might melt the foam. I thought of using it too - it's defintely easier than Epoxy - but I went with the Epoxy because like you, I didn't want the fins breaking off. My rocket survived a crash into a tree, and several nose dive landings.
Good luck. If you do go with the hot glue instead, post back here as to how it worked for you.

[ilpug]

hot glue wont damage foam core too much. i use it on it all the time. i plan to make this rocket that way.

[cyberviper42]

I would recommend not using a dark color for your rocket. Black is probably the worst because it will absorb the sun's heat and potentially warp the rocket enough to make it fail according to murphy's law.