Has Anyone Built a Water Bottle Rocket + launcher?

Adamc

Has anyone built a water rocket and launcher similar to those common in America? I'm looking for some tips.

Many thanks 

daivid

No, I've only made simple friction launchers from wine corks, but this may help https://www.youtube.com/results?search_query=water+rocket+launcher+build+

Neil_Jones

Adamc said:

Has anyone built a water rocket and launcher similar to those common in America? I'm looking for some tips.

Many thanks 

For what exactly?  What end effect are you trying to achieve?

In its simplest form you just need to put some water in the bottle, secure a blockage in the lid area relatively securely (not totally), get some air into the bottle and when it can't hold any more pressure pops the lid off, forces the water out and up goes the rocket.

http://www.bbc.co.uk/bang/handson/waterbottlerockets.shtml

IvanOpinion

That take me back to my childhood.  I can't even remember what concoction of chemicals we used

chrisw

IvanOpinion said:

That take me back to my childhood.  I can't even remember what concoction of chemicals we used

Baking soda (sodium bicarbonate) and vinegar. The reaction's a bit unpredictable and you tend to get sprayed with vinegar but plenty of guides on the internet.

Mickey666

No need for chemicals if you use a compressor.  I've built water rockets using 2-litre drinks bottles and pressurised them with one of those cheap compressors used to pump up car tyres.  It can get a bit addictive if you have any 'nerdy' tendencies when trying to maximise the height or range - which can easily be 75m or more. 
There are calculators on the web to work out the optimum amount of water for a given volume of the bottle - too much water means a heavier rocket but a longer thrust time, too little water means a lighter rocket but less thrust time.  Pressure also make a difference, obviously, as does streamlining and fins for stability.  Lots of factors to trade off in pursuit of the optimum combination.  There are even designs online for multi-stage water rockets, though I never did get that far.  Anyway, loads of info online.  Here's an example video: https://www.youtube.com/watch?v=0qzOzjRJpaU

forgotmyname

Done both those, tablespoon of bicarb wrapped in a tissue, put some vinegar in the bottle and the tissue gives

you a few seconds to get the cap on. Don't remember smelling of vinegar but thats probably my memory

rather than not actually getting covered.

I had a rocket for xmas which came with a small pump like the ones used for balloons, put water into the rocket,

place the rocket onto the pump and slide a catch across, pump and then slide the catch to release.

Should be easy enough to replicate that, lip on the neck could be used to retain the bottle onto a pump.

What skills do you have and what parts do you have to hand?  Drill the cap to accept a rubber tyre valve

and use a bicycle pump or car pump to inflate and release?

IvanOpinion

chrisw said:

IvanOpinion said:

That take me back to my childhood.  I can't even remember what concoction of chemicals we used

Baking soda (sodium bicarbonate) and vinegar. The reaction's a bit unpredictable and you tend to get sprayed with vinegar but plenty of guides on the internet.

Yea, that rings a bell, but I also remember using something a bit more 'toxic' - it came from the garage rather than the kitchen.  
PS: Yes I do remember being sprayed regularly