Compressor question

explosives work better!

Regards Richard

you can easily make a similar rocket out of a P.E.T. bottle and the valve cut out of a bicyle tyre inner tube.

take an old inner tube and cut out the valve stem, leaving a bit of the tube around the base (you need this to help make the seal)

cut a hole in the screw on cap of the P.E.T. bottle big enough for the valve stem to fit through, put a bit of silicone between the rubber and the cap to make a decent seal.

fill the bottle with 1/8th of water, screw the cap on and hook up a bike pump. Pump it up as hard as possible and then detach from the pump and slowly unscrew the cap, making sure you point it away from your body and not at anyone else.

the bottle should shoot up into the air to a reasonable height.

I need one, lets get a cartel together and order many at a reduced price.

If you sat on it you could be in the next dumd ass movie :-)
I rekon about 2 minutes of fame and a life time of pain!
Niffty
Perth

Do the bottle rockets at the local school fete every year.
Generally get 20 to 30 metres with a 1 litre soft drink bottle.
The kids use hand pumps though.
The secret is to pump slowly and steadily until it goes.

For the cork, we put an old tyre valve stem through a rubber cork, and push the cork into a 1 litre soft drink bottle.
1 to 2 cups of water gets the best result.
Too much water and the intial acceleration is less.
Harder you push the cork in the further it goes once it lets go.
(Little secret, great fun when the littlest kid there gets an extra push on the cork, and all the bigger kids get beaten :o), tis a pleasure to see the smile of success at beating all the others , the ones who normally beat the little kids at most things.)

1 litre bottles go further than 2 litre bottles, less air resistance, since the bottles fly 2/3rds of the distance empty.

Yes, when we made up the rockets, my mate and I had to, in the name of experimentation, fly rockets all afternoon to find the best combination.
The wives just called us big kids and left us to it.

So the answer is, the size of the pump doesn't make any difference, if anything, the slowest one may produce the best distance.
Watching the pressure guage, it is hard to find a cork in the soft drink bottle that will go much beyond 50 psi before letting go. Found rubber corks worked the best.

Now, of course you will need to build a rig and experiment to prove me wrong!

I'm more into nitrous oxide versions , but brother had home made one at Xmas camp. Using 1.5m Electrical conduit main tube and pumped to 100psi with arb compressor and about 900ml water.

It sure went straight up but only about 20m.

Robin Miller