How to make a nosecone?

[Tommy]

I need to make a nosecone for my increasingly larger rockets, and I can't think of anything. I know about the ping pong ball idea, but that requires a different bottle with a top that tapers more than any I can find. I was thinking about cutting off the top and using and inflating a balloon inside, but I am not sure if the air pressure will push the balloon down.

[Azriel]

Maybe try a part of a plastic easter egg? The balloon will likely be pushed down by air pressure, and even if not, it will need to be frequently replaced

[U.S. Water Rockets1]

Maybe try a part of a plastic easter egg? The balloon will likely be pushed down by air pressure, and even if not, it will need to be frequently replaced

We buy a couple of bags of those plastic eggs because they fit really well and match the curve of the 2 liter pepsi bottles. The biggest size eggs are the ones that we use the most of.

[rockets-in-brighton]

If you want a quick nosecone, use two bottles the same size as your pressure vessel. With one bottle first cut off the base. Then chop off the heavy neck section, leaving a round hole. Fill the hole with a patch cut from a curved section (near the transition between sides and neck) of the second bottle. You can use epoxy or contact adhesive or superglue - it doesn't need to be airtight. Works best with round-shouldered 2 litre bottles, rather than straight shouldered 1 litre. Tape the finished nosecone onto your pressure vessel.

You can also use this nosecone as a mould for a papier mache nosecone, which if made carefully could be lighter if not stronger.

[rockets-in-brighton]

I forgot to say that for starter rockets the exact nosecone shape is not critical, it is more important that it should be a smooth surface without sudden changes in shape. Hemispherical is fine but you can also get away with simple conical noses, which can easily be made from light card.

[Rocket Bob]

If you put a rubber valve stem in a bottle cap ( easy).
Screw it on a bottle.
Pressure-ize to 15 psi ( give or take 5 psi).
Then place a heat gun on the work bench and
heat up the tip of the bottle WHILE you rotate it,
with a bit of practice, you will blow a beautiful
nose cone. Easy, quick. The local tire shop will give
you a valve stem if you ask nicely and tell them of your
project. This is my standard technique.

RB