Combustion Water Bottle Rockets

[mark.f]

Just after firing, are you shaking your hand dry or did it hurt you?

Dry. Did the sloopy arm appearance give you the impression of a fracture?

I've been playing around with a few crude combustions (ignition circuit testing) and I'm rather suprised with the power.

What I have been trying to tell many people since I first started.

[jackssmirkingrevenge]

Dry. Did the sloopy arm appearance give you the impression of a fracture?

[Insomniac]

Haha did anyone else think that in the .GIF it looks like he's turning on a lightsaber?

[Lockednloaded]

On average, how high/how far do they go?

[mark.f]

There's no telling. I suppose I could rig up an "angle finder", but then I'd need to rig up a way to remote launch it.

[Lockednloaded]

just a rough estimate, or distance would be fine

[mark.f]

Well, distance is out, as firing horizontal allows gases to escape without forcing the water through the nozzle.

As far as a WAG for height, I would say maybe 50 feet. Hangtimes really aren't that reliable because of how the bottle flies, but in the video, you can hear the bottle land towards the end.

EDIT: about a 4 second hang time with just a plain bottle. However, my revised rocket shows promise.

[Secret Squirrel]

I just tried this out. It took less than an hour to put together from junk in the garage. Cheap, quick and fun. The bottles don't go particularly high, but who really cares? It's practically free.

[jimmy101]

http://www.et.byu.edu/~wheeler/benchtop/pumpkin2.php

[mark.f]

Ah, and we see again nothing is new is the world of... well, everything.

He should be getting much better height using hydrogen and oxygen over just propylene or propane in air. However, I don't have the nerve to be launching such mixtures by hand.

[warhead052]

What I mean is that, if I were to place the "bulb" at the neck of the 20 oz. bottle to where the spark gap was at the very top of the rocket, if I switched to a 2L bottle, the spark would be lower. I'd also like to see if there's any difference between a centrally located spark and a spark at either extreme end of the "combustion chamber".

Then you simply use a coupler, and a couple alligator clips and wires, and have a extended rod. No big deal, it works excellent for me, with air pressure atleast...

[mark.f]

Then you simply use a coupler, and a couple alligator clips and wires, and have a extended rod. No big deal, it works excellent for me, with air pressure atleast...

First off, that effectively blows my budget of approximately $0.00 & 0/0 USD. As I said before, it doesn't leak any detectable amount, and with the bottle in the inverted "firing" position, even minuscule leaks are leaking water, not the ever important fuel mixture.

In other news, I left a rocket "charged" (filled with the correct amount of water, fueled up with the torch, and then capped off) for a full 24 hours, shook it up, uncapped and mounted it on the launcher, and fired it off, no problems. Thinking of making an ammo belt.

[warhead052]

Ok, well, its worth a shot when you wanna spend cash on it! Believe me, it works, and its a fun airsoft rocket launcher too...

[mark.f]

Trust me, when I have cash to spend, I'm not wasting it on bottle rockets.

(I'm going to waste it on gas, insurance, school, first...)

[mark.f]

So... horizontal launches...

I tried this off the page Jim linked earlier in the thread, but obviously modified slightly to work with combustion. All I did was run a pair of wires around the balloon. Inconsistent fueling and popping balloons are plaguing me.

So, does anybody know a simple, safe gel that could be used for the same thing? I tried using cornstarch and the microwave, but got lumpy gels that don't really stay together.