Can I use potato cannon to launch a [water] bottle rocket?

[eafindme]

Hi, everyone.
I am taking part in [water] bottle rocket launcher recently. Other than water as the propellant, I have no other replacement. I think if I launch the bottle rocket in other way, like the potato cannon, this will be more creative and more fun.

My idea is like these:
When the aerosol inside the combustion chamber is burnt, the pressurized air will propel the potato and the potato propels the [water] bottle rocket at the same time.

Can anybody give me some comments? I do not sure whether this launchig mechanism will works or not.

[Edited by Gort. 03-07-09 1940 Central]

[inonickname]

Well I did begin to build a pure ftc based launcher with a reduced nozzle, launch tube and an exterior tube that is a very close fit to the ftc. The release mechanism was fitted with a lever that swung through 90 degrees. At around 40 degrees it opened a sprinkler (actuated a blowgun) valve to the injector, then at 90 it released the rocket. This gave it the boost of a pneumatic ram from the inner launch tube, the ability to use a large amount of ballast, a reduced nozzle and the effect of a spudgun from the outer tube. It will be completed as soon as I can find an exterior launch tube.

I wouldn't bother really, unless the rocket is extremely uniform you will see little to no benefit. Your mechanism must be releasable from the outside, but still airtight.

A very difficult thing to do.

By the way, FTC = flourescent tube cover

[eafindme]

Oh, you means directly use the pressurized gas to propel the bottle without using the traditional heavy duty air pump?

If so, I will add a launch tube at the nozzle of the combustion cannon and launch the rocket (with water inside) as normal. The only differences is the pressure and no release mechanism, right? [/quote]

[inonickname]

You still use a pump/compressor/air cylinder. Except with this design you pressurize the rocket chamber, and a secondary chamber mounted to the launcher. When you pull the launch release which is synchronized with the secondary chamber it dumps air underneath the bottle, then the rocket is released. This gives it a massive amount of energy from the pad (in theory I suppose).

[eafindme]

Pressurize the aerosol and burn it as the bottle rocket is released? Don't the water bottle will burst?

[sgort87]

Edit:

Forget I said anything. ("Bottle Rocket" means something different to me than some I guess.)

[PCGUY]

So I am guessing you don't mean a fireworks kind of bottle rocket right?

[sgort87]

He means a water rocket in a bottle. That's what I thought at first.

[inonickname]

Yeh, the term "bottle rocket" should really only apply to the wasting of solid fuel motors. Water rocket is a better term and then there's no misunderstandings.

What your basically describing is using a potato as a wad. Better to justuse a rag or you'll be limited on size.

Also consider something like this:

Hydrogen launcher

Though I'd use propane for portability.

Edit: wrong launcher.

[jrrdw]

Yes this is badly worded. So is the title.

@eafindme, read the rules and you will relize what we are talking about.

[eafindme]

No, a bottle rocket which is filled with water (pressurize the air space inside the bottle which will force the water to spill out at high speed as soon as it is released)
http://ourworld.compuserve.com/homepage ... tindex.htm

Anyway, u means use the aerosol and the combustion chamber as the secondary propulsion so that the rocket can gain more energy and fly higher ?

[eafindme]

But that is OK, not dangerous game.... and thanks for your remind, I'll keep in eye on the rules for the next time.

[inonickname]

Presuming adding this link is within the rules:

Bottle rocket.....

You could wire the sparkgaps in series, one inside the rocket (propane air mix in the rocket) and one underneath (propane air mix under rocket) for extra power. Pneumatic would still give more get up and go, but propane would make it incredibly portable.

Edit: no need to double post, unless your pretty much out of room on the last post (eg. pictures) or there's some other reason. Most people don't care, but some will get quite upset.

Just keep it in mind man (remember the edit button)

[eafindme]

OK, I'm not so well in English, maybe I dont know what is bottle rocket before that. Thank for your information. Not bottle rocket, but water rocket.

[eafindme]

And thanks for all your reply. I'm more understand on how to build a better water rocket launcher. I'll try it and posts my successes.