Hello - and some nub questions..

This forum is for new members to introduce themselves and tell us how they got started in water rocketry.
afrosonic
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Hello - and some nub questions..

Post by afrosonic »

Hello all; you have a great board.

I’d like to get started on my own project as soon as possible and was wondering if someone could help me with some newbie questions. I admit I didn’t spend as much time as I should have searching the forums; also, I apologize if I come off sounding stupid. However, I would greatly appreciate any help at all.

That being said, can (or, why can’t) I use extra energy stored in pressure vessels fixed to the ground in addition to water/air in the rocket? In other words, can/why can’t I build some kind of water cannon to fire the rocket before the rocket itself ignites?

If I want to add boosters to my rocket, why (or why not) should/shouldn't I combine the output of all the boosters into a single nozzle? Would such a setup be easier than building a simultaneous firing rig?

Also, is it possible to point the boosters towards the rocket’s CG (similar to the Soyuz)? Would such a setup help constrain the rocket to translation rather than rotation during the booster phase? And, what factor, if any, would that play in eliminating problems caused by differences between each booster’s ignition time, thrust and burn time?

Any help would be greatly appreciated.

Thanks,
A.S.
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Nick B
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Re: Hello - and some nub questions..

Post by Nick B »

"That being said, can (or, why can’t) I use extra energy stored in pressure vessels fixed to the ground in addition to water/air in the rocket? In other words, can/why can’t I build some kind of water cannon to fire the rocket before the rocket itself ignites?"


Just use 100 feet of copper tubing and industrial air compressor hose with your launcher.... RO:


:W
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WRA2
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Re: Hello - and some nub questions..

Post by WRA2 »

afrosonic wrote:Hello all; you have a great board.

That being said, can (or, why can’t) I use extra energy stored in pressure vessels fixed to the ground in addition to water/air in the rocket? In other words, can/why can’t I build some kind of water cannon to fire the rocket before the rocket itself ignites?

If I want to add boosters to my rocket, why (or why not) should/shouldn't I combine the output of all the boosters into a single nozzle? Would such a setup be easier than building a simultaneous firing rig?
Welcome to the Water Rocket Forum :W

The reason that external ground based assistance is not allowed is that the competition would become "who can build the biggest (and most expensive) ground assist device". This keeps the competition fair to all.

A single nozzle combining the outputs of several "bottles" would be allowed but the trick to making it work would be making it light enough.
Lisa Walker,
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Brian
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Re: Hello - and some nub questions..

Post by Brian »

Hello!
afrosonic wrote:That being said, can (or, why can’t) I use extra energy stored in pressure vessels fixed to the ground in addition to water/air in the rocket? In other words, can/why can’t I build some kind of water cannon to fire the rocket before the rocket itself ignites?
If you are able to make a cannon, do so. The only thing you can't do is enter it into the competitions here as they are for rockets only and not cannons.
afrosonic wrote:If I want to add boosters to my rocket, why (or why not) should/shouldn't I combine the output of all the boosters into a single nozzle? Would such a setup be easier than building a simultaneous firing rig?
Because it is better to make a long and thin rocket due to less drag, the main reason for making boosters a few bottles wide is to add more nozzles for more power. Because boosters need more power to carry the sustainer more nozzles is better than one.
The choice is between a simultaneous firing rig or a network of pipe from the boosters.
afrosonic wrote:Also, is it possible to point the boosters towards the rocket’s CG (similar to the Soyuz)? Would such a setup help constrain the rocket to translation rather than rotation during the booster phase? And, what factor, if any, would that play in eliminating problems caused by differences between each booster’s ignition time, thrust and burn time?
This setup would probably be more stable but it is alot easier to point all the boosters vertically than at exact angles. The little time the booster operate in leaves little time to roll. Also the extra drag of the booster will move the CP back to help keep it stable.
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afrosonic
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Joined: Sun Sep 13, 2009 10:22 pm

Re: Hello - and some nub questions..

Post by afrosonic »

Thanks for the input. I can appreciate the members' purist philosophy. It's like asking why can't I add solid rocket boosters to my water rocket - the answer is *you can* - but it's not a *water* rocket.
afrosonic
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Re: Hello - and some nub questions..

Post by afrosonic »

BTW, Thanks for all the warm welcomes!