My water rocketry "wish list"

[The Sky Dart]

Anticipating Christmas, New Year and all that, I've put together my water rocketry "wish list". I'm posting it here as, I hope, someone may find some of my ideas interesting and inspiring enough. Besides, it's very unlikely our team will be able to investigate all ideas. Anyone is welcome to help us.

1) Further development of a configuration where a high pressure motor separate from a rocket itself in a way it's done in conventional rocketry.
The project we are currently working on is suppose to lead us into that direction and hopefully there will be some visible results next year.

There are several benefits of such approach:
• The same motor can be used for multiply rockets allowing easier experimentation with airframes, deployment system etc
• Easier recovery after unsuccessful launches
• Utilisation of technology used in constriction of conventional propylene rockets
• One motor can be shared by several people/ teams

All other "wishes" below are rooted into this idea.

2) Finding optimum manufacturing technique for motors. Distraction tests of different materials.

3) Utilisation of materials and techniques used in traditional rocketry.
Personally I don't like how water rockets made of bottles look like. Sleek streamline airframes have much grate appeal to me. I can't see why water rocketry should be devoid of

• Advantage of using light, cheap materials
• Traditional bonding techniques
• Significant Prefabricated spares such as body tubes, nose cones ets

4) High pressure motor build from "blue" tubes ( http://www.apogeerockets.com/blue_tubes.asp, http://www.rocketstore.co.uk/shop/prodt ... istory=cat )

For me this is probably the most interesting idea. These tubes can potentially revolutionise water rocketry. They can be a cheap alternative for reinforcing.

Lets have a look:

Blue Tube 98/48 ($38) , Weight = 725g,
ID=3.9" (99mm), Length = 48" (1216mm). Volume = 9.23L .
Price per 1L =38/9.23= $4.1 or 29/9.23=£3.1
Weight per 1L = 78.5g

Price and weight are about twice of these for traditional water bottles, but potentially :
• higher pressure can be reached (200-250psi)
• easier bonding technology can be used. These tubes do not require any special glues.
• No need for bottle splicing

Simple back-of-the-envelop calculation shows that a rocket build using such tube as a pressure vessel can teach about 200 meters or even more.

5) Further development of the currently used deployment system.
• Smaller and lighter flight computer
• Different materials
• Smaller and lighter battery

6) Utilisation of RockSim in the rocket design process.
I see a lot of potential in the tool for Wrocketry.

[rockets-in-brighton]

1) Further development of a configuration where a high pressure motor separate from a rocket itself in a way it's done in conventional rocketry.

I think once you start building your own modular rockets you get all kinds of advantages in mixing and matching parts between different rockets. However, unless you are just talking about your own personal rocket fleet, the idea of standardising across the hobby and allowing standard parts to be bought and exchanged instead of constructing bespoke parts as at present, that's not going to happen I think. A big lure of this hobby is the low barrier to entry because bottles are mostly scrounged from the recycling bin. So they are whatever size are locally available, and we build rockets around that size, and scratchbuild everything else to go with them. I know for me personally - and others I have spoken to - much of the satisfaction comes from building everything yourself.

WRA2 competitions implicitly support that view, under the various provisos that exclude purpose-built nose cones, fins and pressure vessels - but of course WRA2 is not the whole hobby.

2) Finding optimum manufacturing technique for motors. Distraction tests of different materials.

For me, this translates to perfecting a repeatable splicing technique working with the tools and materials I have available, and developing or adapting a robinson-style coupling.

3) Utilisation of materials and techniques used in traditional rocketry.
Personally I don't like how water rockets made of bottles look like. Sleek streamline airframes have much grate appeal to me. I can't see why water rocketry should be devoid of

• Advantage of using light, cheap materials
• Traditional bonding techniques
• Significant Prefabricated spares such as body tubes, nose cones ets

Yes, if there was a mass market for water rocketry we could buy factory-made bottles of any volume pre-formed in low-Cd aerodynamic shapes, with integral molded-in Haack nosecones. We could buy off-the-shelf dependable deployment/recovery modules that would neatly snap on to pressure vessels, with a table of values to refer to for setting the deployment time correctly depending on what modules we had selected.

Where would be the fun in that? ANd if you want to see beautiful home-made water rockets, go search for Batkiter.

4) High pressure motor build from "blue" tubes ( http://www.apogeerockets.com/blue_tubes.asp, http://www.rocketstore.co.uk/shop/prodt ... istory=cat )

For me this is probably the most interesting idea. These tubes can potentially revolutionise water rocketry. They can be a cheap alternative for reinforcing.

This is interesting. It seems to be a paper/card tube rolled tightly, as per traditional pyro rocket bodies, but the paper is impregnated with resin to strengthen it. I saw stuff about what pressure it could withstand, but I got the impression that that is instantaneous pressure not sustained pressure. Can it be made air/water tight, and can it hold pressure for long enough on the launch pad? One to watch.

5) Further development of the currently used deployment system.
• Smaller and lighter flight computer
• Different materials
• Smaller and lighter battery

I think you've got the right approach, get it working first then tart it up, make it lighter, stronger, better looking. I am impressed with your road-map approach to developing a water rocket - milestones give you something tangible to aim for, and something to celebrate when you achieve it.

6) Utilisation of RockSim in the rocket design process.
I see a lot of potential in the tool for Wrocketry.

[/quote]

Absolutely! See this article WARNING: links to a PDF http://www.apogeerockets.com/Education/ ... ter219.pdf

[The Sky Dart]

1) Further development of a configuration where a high pressure motor separate from a rocket itself in a way it's done in conventional rocketry.

I think once you start building your own modular rockets you get all kinds of advantages in mixing and matching parts between different rockets. However, unless you are just talking about your own personal rocket fleet, the idea of standardising across the hobby and allowing standard parts to be bought and exchanged instead of constructing bespoke parts as at present, that's not going to happen I think. A big lure of this hobby is the low barrier to entry because bottles are mostly scrounged from the recycling bin. So they are whatever size are locally available, and we build rockets around that size, and scratchbuild everything else to go with them. I know for me personally - and others I have spoken to - much of the satisfaction comes from building everything yourself.

WRA2 competitions implicitly support that view, under the various provisos that exclude purpose-built nose cones, fins and pressure vessels - but of course WRA2 is not the whole hobby.

2) Finding optimum manufacturing technique for motors. Distraction tests of different materials.

For me, this translates to perfecting a repeatable splicing technique working with the tools and materials I have available, and developing or adapting a robinson-style coupling.

3) Utilisation of materials and techniques used in traditional rocketry.
Personally I don't like how water rockets made of bottles look like. Sleek streamline airframes have much grate appeal to me. I can't see why water rocketry should be devoid of

• Advantage of using light, cheap materials
• Traditional bonding techniques
• Significant Prefabricated spares such as body tubes, nose cones ets

Yes, if there was a mass market for water rocketry we could buy factory-made bottles of any volume pre-formed in low-Cd aerodynamic shapes, with integral molded-in Haack nosecones. We could buy off-the-shelf dependable deployment/recovery modules that would neatly snap on to pressure vessels, with a table of values to refer to for setting the deployment time correctly depending on what modules we had selected.

Where would be the fun in that? ANd if you want to see beautiful home-made water rockets, go search for Batkiter.

4) High pressure motor build from "blue" tubes ( http://www.apogeerockets.com/blue_tubes.asp, http://www.rocketstore.co.uk/shop/prodt ... istory=cat )

For me this is probably the most interesting idea. These tubes can potentially revolutionise water rocketry. They can be a cheap alternative for reinforcing.

This is interesting. It seems to be a paper/card tube rolled tightly, as per traditional pyro rocket bodies, but the paper is impregnated with resin to strengthen it. I saw stuff about what pressure it could withstand, but I got the impression that that is instantaneous pressure not sustained pressure. Can it be made air/water tight, and can it hold pressure for long enough on the launch pad? One to watch.

5) Further development of the currently used deployment system.
• Smaller and lighter flight computer
• Different materials
• Smaller and lighter battery

I think you've got the right approach, get it working first then tart it up, make it lighter, stronger, better looking. I am impressed with your road-map approach to developing a water rocket - milestones give you something tangible to aim for, and something to celebrate when you achieve it.

6) Utilisation of RockSim in the rocket design process.
I see a lot of potential in the tool for Wrocketry.

Absolutely! See this article WARNING: links to a PDF http://www.apogeerockets.com/Education/ ... ter219.pdf[/quote]

Thank you for the comments Steve.

I'm not planing to start any business. It's all about, as you've said, building my personal rocket fleet. However, I disagree about your standardisation point. Firstly, using standard materials or parts does not make for example conventional rocketry less fun. Secondly, in fact building from pre-manufactured parts and materials very often is cheaper. For money I spent on paper and paint building a payload bay for our rocket I could have made two stronger and lighter from standard tubing spending a fraction of the time. For me the fun is in the designing and testing a new idea quickly and preferably cheaply, but not in the try-and-error process. The life is too short.

As for the Blue Tubes judging by the picture on Apogee site the things are quite strong. I would assume they can withstand a considerable pressure. The inside can be protected with several coats of paint for example.

[U.S. Water Rockets1]

There's nothing wrong with having pre-manufactured parts that people can buy and put together if that is what it takes to get them interested in water rockets. A simple and easy to make water rocket composed of modular sections with some of the more challenging aspects pre-engineered would go a long way to getting more people involved in the hobby of water rockets, and it would also help keep people safer when the get started out because of the reliability engineered into sections like recovery systems, etc.

Our view is that there's no way that a mass produced module system will outperform a purpose built system designed for a world record. The rule against pre-made parts is actually somewhat redundant, as there does not seem to be a lot of readily available parts for water rockets. The rule as it is written seems more like a way to prevent teams like us from getting rich selling flight computers and pressure vessels to other teams. It keeps the playing field level.

[rockets-in-brighton]

There's nothing wrong with having pre-manufactured parts that people can buy and put together if that is what it takes to get them interested in water rockets. A simple and easy to make water rocket composed of modular sections with some of the more challenging aspects pre-engineered would go a long way to getting more people involved in the hobby of water rockets, and it would also help keep people safer when the get started out because of the reliability engineered into sections like recovery systems, etc.

You can already buy off-the-shelf entry level water rocket launchers and basic water rockets, and that's great, it lowers the bar to entry. I agree that it would be nice to have multi-stagers or deployment systems also available for those who don't enjoy tinkering antigravity has some of course, not aware of any others - but I think you'd have to be making them in big numbers to drive the cost down. It seems to be more like a garden shed scale industry to me, which means high cost, low volume. If I thought there was a big enough market I think I'd go for it, starting with those ready-made 5 L aerodynamic pressure vessels But the R&D and tooling costs are probably way too high for an individual. There's also the issue of thousands of damn patents that have wrapped up and locked away most of the obvious and simple launcher and mechanical deployment designs.

In any case I think TheSkyDart was comparing the state of high power/advanced pyro rocketry with the equivalent state of the art in water rockets - I guess at the world record level of performance

Our view is that there's no way that a mass produced module system will outperform a purpose built system designed for a world record. The rule against pre-made parts is actually somewhat redundant, as there does not seem to be a lot of readily available parts for water rockets. The rule as it is written seems more like a way to prevent teams like us from getting rich selling flight computers and pressure vessels to other teams. It keeps the playing field level.

As far as I can see you're free to make and sell whatever you want, on the understanding that your work can't be used in someone else's WRA2 record claim.

I believe you've said in the past that you prefer a 'darwinian' approach to supporting other high-power water rocket efforts... let them build up the capability slowly by themselves until they are either competent, or they drop out before it gets too dangerous.

[rockets-in-brighton]

I'm not planing to start any business. It's all about, as you've said, building my personal rocket fleet. However, I disagree about your standardisation point. Firstly, using standard materials or parts does not make for example conventional rocketry less fun. Secondly, in fact building from pre-manufactured parts and materials very often is cheaper. For money I spent on paper and paint building a payload bay for our rocket I could have made two stronger and lighter from standard tubing spending a fraction of the time. For me the fun is in the designing and testing a new idea quickly and preferably cheaply, but not in the try-and-error process. The life is too short.

As for the Blue Tubes judging by the picture on Apogee site the things are quite strong. I would assume they can withstand a considerable pressure. The inside can be protected with several coats of paint for example.

Don't get me wrong, I have no problem with professionally manufactured components in this hobby. I just think that you'd need a mass market to support it (continental at least) with all the scaling problems that brings - advertising, shipping, point-of-sale and all that stuff. I would guess that pyro rocketry at all scales numbers participants in the tens if not hundreds of thousands in the US alone. I can walk into a local toy and game shop in the UK and buy a small ready to fly pyro over the counter, for not much more than the price of a couple of movies on DVD. To get that level of availability and cheapness you need similar numbers of buyers. Also pyro rockets have consumables to sell on top of the basic kits; basic water rockets just need water and air and muscle power (which is why they are compelling and accessible in the first place)

For the blue tubes, could you use it as a reinforcing sleeve over a PET bottle, to get around any issues of permeability?