G'day I'm George from Australia, but first let me apologize that this post is in English, even though this is a German forum. Unfortunately my German now is almost non-existent, although I lived in Nürnberg for almost a year when I was around 10 years old.

Our team flies water rockets here in Sydney with the NSW Rocketry Association. We like both forms of rocketry (pyro and water), though currently we are enjoying the water rocket engineering challenges.

I have been a big fan of raketenmodellbau.de over the last several years, and I'm very impressed with the amount of information and technology presented here. I use online translation tools to convert the posts to English, which hasn't been too bad.

We would like to keep in contact, and help contribute to the forum where we can, and always happy to answer any questions.

Cheers

- George

Air Command Water Rockets

I've included an automated translation of the above (hopefully it makes sense )


Ich habe auch eine automatisierte Übersetzung der oben (hoffentlich ist es sinnvoll )

G'day Ich bin George aus Australien, aber laß mich zuerst entschuldigen, dass diese Stelle in englischer Sprache, obwohl es sich um einen deutschen Forum. Leider ist mein Deutsch ist nun fast nicht existent, auch wenn ich in Nürnberg für fast ein Jahr, als ich etwa 10 Jahre alt.

Unser Team fliegt Wasser Raketen hier in Sydney mit dem NSW Rocketry Association. Wir mögen beide Formen der Raketentechnik (pyro und Wasser), aber derzeit sind wir genießen das Wasser-Rakete Engineering Herausforderungen.

Ich war ein großer Fan von raketenmodellbau.de in den letzten Jahren, und ich bin sehr beeindruckt von der Menge an Informationen und Technologie vorgestellt. Ich benutze Online-Übersetzungs-Tools, um die Beiträge auf Englisch, die noch nicht so schlecht.

Wir möchten in Kontakt bleiben, und dazu beitragen, das Forum, wo wir können, und immer gerne für die Beantwortung Ihrer Fragen.

Cheers

- George
Air Command Water Rockets

Geändert von Tom am 12. Januar 2009 um 17:36

Hi George!

It´s great that you found the way to our forum. Welcome!
I think your english posting is no problem for the most of us.

Many of the water rocketeers in this forum are also visitors on your site. Especially these
flights with foam and boosters are fascinating. You have already posted a lot of videos at
YouTube.
At the moment, some of us are trying to copy that.

I´ve got some special questions:
In Australia and US you use this PL Premium. What kind of glue does it is? Does it contain
polyurethane? I expect it´s the same like the german UHU PU-Max.

When launching your booster rocket, how high is the acceleration of the center stage after
booster separation? Do you use small nozzles for lower acceleration?

Do you have only these no deposit bottles in australia?

Greetings to down under

Robert

Hallo George,
welcome here, I also think that english is not the problem, babelfish will help
Greetings
Andreas

Hello George,
welcome to our forum, i also think that english is a smaller problem. Your water rocket projects are very interesting for me, especially the "foam rocket" and i´m very intersted in the way it works.
I´m looking forward that this is the beginning of a great relation between the nations

greets
Dennis

Hello George!

It's fantastic to have a great water rocketeer like you in our forum!
Some of your invented techniques had been noticed with a big interest, like Robert already told.
The underwater starts had been cool too, that's something which isn't easy to try here.

Your inventions are great and the way you are documenting your tests and flights is very accurate - nearly like scientific research.

Regards to the other side of the world!
Markus

--------------------------------------------------------------------------------

Hallo George!

Es ist fantastisch, einen großen Wasserraketeur wie Dich in unserem Forum zu haben!
Einige der von euch entwickelten Techniken wurden mit großem Interesse wahrgenommen, wie Robert bereits gesagt hat.
Die Unterwasserstarts waren auch cool, das ist etwas was man hier nicht leicht ausprobieren kann.

Eure Entwicklungen sind großartig und die Art wie ihr eure Tests und Flüge dokumentiert ist sehr genau - fast wie wissenschaftliche Forschungsarbeit.

Grüße auf an die andere Seite der Welt!
Markus

Hello George,

its great that you are member of this forum now! I always was very impressed by your detailed website and great rockets!! As you can see, English is just a minor issue here. Everybody answers in English.

Best regards,

Hendrik

Thank you for the warm welcome ,

Also thank you to Tom for putting the post in the correct place.

Zitat:

---

I´ve got some special questions:
In Australia and US you use this PL Premium. What kind of glue does it is? Does it contain
polyurethane? I expect it´s the same like the german UHU PU-Max.

---

Yes the PL premium glue is polyurethane based, and it is very good at bonding to PET. It has very good consistency when applying it to the sections to be glued. It is not too runny like some other polyurethane glues.

The main drawback is that it bubbles a lot while curing and as a result it is a little porous. It isn't good for making nice smooth fillets for fins.

We can't buy it here in Australia and so it has to be imported from the US by water rocketeers.

I have noticed that many of the German water rockets use a white looking glue, I am guessing it is the
UHU PU-Max you are referring to. What is the consistency like? Is this glue widely available in Europe or is it specifically within Germany? People from Europe often ask us for alternatives to PL, but I never know what to recommend.

Zitat:

---

When launching your booster rocket, how high is the acceleration of the center stage after
booster separation?

---

The acceleration of the main stage is quite low at separation perhaps around 1-2G. We extend the "burn time" on the main stage for a number of reasons:

1. The lower rocket velocity reduces drag if it can fly slower for longer, rather than faster for shorter.
2. There is enough time for the main stage to properly separate from the boosters. If it burned out around the same time they may not separate cleanly.
3. Less stress is put on all the components at the lower acceleration.
4. A long foam trail makes for good photos and video

Although this may not be an optimal solution for maximum altitude, for us maximum altitude really does not matter since we are not trying to break any records, we are just having fun building and flying rockets. We are happy if the rockets fly high, but we prefer to focus on the engineering and science experiments.

Zitat:

---

Do you use small nozzles for lower acceleration?

---

Yes we do. We also use the foam to extend the burn time and reduce acceleration. But this has the problem of making the rocket more unstable as much of the weight is near the tail of the rocket for a lot longer. A lot of our foam rockets tend to be unpredictable where they fly. We will need to put fins a lot further back to make the rocket stable with water still in it.

Zitat:

---

Do you have only these no deposit bottles in australia?

---

Yes, unfortunately the bottles are pretty thin walled and do not hold a lot of pressure. I am hoping to get away from bottles altogether for the bigger rockets and make up thin walled fiberglass pressure chambers eventually. I was amazed to see how light and strong the pyro rocket guys make them for their rockets.

What kinds of bottles are available in Germany? I have seen people using 3L bottles, are these common? We don't have anything like that here.

Cheers

- George

Hi George,

nice to have people here from down under. When I was there I thought that the outback would be a nice place to launch some giant rockets. Do you have any information about the regulations of launching rockets in australia?

Zitat:

---

What kinds of bottles are available in Germany? I have seen people using 3L bottles, are these common? We don't have anything like that here.

---

We have different sizes. The normal size of reusable bootles are 1l and 1,5l. The reusable bottles have a thicker wall and can handle higher pressure. Than we have 2l and sometimes 3l bottles. This bottles are for single use and have thinner walls. So not so good for building rockets. If you drink from a 3l bottle the end of the drink has nearly no CO2 anymore. That is not nice and I think also the reason why it is not so comon.
Robert discovered some round bottles with 30l. They are used as beer barrels.

Greetings

Neil

Hi George!

Zitat:

---

I have noticed that many of the German water rockets use a white looking glue, I am guessing it is the UHU PU-Max you are referring to. What is the consistency like?

---

No, that is the PU-Leim from Henkel. There are several distributors of polyurethane glue in germany
for example Henkel, UHU, Simson, Fermacell and some others.
The consistency and colour of UHU PU-Max is like honey, i would say.

I don´t konw if these glues are also avaiable in other european countries.

You got no glue in Australia so that you have to import it? Jesus!

Zitat:

---

A long foam trail makes for good photos and video

---

That is realy true. I like these flights of the Polaron IV rocket

Do you know the KeyKeg beer barrels?
Look at this:


We´re trying to build rockets with these barrels at the moment.

Greetings

Robert

Hey George

Welcome here at these water rocket forum
i've surfed @ your fantastic water rocket website
you are a very great water rocket buider

Mfg Alexander