Model Rockets

[sharpiel]

I loved building and launching model rockets as a younger and later a middle aged man.

Got right into the science of it with (impractical) dreams of building a remote control multiple stage rocket. Those never eventuates of course...imagine trying to RC something that fast. Anyway...

Who else has interests in model rocketry? Any pics to share?

I particularly like the simple and elegant shape of the V2. That'll be my next project I think.

[clive milne]

Yep... but I used to roll my own motors so to speak.

Experimented with (home made) black powder as well as sugar and potassium nitrate - which was interesting in that you could basically make a kind of toffee to pour in to the casing... and of course, zinc dust and sulphur - the rockets containing that stuff used to leave the ground at a rate completely in defiance of any rational interpretation of laws of physics. Perceptually, it was like seeing a pillar of smoke suddenly appear in the sky, with a shiny metal object leaving your peripheral vision never to be seen again.
Watch this to get an idea:
https://www.youtube.com/watch?v=JT4RoRg9TCk

Also machined up a liquid fuelled rocket motor when I was an apprentice... never did fire it up though. There was the small mater of acquiring an oxidant. Not the sort of thing you can justify as an over the counter purchase when you are a teenager.

It's sad that in today's political climate you can no longer play with that sort of stuff without ASIO knocking on your door.

Probably just as well...
it's a miracle that I still have all my fingers and eyesight still intact considering the risky stuff I used to entertain myself with as a kid.

[glend (Glen)]

My mates and I used to fire off Estes rockets on the vacant blocks in our subdivision (in Canada) when I was a kid. It was early days for model rocketry (back in the early 1960s), and we did some stupid things as young guys do with model rocket engines. It used to be so easy to buy them too, we could order them through the mail from Popular Science. We did launch a few two stage rockets with parachute recovery, and that was neat because the whole NASA program was just getting under way at the time to inspire us. Sadly the two stage rockets were much easier to lose, ha ha. It is nice to see that Estes is still in business today, after starting up in 1958..

[sharpiel]

Originally Posted by clive milne

Yep... but I used to roll my own motors so to speak.

Experimented with (home made) black powder as well as sugar and potassium nitrate - which was interesting in that you could basically make a kind of toffee to pour in to the casing... and of course, zinc dust and sulphur - the rockets containing that stuff used to leave the ground at a rate completely in defiance of any rational interpretation of laws of physics. Perceptually, it was like seeing a pillar of smoke suddenly appear in the sky, with a shiny metal object leaving your peripheral vision never to be seen again.
Watch this to get an idea:
https://www.youtube.com/watch?v=JT4RoRg9TCk

Also machined up a liquid fuelled rocket motor when I was an apprentice... never did fire it up though. There was the small mater of acquiring an oxidant. Not the sort of thing you can justify as an over the counter purchase when you are a teenager.

It's sad that in today's political climate you can no longer play with that sort of stuff without ASIO knocking on your door.

Probably just as well...
it's a miracle that I still have all my fingers and eyesight still intact considering the risky stuff I used to entertain myself with as a kid.

Clive that's all pretty impressive. The liquid fuelled motor most of all. Do you still have it anywhere?

In terms of RC a "rocket"...these days you can buy small operating liquid fuelled jet engines. Though not truly a rocket powered rocket, concealing one of these inside a rocket shaped body could be fun. More a guided missile than a rocket perhaps.

[Nath2099]

Originally Posted by sharpiel

imagine trying to RC something that fast

https://www.youtube.com/watch?v=sa-TSNeTK-A

Prob not as fast as a rocket, but pretty bloody fast none-the-less!

[cfranks (Charles)]

Fairly old video from a bunch of Thai amateurs.

http://theawesomer.com/insane-homebrew-rocket/303503/

[The_bluester (Paul)]

We have a little Estes model I put together for my (Then) 5 year old. We live on 44 acres so have a bit of freedom to toss things like that at the sky.

That youtube footage of the zinc and sulphur rocket is insane!

[sharptrack2 (Kevin)]

I just tossed all of my rocketry items a couple of months ago. Some kits, broken models, Launch apparatus, etc, was all boxed up with the best intentions of getting back into it. The box came with me when I moved here 14 years ago, but with Australia being so strict about safety and all, and bush fire risk, and other hobbies taking up most of my time (staring at bright spots in the sky being one of them )I have finally given up.

My favorite was the Estes photo taking rocket. Instamatic type camera mounted in the nose cone. The nose cone exiting the body was the trigger for the camera. For all the marketing hype it never did work quite right. I eventually designed my own with a delay to allow the nose cone to stabilise a little after chute deployment.

[The_bluester (Paul)]

Regards the fire risk, I only ever launch mine in the wetter months for that reason.

[clive milne]

Originally Posted by sharpiel

Clive that's all pretty impressive. The liquid fuelled motor most of all. Do you still have it anywhere?

Not anymore... that was like 30 odd years ago.

fwiw) The combustion chamber was machined to include a labyrinth of cooling channels. The idea was to run the fuel up and around the combustion chamber (counter-flow) before entering the top of the engine in an attempt to keep it cooler.

I pressured it up a couple of times with water and compressed air which made for a pretty impressive spectacle even without flame. Looking back on it if I am to be honest with myself, I guess part of the reason I didn't pursue it further was a sense of self preservation. You look at the quantity and energy of the stuff exiting the business end, then make the intuitive guess of what that would look like as a product of combustion... Some tiger tails are best left un-tugged.

At the time, I was also into building steam engines, so that was my main focus anyway.

[alocky (Andrew lockwood)]

Hi Clive, remind me to give you a copy of a book called 'ignition' next time we catch up. It is a first hand account of the post WW2 rocket fuel research, and is written in the most wonderfully dry but very funny tone by one of the main players in the field.
Considering the oxidants used range from liquid oxygen, fuming nitric acid and possibly the most terrifying substance known to man - FOOF, as dioxygen diflouride is 'affectionately' known, you should be commended for not getting any further...
The main problem seems to be getting reliable, continuous ignition, when you want it.
Cheers.
Andrew.

Originally Posted by clive milne

Yep... but I used to roll my own motors so to speak.

Experimented with (home made) black powder as well as sugar and potassium nitrate - which was interesting in that you could basically make a kind of toffee to pour in to the casing... and of course, zinc dust and sulphur - the rockets containing that stuff used to leave the ground at a rate completely in defiance of any rational interpretation of laws of physics. Perceptually, it was like seeing a pillar of smoke suddenly appear in the sky, with a shiny metal object leaving your peripheral vision never to be seen again.
Watch this to get an idea:
https://www.youtube.com/watch?v=JT4RoRg9TCk

Also machined up a liquid fuelled rocket motor when I was an apprentice... never did fire it up though. There was the small mater of acquiring an oxidant. Not the sort of thing you can justify as an over the counter purchase when you are a teenager.

It's sad that in today's political climate you can no longer play with that sort of stuff without ASIO knocking on your door.

Probably just as well...
it's a miracle that I still have all my fingers and eyesight still intact considering the risky stuff I used to entertain myself with as a kid.

[ZeroID (Brent)]

Got into it many years ago with Estes Moptors I imported as a youngster, Customs not so hyper critical then. Resurrected it a few years ago with sugar motors and was testing and build test rigs when I had few minor explosions in the back yard while under test. Now I've got a large bag of KNO3 fertiliser down in the garage that is slowly being repurposed as it was intended, fertiliser, and I went into Astronomy.

Had some reasonably successful builds back in Secondary School days using Suphur\Zinc in 6' steel tube builds. School supplies could get you anything if you asked nicely. Gave that away after we had a serious 'Krushnik' event with one which took out the launch rail system. Google Krushnik and you will get the idea..

Astronomy is much quieter and less nerve wracking for sure...

P.S. Forgot about my years running a Fireworks Display Company. I could burn $20,000 of pyro in 6 minutes and people would think it had lasted 30 mins, The magic of high intensity events on the human mind. Lots of stories on that period, about 10 years of them.

[julianh72 (Julian)]

Originally Posted by clive milne

At the time, I was also into building steam engines, so that was my main focus anyway.

Home-brew Rocketry and Steam Engines: I guess that makes you the original archetypal Steam Punk!

[clive milne]

Originally Posted by alocky

Hi Clive, remind me to give you a copy of a book called 'ignition' next time we catch up. It is a first hand account of the post WW2 rocket fuel research, and is written in the most wonderfully dry but very funny tone by one of the main players in the field.
Considering the oxidants used range from liquid oxygen, fuming nitric acid and possibly the most terrifying substance known to man - FOOF, as dioxygen diflouride is 'affectionately' known, you should be commended for not getting any further...
The main problem seems to be getting reliable, continuous ignition, when you want it.
Cheers.
Andrew.

Hi Andrew... are you talking about the book by John D Clarke?

You seriously have a copy?

That is a rare and valuable collectors item!

For those curious, go here:
http://library.sciencemadness.org/li...s/ignition.pdf

As for dioxygen diflouride... it is probably just as well that I never pursued a career in academia.. That is the sort of madness that I would have been well into and first in the queue to have a play with.
It says something of the precursor when one of the (ostensibly) stable products of reaction is HF! (One could call it Satan's tears but for one significant difference - should you come in to contact with Satan, you can at least negotiate)

On somewhat of a tangent, I have a book which you also might be interested in on the subject of ballotechnics and their application as a thermonuclear trigger (without the need for a fission component)... you can see how that might be a white paper that will never reach the light of day?
Sam Cohen is supposed to be on record basically confirming it as genuine, and there have been enough scientists and weapons dealers found dismembered / in car boots, etc) in the public record to lend smoke to the fire, so to speak. Sobering stuff, and a whole new level of chemical insanity.

[clive milne]

Originally Posted by julianh72

Home-brew Rocketry and Steam Engines: I guess that makes you the original archetypal Steam Punk!

I think at the root of it, I was just fascinated in how an understanding of physical principles offered the opportunity to influence your experience of life. It was a bit like the allure of discovering that your Mechano set could be expanded waaaaay beyond the contents of the box... if you were prepared to learn how to make some of the 'not for sale' bits yourself.

I was the teenage nerd who read texts on quantum physics (not because it was cool, as it is in this contemporary "new age, dolphin polishers" paradigm... and stuff) but because I found it astounding and far more interesting than the 2 dimensional, mundane world that most people preoccupy themselves with. I fully acknowledge that it doesn't mean I am particularly intelligent... just curious.

[alocky (Andrew lockwood)]

Hi Clive - that's the one. Unfortunately I only have a PDF of it.

Originally Posted by clive milne

Hi Andrew... are you talking about the book by John D Clarke?

You seriously have a copy?

That is a rare and valuable collectors item!

For those curious, go here:
http://library.sciencemadness.org/li...s/ignition.pdf

As for dioxygen diflouride... it is probably just as well that I never pursued a career in academia.. That is the sort of madness that I would have been well into and first in the queue to have a play with.
It says something of the precursor when one of the (ostensibly) stable products of reaction is HF! (One could call it Satan's tears but for one significant difference - should you come in to contact with Satan, you can at least negotiate)

On somewhat of a tangent, I have a book which you also might be interested in on the subject of ballotechnics and their application as a thermonuclear trigger (without the need for a fission component)... you can see how that might be a white paper that will never reach the light of day?
Sam Cohen is supposed to be on record basically confirming it as genuine, and there have been enough scientists and weapons dealers found dismembered / in car boots, etc) in the public record to lend smoke to the fire, so to speak. Sobering stuff, and a whole new level of chemical insanity.

[xelasnave]

I had to give up early.
I used sulpher and zinc dust but the thing fell over and when into bush along the fence and started a huge fire. My parents found out and I had to stop with rockets.
I made a huge batch of fuel put it in a heap and set it off..all gone.
Interestingly the residue when water is added gives off rotten egg gas which was also fun until I was told not to do that either.
I have thought to get a rocket with a camera but decided I will just use google Earth.
Alex

[Boozlefoot]

In reply to Alex's rockets falling over. Drill and tap the bottom casing of the engine, add 8mm bolt. Problem solved, no more fall overs!

[sharpiel]

Originally Posted by Boozlefoot

In reply to Alex's rockets falling over. Drill and tap the bottom casing of the engine, add 8mm bolt. Problem solved, no more fall overs!

Hey Rod. What does the bolt do? Is that to change the center of mass or to hold the rocket to a test bench?

[ZeroID (Brent)]

Originally Posted by clive milne

... and of course, zinc dust and sulphur - the rockets containing that stuff used to leave the ground at a rate completely in defiance of any rational interpretation of laws of physics. Perceptually, it was like seeing a pillar of smoke suddenly appear in the sky, with a shiny metal object leaving your peripheral vision never to be seen again.
Watch this to get an idea:
https://www.youtube.com/watch?v=JT4RoRg9TCk

Burn rate on that stuff is 2m\sec, basically a long explosion in a tube. Any cavities or packdowns in the fuel load and you have a 'krushnik' explosion.