Submitted by goatharper t3_zyp4vw in space
He's serious. These guys need FAA clearance to launch, and hit 30,000 feet. He mixes his own solid propellant, makes his own nozzles. it's a whole culture, and it was so cool to get a glimpse into that world.
I was able to ask some actual questions: "What's the total impulse on that motor?" so that I sounded like I knew what I was talking about..
Four thousand Newton-seconds. It was a tiny baby motor. Still very cool.
Woah... I never put that together... October Sky is just Rocket Boys scrambled...
Neat...
My world crumbles before me
Some other options which didn’t make the cut:
By Escort OK
Brooke Cyst
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I watched a video about one of these guys making their own rockets, very cool.
Unfortunately, most videos on YouTube along the lines "I built a rocket motor" are made by clueless people who got lucky not to hurt themselves, others, and not burn to the ground their or other people's property in the process. They should be only used as an example how to not make rocket motors. Not saying every single one, but vast majority of those.
They are becoming a scourge of the hobby. Similar how quadcopter idiots did serious harm to model airplanes hobby recently.
No, this person was legit, maybe it was the same guy, if he makes videos.
L class motor. Tripoli/NAR Cert level 2 flyers. What is the biggest motor they have flown?
Not sure, but he showed me the motor he had originally planned to test: about three feet long and four inches in diameter. As he had invited a few of us neighbors to watch, he fired the small one to give us a show.
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I went to an LDRS event once, it was pretty cool.
If you wanna sound like you know what you are talking about, use the word "thrust" instead of impulse.
Depends. Impulse and specific impulse are equally viable to talk about when comparing rocket motors.
Agree, specfic impulse and thrust are two differnt things.
Brilliant. I love when 'regular' folk do stuff like this. I just hope you are in the country and not in row houses..... I wish him tons of luck.
No, we are on 30 acre plots out here in the Texas hill country. He lives in San Antonio and has the place next door specifically so he can test his rocket motors.
We run goats on our place because there is a tax break that turns the property tax bill from thousands into hundreds. The goats actually came with the property. They are so much fun:
That looks amazing. And so different to the UK and NJ I'm used to. Good luck with the goats.
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How many times has your neighbor watched October Sky?
I wouldn't so much call it a motor as an engine. A motor implies rotation to impart energy to a process.
No it doesn't.
Motor implies it doesn't need air. Engine implies that it does.
So: Jet engine, rocket motor. Gasoline/diesel/steam engine, electric motor.
An engine is a specific type of motor but not all motors are engines. Engines are thermal devices -- they convert heat energy into motion. You could build a steam engine that doesn't require air but it would still be an engine because it uses the heat expansion of water to create a motive force.
>You could build a steam engine that doesn't require air but it would still be an engine because it uses the heat expansion of water to create a motive force.
We have them today. It's called a "nuclear power plant". No one I know calls it a "nuclear engine", or a "nuclear motor", for that matter. Even when they are used for propulsive power (like for submarines and aircraft carriers).
That's because the nuclear part only generates the heat, it doesn't provide the motive force. A steam turbine is the motor but we don't call a steam turbine an engine either even though we could. Nuclear power is used to generate electricity which in turn powers electric motors. That's why we don't call them nuclear motors or engines. We do have some nuclear detonation propulsion engines though but they have a whole host of other problems.
>Nuclear power is used to generate electricity which in turn powers electric motors.
Not always. Often, a PWR (pressurized water reactor) is used with a closed loop of superheated water that turns water into steam in a heat exchanger in order to directly drive propulsive turbines which are geared directly to the screws.
For example, the USS Tullibee was the first US submarine to use turbo-electric drive like you're thinking of, all of the other nuclear submarines before it used direct drive.
And almost all of the submarines afterwards. The Los Angeles class, for example, has the turbines connected physically to the screw, as does the current Virginia class subs (connected physically to the pumpjet).
In fact, I don't think the US has any nuclear powered ships that use turbo-electric propulsion. I know the Royal Navy does, though.
Very cool, I didn't know that. So do we call those steam engines or nuclear motors?
And the amazing thing is since we're just boiling water to create steam, there are so many better options besides nuclear.
There is no connection whatsoever between the two parts of that sentence. There are reasonable arguments against nuclear power, but “it just boils water” isn’t one of them.
Yes it is. Because alot of people incorrectly believe that there is something magical about nuclear power. It just boils water. That waste stays for a long time, in the thousands of years. They aren't able to deal with it now, and I don't see anyone being able to deal with it later. Hangout at a nuke plant sometime. Be amazed and horrified with how much the Simpsons got right.
I’m not at all surprised that you get all of your knowledge of nuclear power from the Simpsons. That explains why you think that nuclear plants boiling water is some kind of secret that no one knows about (on the Simpsons, the cooling towers emit some kind of noxious smoke).
But no, real nuke plants are not like that. Please don’t talk as if you’ve been to one.
It's not a well known secret, but enough people are surprised to find this out. And yeah, it's just not something that can be "greenwashed"
That depends on the application. For some applications, nuclear reactors are the best option.
In absolutely limited applications. Just making them to make power for residential consumption? It's a bad idea. The waste is out there, and it's real.
What is water made of
H2O
O-oxygen
Steam engines need air
Just because an element is part of a molecule doesn't make it a part of something else. Air is mostly nitrogen, not oxygen. You can't breathe pure water vapor, it's not air. Internal combustion engines cannot burn water vapor. If you can figure out how to burn water you'll be a billionaire and save the planet.
I can’t find a single definition of “motor” that supports this.
It's how it's used conversationally.
We don't talk about electric engines, for example.
We do sometimes talk about the motor in a car, though, so it's not perfect, just a general rule.
Most DIY rocket propellent tube thinginies are called Motors. Dunno why.
Apart from the fact that model rocket engines have always been called motors, most definitions of the word “motor” don’t involve rotation.
mrmaweeks t1_j27ih16 wrote
Sounds like the movie October Sky, which is just Rocket Boys—the name of Homer Hickam’s autobiography—spelled differently.