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Questionable Off-Topic Post Request
Posted: Sat Oct 01, 2011 7:37 pm
by danielrowell
To the moderators: I was wondering if I could start a thread on model rocketry in the Off-topic section.
Many of the members know so much about physics that I thought it might be neat to start a thread on model rocketry. (by the way, I mean rockets more like
these, not necessarily the tiny Estes rockets.)
Though model rockets contain solid propellants, the propellants themselves are created by manufacturers and their materials aren't generally disclosed, nor are they commonly modified. Or, would model rockets come to close to qualifying as incendiary projectiles?
Posted: Sat Oct 01, 2011 7:46 pm
by Gun Freak
Usually people just start the thread and see if the mods like it haha. If they don't approve they'll just lock it. I think if you keep the discussion away from the propellant then it'll be okay...
Posted: Sat Oct 01, 2011 8:07 pm
by MrCrowley
It may be allowed but due to the possibility the model rockets get mixed up with spudguns (the media would be happy to oblige), I will forward this thread to PCGUY (the Admin) for the final word.
Posted: Sat Oct 01, 2011 8:09 pm
by danielrowell
Thanks MrCrowley! That was my primary concern.
Posted: Sun Oct 02, 2011 2:34 pm
by jrrdw
One main problem with the class rockets you linked to is the motor size. Typically the largest size/power motor you can get over the counter (legal) in the USA is a 'D' size. The class you linked to take 'G' witch is the next size up/twice the power.
I wouldn't mind launching one that would reach 3,000 feet.
Posted: Sun Oct 02, 2011 5:46 pm
by danielrowell
Apogee Components makes F power motors that they can ship legally via USPS to avoid the hazmat charges. It stinks that they can't ship outside the US, though.
I wouldn't mind launching one that would reach 3,000 feet.
With one of Apogee's long burn F motors, I designed one one in a simulator that is projected at 7,900 feet...
[Edit] In terms of AeroTech's Loadable Motor Systems, motors all the way up to the G size can be shipped without a hazmat fee. (see
this) It's legal, and no certification is required.
Posted: Sun Oct 02, 2011 8:13 pm
by saefroch
And of greater import... would this thread allow discussion of homemade rocket fuels?
Posted: Mon Oct 03, 2011 6:07 am
by jrrdw
AEROTECH wrote:"AEROTECH SINGLE USE D, E, F, G ROCKET MOTORS
Click on rocket engine description to get thrust curves, dimensions, propellant type, certification info, etc. The following model rocket engines have to be shipped by snail mail ground. Please allow 1-2 weeks for delivery by mail or
2 -5 days with a Hazmat fee. Rocket engines, igniters or model rocket starter sets containing model rocket engines or igniters can not be shipped outside the USA. All other items on your order will ship in the same box unless you place two seperate orders
AEROTECH SINGLE USE F, G ROCKET MOTORS
The following model rocket engines must be shipped with a $25.00 Hazmat fee. They can not be shipped by mail!
This fee is required by the shipping company.
You MUST pay 1 hazmat charge for the motors to ship, regardless of how many motors are ordered. That's 1 hazmat charge per order, not per motor.
The Hazmat charge is not automaticly added, you must add 1 to your order or it will NOT ship.
Rocket engines, igniters or model rocket starter sets containing model rocket engines or igniters can not be shipped outside the USA. All other items on your order will ship in the same box, if possible, unless you place two seperate orders.
Click on rocket engine description to get thrust curves, dimensions, propellant type, certification info, etc."
Wow this has to be read carefully to understand it but it does explain itself.
1 thing I want to point out in my earlier post about buying rocket motors. You can't get them over the counter (larger then 'D') that I know of, it's been a long time since I been in a hobby shop. The laws on this have or might have changed, I'd like to find out...
@saefroch, that's a good question. What exactly and how exactly are you referring to? PCGUY has not posted yet so get the info up front here so he sees it and can make a decision on it.
Posted: Mon Oct 03, 2011 7:53 am
by danielrowell
saefroch wrote:would this thread allow discussion of homemade rocket fuels?
Here's what I found on the Aerotech site.
Experimental Rocketry
Those who build their own rocket motors rather than using commercially manufactured motors engage in a hobby rocket category known as
"Experimental Rocketry". Motors can be any size, though generally they tend
to be in the larger high-power range. In some ways, experimental rocketry
is less regulated than high-power rocketry, although the FAA requirements
are the same. Making your own motors can be dangerous and should not be
undertaken lightly. Experimental rocketry is appealing to people who either
want to do everything themselves or enjoy the process of developing and
making their own motors. It should be noted, however, that making your own
motors is rarely a money-saving proposition.
Based on that, I don't think it would be a good idea to make your own rocket fuel unless you have a very good idea of what you're doing. However, there are some people out there who have made relatively simple rockets that have worked well, such as
this. It should be noted that the man who made it works in the propulsion industry.
Posted: Mon Oct 03, 2011 10:50 am
by jrrdw
Packing your own rocket motors normally goes wrong when the proper tools aren't used. Anti-static stands, ceramic nozzle molds, body grounding cables etc...
When I first looked into building my own motors the 1st thing I learned was about people (mostly young teenagers) blowing themselves up, destroying their homes, garages and worse of all maiming themselves badly and having to live the rest of their lives like that, never being the same.
You have to build these tools and they have to be built properly. I suspect the lack of funding causing the bad decisions of taking short cuts in the building of the necessary equipment to build these motors properly. Lack of funding is what kept me from building my own motors.
There are re-loadable aluminum casings (kits) and re-fills available at Tower Hobbies that I have seen but the reviews are mixed.
Posted: Mon Oct 03, 2011 1:59 pm
by saefroch
Well... since my post has sparked such interest, I will attempt to respond to what has been posted in regards to it, but if I miss something, tell me.
I like how this:
jrrdw wrote:What exactly and how exactly are you referring to? PCGUY has not posted yet so get the info up front here so he sees it and can make a decision on it.
Suddenly became this:
jrrdw wrote:Packing your own rocket motors
Let's not start assuming already
What I was referring to is things along the lines of the sugar and KNO<sub>3</sub> solid rocket fuels, which often also include iron or copper oxide. I said nothing about the conventional black powder-like fuels that are often used in model rocket engines. My basic experimentation has shown this fuel to be far, far more stable, and not nearly as dangerous as the black powder-like conventional fuels. Sugar-based rocket fuels are not packed.
Posted: Mon Oct 03, 2011 2:16 pm
by jrrdw
There was way more to my post then what you quoted but members can see that for themselves. What I found during my studies on home made motors wasn't BP. It was different.
saefroch wrote:What I was referring to is things along the lines of the sugar and KNO3 solid rocket fuels, which often also include iron or copper oxide.
Rule 3, definition C will probably trump what I quoted above. In fact don't be surprised if rule 3 in it's entirety doesn't trump this entire discussion.
Posted: Thu Oct 06, 2011 8:23 pm
by PCGUY
I don't mind people posting about using premade rockets, as long as they are in NO WAY used or linked with spud cannons in ANY way. As far as modifying premade rocket engines, or making your own, sorry that falls too much into the pyrotechnics category which opens up a whole new set of laws, laws which have no place being mixed with spud cannons.
Thanks for asking guys I really appreciate it
Posted: Fri Oct 07, 2011 8:54 pm
by danielrowell
Thanks PCGUY!
I'll start the thread soon...
Posted: Sat Oct 08, 2011 1:24 pm
by jrrdw
danielrowell wrote:Thanks PCGUY!
I'll start the thread soon...
http://www.spudfiles.com/forums/model-r ... 23428.html
So there isn't 2 thrteads about the same topic.