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Those E size motors looked tempting to buy...just sitting there...waiting for somebody to buy them...waiting...

I was reading and do i need any certification to launch an E size rocket. I also read i need to have FAA clearance (how do i do this if its uncontrolled airspace?). If I need FAA clearance in uncontrolled airspace couldent i just say, launching a rocket over blah blah blah, in 5 mins...so move!? Or just not say anything at all?

Otherwise ill stick to the multistage rocket idea...and building the alien8 (atm im still working on my vacuum tube rocket. Trying to get it to go over the fense lol)

-Noah
 
Nope - none necessary for a single E motor. Any rocket <1lb, or with less than 113 grams of propellant (an E9 is 35.8g) requires nothing but a big enough field. Beyond that, in the >113g but less than 125g propellant, or with >1lb but <3.3lb liftoff weight, you have to notify the FAA. Beyond that, you need a waiver. Also, you need certification for anything H and above, as well as anything that has over 62.5 grams propellant in jus one motor (or more than 125 in the whole rocket). So an E9 is perfectly safe :)
 
If you are talking about the Estes E9, take care however... It has less raw *lifting* ability than the D12 and not much more than the C6...

It is not what I would call a "load lifter" :) The long burn time give lighter rockets a great ride though!
 
Hey, I'm 16 and I'm gonna get my Junior Level One certification soon. It'll allow me, even being under 18, to fly H and I motors. It looks like cjl is also under 18 and he already has his junior level one. It's a worthy goal once you think you've gained enough experience with the lower and mid powered stuff. Since you're just starting out I'd try some mid-powered kits from PML or LOC before going after the level one.

Did you recently have your birthday or something?
 
Originally posted by noahnott
Ummm, you guys keep forgetting: im only 16 (now im 16), not 18....

I think you need to be 18 to buy E engines.

Never mind... That's only in CA, NJ, and Canada.
 
Oh i was reading the back of the box and it said "must be 18 years or older to purchase in the US"...unless it really actually said "must be 18 years or older to purchase in CA and NJ."

And you noticed! Yeah, i turned 16 on June 3rd. =D (no liscense tho, dont want one)

-Noah
 
Right, back to one of my questions...

You know what i mean by the rockets that are asymetrical, what not, orbiter looking, thingamajigs? If not, cant explain it better.

Is there a website that I can read to explain to me how I find its stablility and where to put the motors? (I found one on apogeerockets.com about fins, but im saying actual body tubes and stuff).

Thanks,
Noah
 
sure....

www.nasa.gov ;) :p just messing with you ;) I don't know of a site but the shuttle is a great place to start

thanx, Ben
 
Yeah, i tried that website. They didnt give me the plans for the saturn V unfortunatly.
 
I disagree with the E9s lifting ability. Estes has them rated to lift more than D12s. They must know something. Or don't they know what they are talking about?

Looking at the Thrust curves in the Estes Catalog: the D12 has a higher peak thrust, and more area under the curve above 10 N than the E9, but the E9 hits 25 N earlier than the D12. By contrast the C6 only peaks at 15.3 N. The E9 also flattens out to 10 N just like the D12. The 9 is an avg thrust, and the longer burn time makes its avg thrust lower.
 
Really? I always figured the 9 and the 12 usually mean something =P But that isnt for lifting is it, thats the "total impulse" whatever that means. Um, whichever way, E9's are "awesomer". (no ive never tried one, biggest is a C11 which i found boring compared to a C6)
 
9 or 12 equals average thrust.

Total impulse is told by the letter.
 
Originally posted by MarkH
Looking at the Thrust curves in the Estes Catalog: the D12 has a higher peak thrust, and more area under the curve above 10 N than the E9, but the E9 hits 25 N earlier than the D12. By contrast the C6 only peaks at 15.3 N. The E9 also flattens out to 10 N just like the D12. The 9 is an avg thrust, and the longer burn time makes its avg thrust lower.
Now look at the NAR data:
https://www.nar.org/SandT/NARenglist.shtml
Their E9 didn't hit 25 N before the D12; in fact, it didn't hit 25 N at all, it didn't even quite make 20 N! By contrast, the D12 peaked pretty close to 30 N.

I'm a bit suspicious of Estes' engine table which not only gives an E9 a higher maximum lift weight than a D12 with a 1 second shorter delay, but also gives the same maximum lift weight for the B6-4 as for the C6-3. :)

What the E9 is really good for is clustering. Especially parallel staging. Put a couple of strap-on boosters with C6-0's onto a rocket with an E9 in the sustainer, for example.

As for the C11, it's effectively a short D12. The best use for a C11 is probably in a rocket which would normally take a D12, only you're in a small field and the rocket would get lost. So you use a C11 instead, which will give the rocket enough power to launch safely but won't take it as far. A rocket which needs a C11 may be too heavy to launch safely on a C6.
 
Interesting. Based on the Estes curve I wondered why Estes didn't rate it higher than E9 (like E10 or E11) when its thrust is only less than 10 N briefly at ignition and when it tails off at the end. With the NAR curve the E9 does seem pretty weak. Hmmm. Estes need to provide more accurate info in their catalog or have NAR recertify, otherwise their weight recommendations are misleading and perhaps a safety issue.
 
I flew my Big Daddy (it weighs about 12oz empty) on an E9, and it went up about 30 feet then horizontal.
 
I reinforced the fins with paper, built a kind of piston/baffle where the chute is stored in the nose cone, and did internal fillets. I don't remember the exact weight, but it was somewhere around 12oz.
 
A short flight up followed by a long flight horizontally often means the rocket is marginally stable. Where is the CG on your Big Daddy?

An average thrust of 9N on a 12oz rocket means a thrust/weight ratio of about 2.7. I don't like to fly with anything less than a thrust/weight ratio of at least 3, and I like slow, heavy rockets! Most people prefer a thrust/weight ratio of at least 5.

Your Big Daddy probably needs a longer launch rod and it certainly needs more power - like I said, the E9 is good for clustering! You probably can't remove the motor mount to replace it with one to hold two E9's. So this might be a good time for you to learn about parallel staging, alias strap-on boosters. :) A search of TRF for either of those terms should give you some information to work with. Add a couple of side booster with D12-0's and enough nose weight to make it stable with the added motors, then see what it does...
 
I think it was more likely weathercocking and being under-powered than marginal stability, but I don't really know. It flies really well on 24mm reloadable motors, especially E18s.
 
That's pretty conclusive. I doubt that an E9 is much heavier than a reloadable, so using an E9 shouldn't affect the rocket's stability. But an E18, by definition, has double the average thrust of an E9, therefore double the thrust/weight ratio, which puts it safely over 5.

A single E9 just doesn't move that heavy Big Daddy fast enough.
 
An E9 and an E18 both weigh 2oz. A single E9 should be enough for a stock Big Daddy, which should weigh 5.3oz (but will probably end up at more like 6oz)
 
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