Hey all, I just found this site, and it's great. My name is James Mulroy and I live in Hortonville, Wisconsin.

I have some questions.

First of all I have just started a club, not many members, just some relatives, neighbors and friends. We are mostly interested in completely designing and building the rocket, the motor and all. At first I was going to use a black powder and alcohol mixture, then I remember rocket candy, from the rocket boys book. We will be using potassium nitrate and sugar as our propellant. However after september 11th, the ATF added KNO3 to their list of low explosives, on the NAR site I found this so I can obtain a permit : http://www.atf.treas.gov/forms/pdfs/f540013.pdf

and instructions here: http://nar.org/cabinet/leuphints.html

Now I am only 16 years old, and that permit apparently is for people under 18 years of age. However I'm not sure about if I can store these explosives or not. If anyone knows, that'd be great. Also, is there is a permit we can get that would cover the untire rocket group?

I also need to know about storage devices, you need a type 4 magazine for low explosives, but they are expensive, can I build one? Also, how do I properly transport the explosives?

I have contacted numorous organizations, from the ATF, AMA, ATC, BATF, the FAA, and the local fire department. They have all been sending me in circles, they have had me contact one organization, and then that organization has me contact another becuase they don't know the answer, and then I end up where I started; no where. This is getting very confusing as to which permits I need to launch a high powered rocket that is larger then said on the FAR 101 document. Any help to lead me in the correct direction would be great. What organizations are for what, that sort of thing.

As to the rocket itself, I have a ton of information about how I will build it. My uncle just bought a metal lathe, and since the temperature of the fuel is going to be so high, we decided to contruct the engine out of aluminum, however, for the rest of the rocket, we will follow the NAR guide line using only light light materials.

However, that seems kind of heavy and we may need a waiver for a rocket containing metal. Any suggestions for a better material that can support rocket candy? It has to be workable, like metal, a solid chunk of this material, so that we can spin it on the lathe.

For aluminum, I have been having problems, I need to know how strong it is, so I decide on a wall strength for the engine, a chart of some form perhaps would be helpful.

Also, I havn't found much on fin or wing design, as of formulas. And on the side of a rocket, if it is straight, there is some air resistence, but very little, does anyone know how to calculate, that amount. And what if the rocket sides slope back at an angle behind the nose cone. Then how do you calculate for it?

Also, what about alcohol and other liquid fuels, how does that change the rocket. The AFP sent me an application for distilling alcohol via email, I have not downloaded it yet, but I will. When I get the permit, I'd like to make some rockets that use pure ethanol. Obviously the storage compartment for the alcohol changes, but what about the rest of the rocket, does the nozzle change too?

I have been researching these things for a long time. At the beginning of this last school year, I got really interested in rocketry. I took physics this year and I am taking AP next year, however, the teacher doesn't always have an answer.

I am also a senior now, seeing as school just ended.

If you are interested, I will keep you all updated on our little club, the rockets. I'll post some pictures.

Also, my email is as follows; doggywoggydo@sbcglobal.net
If anyone ever needs to or would like to contact me then pleace email me.

Thank you for taking your time to read over this.

Welcome Aeronautical,

I'm not too sure if you'll find a lot of the type of info you're looking for here. Most of us launch with commercially available pre-loaded single use engines or reloadable engines that consist of a reusable casing and commercially made engine reload kits. If you are just starting an interest in rocketry, let me be the first to suggest that you start this way also. There are many inexpensive kits and pre-built ready-to-fly rockets available that are designs of proven stability. Check the vendors section here for a sample of the manufacturers and distributors. From your posting it is obvious that you are a young man with a good measure of intelligence. Please, for your safety and that of others - temper it with good common sense also.

__________________
John Lance Ladd
Yoyodyne Propulsion Systems
Grovers Mill, NJ
Established 1938
lladd.netau.net

I even tried reading this through Babel Fish and it made no sense.

__________________
Bill Eichelberger
NAR 79563

http://wallyum.blogspot.com/

I miss being SAM 0058

Build floor: Estes - Low Boom SST Semroc - Marauder, Shrike, SST Shuttle

In paint: Canaroc - Starfighter Scorpion Centuri - Mini Dactyl Estes - F-22 Air Superiority Fighter, Multi-Roc, Solar Sailer II, Xarconian Cruiser Semroc - Cyber III

Ready to fly: Estes - Solar Sailer II Semroc - Earmark

Rocketry Online used to have a forum subsection just for Experimental Rocketry. Not sure if it does anymore. I haven't been over there in several years. I've built and flown my own motors, but I learned from an experienced EX guy. It's better that you spend considerable time learning about it before attempting to build anything.

Cooking your candy propellant can be dangerous. My EX buddy almost burned his house down when he was about your age, just cooking up a small amount. Zinc-Sulfur motors and BP motors are probably the two most dangerous to make, specifically when tamping/compressing the propellant into the casing.

To be honest, Ammonium Perchlorate based motors are probably the safest to make, but it takes attention to detail and there are several components. HTPB is the easiest binder to work with. I used isocyanate for my catalyst, which is toxic to living tissue, but I believe there are other catalysts available. If you make motors of any size, regardless of AP based or candy propellant, you will need to know about grain geometry, nozzles, etc. to control chamber pressure. Please spend some time with an experienced person before setting out on your own. Even if it's just an online relationship, the time spent will not only make your efforts more safe, but it will save you a lot of money and time because you won't have to go through as much trial and error.

Good Luck!

I've been doing model rocketry for years, however I have never used any of the reusable motors. I will have to check those out. Is anyone here certified for level 1, 2, or 3 engines through Tripoli or the NAR, I'm just curious?

The 'zincoshine" or zinc-sulfer motors was what I was originally going to use, but the zinc in large amounts get's expensive I believe. Then I thought about black powder, however, that isn't as effective as the rocket candy, from what I have read. Mychemistry teacher I made some zincoshine once, it burns nice. And if you add ethanol, it's safer, it burns better, same with black powder. I know there are dangers when making your own fuel and engines, and that's why I am taking so many precautions, calling all these agencies up. I'll make sure to have all the permits I need first, and to have proper equipment, although expensive.

What I am most interested in though is not the propellant, but the nozzles and physics behind the rocket. Do those reloadables have some kind of nozzle?

Also, what I mentioned above were somethings I just havn't found much information on, the physics is the same for the experimental rocket as it is for rockets using estes or other store bought engines. So I thought I'd try this site. It seems like many of you do know what you're talking about, and I think I'll visit this site more often.

Any other information would be great and I will check into that rocketry online thing.

Thank You!

Yes, they have nozzles. The casings I use are made of aluminum and have graphite nozzles sealed by O-rings. They are held inside the casing with snap rings. You will need to understand terms like ISP, KN, etc. The nozzle diameter will be critical in order to get good performance without over pressuring the motor casing. At low altitudes, the shape of the exit cone isn't super important, but it will help a little to have the correct angle.

I stopped flying high power rockets, and therefore stopped doing EX motors after 9-11. My rockets, hardware and components are now just expensive dust gatherers. The BATFE went nuts over regulating the hobby and the cost of AP jumped after the Pepcon fire. It was already very expensive for me to fly HPR because I had to travel and stay in hotels due to needing large fields and FAA waivers for high altitudes. I'm a pure BP flyer again now and I can fly almost all of my stuff on my own property...BAR to the extreme.

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That's a relief! Thank goodness you're not a newbie! Good luck.

__________________
John Lance Ladd
Yoyodyne Propulsion Systems
Grovers Mill, NJ
Established 1938
lladd.netau.net

I've been doing model rocketry for years, too. Two years.

__________________
John Thro, NAR #84553 SR
I was too old when I started! Now I'll *never* become a BAR!

I'm only sixteen years old, but I was introduced to the hobby when I was very little, I don't even know when, probable when I was like 6 or something. No, I wouldn't dare come on to this form and ask these questions if I was a newbie, that'd just be stupid. It helps to do a little research first. I'm still interested in the store bought engines, estes and what not, but I'd like to get into the experimental rocketry, and it's becoming a real pain to find locations to launch these. But I'll find somewhere, and I'll probably need a waiver. Now that's a thought, graphite nozzles, I need to look into that, it would certainly be lighter then aluminum, but I don't know about cost. I'll look into it.

Hey, Thanks for all the support!

Reloadables have a variety of nozzles. Some of the larger ones have "medusa" nozzles, which are actually a cluster of smaller nozzles sharing one combustion chamber!

If you're primarily interested in the physics of nozzles and such, you should stick with a fuel that is safe, stable, and easy to work with . . . AP, or maybe one of the sugar fuels.

Given a consistent, known-performance fuel, you can then work with new and interesting nozzle configurations. Maybe find out something that benefits the field!

For a basic book on composite motor construction, I strongly suggest looking at "Professer" Terry McReary's book. Don't have the title on hand.