Amateur rocketry is a fascinating and rewarding pastime. It is differentiated from HPR (High Power Rocketry) in that we build our own rocket motors as well as other complex flight systems. Most people who get into it, do it because of the technical challenges it presents, as well as out of necessity to custom tune rocket motor performance to a particular mission profile. Some, such as myself, develop rocket propellants and motors and hardly ever fly anything at all. However, the rewards of discovery and continuous learning in multitude of technical disciplines is what binds all amateur rocket scientists!
It is a misconception that it is less costly to build your own solid rocket motors as opposed to purchasing them. In actuality, while a single homemade motor cost may indeed be lower, the expense of bulk purchases, equipment, startup materials, fixtures as well as the testing itself by far out paces any real savings - unless you plan to fire off a whole lot of motors. So, if you are an HPR buff and savings are your real goal, you may want to reconsider.
However, if you do have the fire in your belly... let me share some of my data with you. I do want to point out that I have no business interests connected to rockets, nor do I belong to any organizations (no, not even TRIPOLI). Just one guy playing with AP...
Also, let me point out that this hobby is most definitively a HAZARDOUS pass time. Rocket motors are in essence just very well controlled pipe bombs. So if you do not have a technical background (in the right disciplines, too), or are not sure of what you are doing and intend to mix propellant much like when cooking a dinner and then stuff it down a pipe - DON'T!!! However, if you do think that you are qualified, and have read and understood technical texts such as Propulsion Elements by G. Sutton - READ ON.
To start off, let me offer some safety tips. The fact that I am so concerned about people blowing themselves up should further emphasize the fact that this is a very DANGEROUS hobby. This page is not intended for novices.
All the information presented here is intended to be used for educational purposes only! I do not guarantee and can not be responsible for the validity of any data presented here.
This article shows how to design a fixture for statically testing your motors. Also, here you will find some 'action' pictures.
Temperature controlled, vacuum enclosed propellant mixer.
Article by Jerry Irvine, describing construction of a simple, yet effective, launch controller and pad.
STRAND BURNER - Comming Soon (to the web near you)!
Various propellant formulations, including ballistic data (burn rate...), and so on. If you do use any of them I would be interested in finding out how it worked out for you. Also, if you know of any reasonably well characterized propellants that you would like to share with the rest of us, e-mail me, so that I can include it here.
So you want to develop your own solid rocket fuel? Here are few contour graphs depicting computer predicted specific impulse performance for various propellant formulations. The propellant is set to a combination of metal fuel and binder, the remainder being the oxidizer. Predictions are offered for chamber pressure of 250, 500 and 750 psia and optimally expanded nozzle (at sea level). These charts are intended to be used only as a starting point in development, although I have confirmed that their validity in practice is very close indeed. I have only included shifting specific impulse (Isp) data. If there is sufficient interest I may post other parameters (Tc, M, C*, cp/cv ...) as well as other oxidizer/metal/binder combinations. Or you can try e-mailing me with your suggestions.
Performance estimates of selected Firefox propellant formulations.
*Due to copyright issues I can only list the predicted performances for chosen fuels. You will have to purchase "Plastic Resin Bonded High Energy Rocket Fuel Systems" by Garry Purrington from Firefox Enterprises Inc., (208) 237-1976, to find out about the formulations themselves. This booklet also contains wealth of information on various binders, curatives, modifiers, etc..
INVITATION TO ALL !
If you have any useful tips regarding amateur rocketry, contact me and I will consider posting them in the above section: USEFUL TIPS. This can be information regarding homemade igniters, nozzle materials, flight electronics, and pretty much anything that you have pioneered in the course of your activities. It does not need to be real fancy; Remember, it's the small stuff that makes the difference!
Questions? Comments? Suggestions?
This page has been accessedtimes
since 20 Aug. 1996.
Last update on 07-Sep-96 - Copyright © 1996 Chris Krstanovic (WR1F)