AboutDave Landgraf Expertise I will be happy to take on questions about low-power rocketry in general, including rocket design, operating characteristics of blackpowder motors, low-power motor selection, rocket construction, aerodynamics, parachute and streamer duration competition, boost glide (and a little rocket glide), egg loft, altitude competition, and scale competition. I can help you with Barrowman stability calculations, but I am not a rocksim user. I know the basics of mid-power rocketry and small composite motors but I don't fly them much (I'd rather stretch my money by sticking with low-power). I believe I can explain many concepts in a way that just about anyone can follow (and maybe even over-explain?). I absolutely do not mind "newbie" questions one bit; the only bad question is the one you don't ask!
Experience I have flown model rockets for some 40 years, including a few early years of NAR competition. I have been active at the local club level as well as in the NAR. I enjoy designing and developing unconventional designs (the kind of thing you look at and say "it won't fly!").
Organizations National Association of Rocketry
Publications Model Rocketry (magazine)
Education/Credentials I am an aerospace engineer who has worked professionally in the field for over 30 years. I have worked often with local school, church, and scout groups to lead introductory build-n-fly sessions.
Question i am building a prepackage rocket and it talks about lbs of thrust...and i am not been able to find this on the net, can you please explain it to me
Answer Hi Connor,
If you are asking about model rocket motor thrust, most blackpowder motors (like those made by Estes or Quest) can create several pounds of thrust force but can only do this for a fraction of a second.
Model rocket motors are designed to produce an initial high thrust peak to get the model rocket moving off the launcher, usually followed by a reduced level of sustaining thrust to help the model rocket cruise on up to a significant altitude. You can get a lot of detailed information on the time-versus-thrust characteristics of model rocket motors at the NAR (National Association of Rocketry) Standards and Testing website: http://www.nar.org/NARsandt.html
Scroll down to the bottom (where it says 'Related Information') and click on the line that says 'List of motors approved for consumer use in the US'
That should get you to a webpage titled 'NAR Certified Motors' and you will find a long list of motors below. Select a motor (and click on it) and you will find lots of detailed technical motor data.
Part of the data will be a time-thrust graph for that specific motor as measured on an instrumented thrust stand. You can see the initial thrust peak on the graph, and the reduced sustaining thrust level.
