AboutJames Bell Expertise I am a member of Tripoli Rocketry Association, and am certified to fly hi power rockets. I can answer questions anyone may have about design, materials selection, stability calculations, motor selection, altitude and performance predictions, and parachute and recovery options.
Experience I make my rockets from existing kits or parts readily made through commercial channels. I do NOT make my own motor propellants (they are challenging enough even for the companies that do this for a living), and I do not advocate making rockets using "typical household item" such as paper towel rolls.
Question I need to find the C/G of my Level 1 rocket.
I do not have a level 1 certification yet.
How do I estimate the engine weight, I can not buy one?
Can you give me an engine weight of a H or I engine?
What is the easy way to determine C/P for my 6 foot samurai rocket?
Answer Bill -
You ask questions that are both involved and complex. Here is the best way to tackle them ... I have a website set up at ...
On the page you will find a downloadable programs to help you determine the predicted altitude of your rocket, along with a CP (center of pressure) calculator. Knowing the location of the CP is as important as the CG.
I would also suggest you look into G. Harry Stines book, THE HANDBOOK OF MODEL ROCKETRY. This book spells out everything you need to know about making your own rockets.
Finding the CG of your rocket is relatively simple ... pack it up with parachute and motor (as it would be ready to fly). Lay it on its side and put it on a pencil (obviously off the ground so the fins don't interfere). Find the exact point at which it is balanced, and that's your CG.
