This is Helios 3. It is a 1/2 inch diameter by 18 inch long steel tube with an end cap, fins and an end cap with a hole drilled out. It is powered by 30 grams of Rocket Candy (Sugar, Potassium Nitrate, and Corn Syrup.) This is the third rocket I've built. The first one was a copper tube that exploded on the launch pad, and the second can be seen here
. I have learned a lot since Helios 2 which includes better ways to make the fuel, more on the physics of fins, and most importantly, how to make it go higher! I did mess up when building the rocket so it will never fly straight again. When I was cutting notches in the tube to put the fins in, I accidentally cut the whole way through on the one fin. The pressure blew it out in the first launch, and by the last launch it was spiraling out of control severely.
65% KNO3 (potassium nitrate, saltpeter, stump remover, fertilizer) - about 4 parts by mass
17.5% Sugar - about 1 part by mass
17.5% Karo Syrup (light corn syrup) - about 1 part by mass
I just use the ratio: