loris94 Posted August 24, 2014 Posted August 24, 2014 Hi I just started making rockets and while reading guides etc... I saw that the Rockets are measured in lbs. I've tried to understand what does 1,2,3 lbs rocket means but I haven't found an answer even tho I think it's related to the lenght and ID. Thank you!
nater Posted August 24, 2014 Posted August 24, 2014 1 lb = 3/4" ID2 lb = 7/8" ID3 lb = 1" ID Traditionally for a cored motor, the tube is 10 IDs long. However, there is some variation in tube length. The pound designation has to do with the weight of a lead ball which will slide down the tube support. This had more meaning a few hundred years ago with munitions than it does today. There has also been a discrepency between the original British designations and US ones. Commercial companies would market rockets to sound larger than they were, and some of the names stuck. I prefer to use the ID in inches being in the US to designate a rocket's size. I think it helps avoid confusion.
dagabu Posted August 25, 2014 Posted August 25, 2014 1 lb = 3/4" ID2 lb = 7/8" ID3 lb = 1" ID Traditionally for a cored motor, the tube is 10 IDs long. However, there is some variation in tube length. The pound designation has to do with the weight of a lead ball which will slide down the tube support. This had more meaning a few hundred years ago with munitions than it does today. There has also been a discrepency between the original British designations and US ones. Commercial companies would market rockets to sound larger than they were, and some of the names stuck. I prefer to use the ID in inches being in the US to designate a rocket's size. I think it helps avoid confusion. Thats what I was told as well but in making lead balls or iron balls, the weights are off. Lost in legend I guess. It's more of a tradition to call them 1#, 2#, 3# etc.
Peret Posted August 25, 2014 Posted August 25, 2014 It goes back to the days when the people who made fireworks were the British Army artillery company (the Woolwich Arsenal in England) and they used gun barrels as sleeves for pressing. A "One Pound" fit inside the barrel of a 1-pounder gun, etc. The projectile may have been lead, or iron, or a cylindrical shell - the actual weight really had no bearing on the matter, because everyone knew the caliber of a "1 pounder", "2 pounder" etc and it was only the caliber that counted. Also note, it fit the OUTSIDE diameter of the tube, not the ID. The connection to gun calibers was lost after 1900 and in America, considerable "inflation" took place, probably because of false advertising. Eventually, an American 1 pound rocket was about 1/4 the size of a British 1 pound rocket. It's now completely disconnected from reality and only survives as a tradition among fireworkers. To be sure of anything, don't trust the weight designations and always go by inside diameters.
loris94 Posted August 25, 2014 Author Posted August 25, 2014 Ok thank you very much for the explanation guys
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