taiwanluthiers Posted July 5, 2012 Posted July 5, 2012 75/15/10 willow charcoal, end burner, 1/2" inner diameter, think equivalent to Estes C engine. Flew high and out of sight!
dagabu Posted July 8, 2012 Posted July 8, 2012 Getting there, lets get the guidance stick and nozzle straight next. No CATO, good sound, baby steps and we will have you making #3 motors in no time! -dag
taiwanluthiers Posted July 8, 2012 Author Posted July 8, 2012 What is it meant by #3 rocket? I am familiar with NAR's classification but the firework's classification is not so familiar. Do you mean 3 pound rockets? I actually used 2 skewers taped together as the stick, because I found skewers are too short. I have to go out and get some dowels for the bigger rocket.
graumann Posted July 8, 2012 Posted July 8, 2012 Americans, #3 is how they write 3 pound, the three pounds being some nominal weight of how many lead balls of a certain size fit inside a tube of some length. In this case 3lb being a 1" (inch) diameter rocket.
taiwanluthiers Posted July 8, 2012 Author Posted July 8, 2012 I think I am ready to put on some pyrotechnic payload... any suggestions? Do I make a shell then attach it, or simply place the rocket engine inside a tube and fill that with stars and burst charge?
Potassiumchlorate Posted July 8, 2012 Posted July 8, 2012 (edited) Americans, #3 is how they write 3 pound, the three pounds being some nominal weight of how many lead balls of a certain size fit inside a tube of some length. In this case 3lb being a 1" (inch) diameter rocket. Anglosaxon units are utterly confusing, except for simple things like inches. Inches is actually a more suitable unit for mortar calibers, but other than that I prefer the metric system any day. Edited July 8, 2012 by Potassiumchlorate
taiwanluthiers Posted July 8, 2012 Author Posted July 8, 2012 Anglosaxon units are utterly confusing, except for simple things like inches. Inches is actually a more suitable unit for mortar calibers, but other than that I prefer the metric system any day. Yea, I don't understand the whole thing about gauges... confusing as hell. This goes for shotgun gauges and wire gauges. Rest of the world goes by mm diameter but in America, shotguns are by gauges (how big of a lead ball it is if you made x number of balls that totals one pound), or American wire gauges.
dagabu Posted July 8, 2012 Posted July 8, 2012 Americans, #3 is how they write 3 pound, the three pounds being some nominal weight of how many lead balls of a certain size fit inside a tube of some length. In this case 3lb being a 1" (inch) diameter rocket. I am afraid that both NAR and traditional (not American I am afraid, the English came up with pounds) rocket measurements are incorrect by pyrotechnic standards. NAR motors are measures by impulse only, it has nothing to do with size. Yes, a 25.4mm or 1" ID rocket. Anglosaxon units are utterly confusing, except for simple things like inches. Inches is actually a more suitable unit for mortar calibers, but other than that I prefer the metric system any day. I HATE the standard system here in the USA, I would rather have metric too. Yea, I don't understand the whole thing about gauges... confusing as hell. This goes for shotgun gauges and wire gauges. Rest of the world goes by mm diameter but in America, shotguns are by gauges (how big of a lead ball it is if you made x number of balls that totals one pound), or American wire gauges. Sorry but the Brits came up with gauge measurements, we are just to damn stubborn to change to metric here in the USA like we should. -dag
Peret Posted July 9, 2012 Posted July 9, 2012 (edited) The old rocket measurement system goes back to the days when the Army made fireworks. They used to press the motor inside a metal sleeve to stop it bursting, and their kind of metal sleeves were typically gun barrels. At that time, guns were described by the weight of the ball they fired, thus known as a "2 pounder", "25 pounder" etc. Hence the "pound" weight of the rocket referred to its outside diameter, the gun barrel that it would fit into for pressing. This was already outdated in 1878, when Kentish noted in The Pyrotechnist's Treasury: "Disregard the trade names of pound, ounce, &c., which, now that moulds are dispensed with, are useful only for enabling the makers, from tradition, to understand each other". In another book from the same period, which I can't find right now, a French pyrotechnist observed that if the rockets had to be pressed in sleeves, you had no business using those tubes anyway. American rocket weights seem to have suffered from considerable inflation around the start of the 20th Century, no doubt by advertisers trying to give the impression their "1 pound" rocket was better than their competitor's "8 ounce" rocket, although in fact they were both the same. I think the American standard is now between twice and four times the old British standard. Edited July 9, 2012 by Peret
WSM Posted July 21, 2012 Posted July 21, 2012 Anglosaxon units are utterly confusing, except for simple things like inches. Inches is actually a more suitable unit for mortar calibers, but other than that I prefer the metric system any day. Yes, a 3 pound rocket (make that 25mm ID by roughly 250mm long). They're a great size and use about 110g of propellant. WSM
taiwanluthiers Posted July 21, 2012 Author Posted July 21, 2012 (edited) So when they say 3 pound rocket they don't mean the rocket propellant weights 3 pounds? does it refer to the finished weight of the motor, or the amount of weight that motor can lift, or is it the total impulse of the motor? So my 12mm ID x 3 inch long rocket, what is it called, a 1oz rocket or a 1lb rocket? Edited July 21, 2012 by taiwanluthiers
nater Posted July 21, 2012 Posted July 21, 2012 Your 12mm ID rockets are closest to a 4oz or 1/2 inch rocket. I use 5 inch long tubes for 4oz coreburners.
coldfire Posted July 21, 2012 Posted July 21, 2012 (edited) Ugh! had placed this under the wrong topic Edited July 22, 2012 by coldfire
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