mdawson Posted May 17, 2009 Share Posted May 17, 2009 I have a lot of 3"id tubing. What kind of tooling would I need to make these into rockets? They range in length from 24" to 48". I can make them any length I guess. Link to comment Share on other sites More sharing options...
Swede Posted May 17, 2009 Share Posted May 17, 2009 WOW that would be a big rocket! You'd need a monstrous press, and a CATO from something like that would be impressive, to say the least. What is the wall thickness? Is it spiral, or parallel wound? You have to decide what sort of fuel you'll use, BP or whistle, as the tooling will vary. An end-burning BP rocket would probably be forgiving, but I don't know if the thrust would be adequate for such a large rocket. I think there's a guy who makes gigantic whistle rockets... there were some videos posted a while back. Link to comment Share on other sites More sharing options...
Yankie Posted May 17, 2009 Share Posted May 17, 2009 (edited) You could probably make the tooling from wood, infact it would be the only way unless you can afford some 3" metal rod, and then turn it down to the dimensions you need. I have been planning to make a 3" ID rocket myself actually. I was going to use KNSU dry propellant, though R-candy would be alot easier as you could just pour it into the casing then use a rod to form the core. I am a bit worried about cooking that amount of fuel though. Edited May 17, 2009 by Yankie Link to comment Share on other sites More sharing options...
mdawson Posted May 17, 2009 Author Share Posted May 17, 2009 I believe the wall thickness is around 1/4". I want to make whistle rockets and I want to try and get it right the first time around. I have never tried a rocket. I feel that the tubing I have is adequate. It is the tubing left behind after blueprint paper runs out. As I stated before they come in lengths from 24"-48". Sometimes they get a little bigger. I have an unlimited supply of tubes. I would like someone that has somewhat more experience than myself to help me out with this. Swede it is spiral wound. Link to comment Share on other sites More sharing options...
tentacles Posted May 17, 2009 Share Posted May 17, 2009 1/4 wall thickness isn't going to be hefty enough - I'd expect even NEPT tubes with those specs would fail for all but the limpest fuels.. The tubes cplmac uses are 1/2-5/8" wall carpet tubes, immensely strong stuff. He makes cored whistle rockets out of them, and they are expensive to say the least.. I believe he stated 3 lbs of whistle mix per rocket? And he has lifted a 12" shell on one - there's a video around here somewhere. One way to make tooling would be to use pipe or rod of a smaller diameter, say 1.25", and put a slug of 3" round on the end to serve as the rammer. Fancier designs could use pipe to accommodate a core, etc. No matter how you look at it, though, it would be expensive in materials alone. Link to comment Share on other sites More sharing options...
mdawson Posted May 17, 2009 Author Share Posted May 17, 2009 So 1/4" won't do it? Is it not strong enough to hold the mix needed to get it air born? Or is it too thin to as it would burn up before it had a chance to get high enough? I am all ears. I am the student. Could I not reinforce the out side of the tube with something? Link to comment Share on other sites More sharing options...
FrankRizzo Posted May 17, 2009 Share Posted May 17, 2009 So 1/4" won't do it? Is it not strong enough to hold the mix needed to get it air born? Or is it too thin to as it would burn up before it had a chance to get high enough? I am all ears. I am the student. Could I not reinforce the out side of the tube with something? Maybe if you rolled the outside with a few layers of fiberglass, you'd get the required tensile strength. Doing that, however, seems to defeat the purpose of the tubes being cheap and readily available to you. Another thing to think of is that the amount of comp you need to load one of those monsters is going to cost you $$. Use them as 3" mortars or bottom-shot cans instead. Link to comment Share on other sites More sharing options...
mdawson Posted May 17, 2009 Author Share Posted May 17, 2009 Maybe if you rolled the outside with a few layers of fiberglass, you'd get the required tensile strength. Doing that, however, seems to defeat the purpose of the tubes being cheap and readily available to you. Another thing to think of is that the amount of comp you need to load one of those monsters is going to cost you $. Use them as 3" mortars or bottom-shot cans instead. I so want to make some rockets. How much do you think to make some screamers? Link to comment Share on other sites More sharing options...
Arthur Posted May 17, 2009 Share Posted May 17, 2009 (edited) The (UK) typical retail rocket has a stick not more that 20" long and by the time the payload has fired there is little left to come down. BUT with a three inch tube you will want a stick like a broom handle and the casing itself could weigh 5 - 10 Lbs Be very careful that you have space to test these as they will be lethal as they descend. And if the first few CATO then the neighbours for MILES wil know about it! Remember that rockets with sticks tend to fly into wind, one this size could fly a mile into wind, you need to be very sure it's a safe place to fly from. Sadly IMO the tubes you have are possibly too thin to withstand the pressure inside the burn cavity and you are likely to have more CATOs than good flights. Edited May 17, 2009 by Arthur Link to comment Share on other sites More sharing options...
Swede Posted May 18, 2009 Share Posted May 18, 2009 It's cool that you have a supply of free tubes, but being thin-walled and spiral-wound, I really think they will not make suitable rockets. As the other guys have already mentioned, the cost to pack the free tube with whistle will be very high, making the savings not so great. In other words, if you're going to make big rockets, it'd be more economical in the end (less CATO/failure) to start with appropriate tubes. I'm sure there are other options for the tubes. Maybe a big fountain or mine? I've messed around with smaller rockets, and to get good, consistent performance is harder than it looks. These guys make it look easy. Even a 4-ounce BP rocket CATO is M-80+ in volume, very loud. If a 3" ID whistle rocket cato'd, it'd be incredibly loud as well as dangerous. Rockets have an evil habit of flying (often horizontally) for a second or two before exploding. Have fun but be careful. Link to comment Share on other sites More sharing options...
mdawson Posted May 19, 2009 Author Share Posted May 19, 2009 OK OK OK I guess I will have to use the tubes I have for blasting rocks, stumps, and the occasional beaver dam. Thanks for all the info. Link to comment Share on other sites More sharing options...
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