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DELETED (Inactive)
   
191 Posts |
Posted - Feb 17 2003 : 2:41:09 PM
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Man you are an idiot if you purchase that. Do you look in the description? "The empty weight is about 150lbs" He talk about FLYING JETPACK so are you able to have that weigh in your back?
And he tell ofcourse that they have the plan an he plan to build it's own too. lolll thay have a lots of crap in the internet. But it's cool to see the imagination...
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Aaron Cake
Administrator
    
Canada
6718 Posts |
Posted - Feb 18 2003 : 10:13:36 AM
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I tried the jet pack thing 10 years ago. I ended up dumping 10 LBS of propane on the ground in about 10 seconds. Truly spectacular, but almost killed myself in the process. Unfortunately, I do not have any pictures as digital cameras did not exist back then. Not something I would recommend. Though it had no chance of working as I was missing a few concepts (such as thrust).
Really, if I was going to make a jet-pack today, I would build it around two monster truck turbochargers (T-88s or T104s or the like). I would plumb the compressor output to the turbine inlet and add a fuel injector and spark plug. Probably run it on diesal, kerosene or just jet fuel. Oil and water systems for the turbos are pretty easy to make (small electric oil pump and water pump, with small resevoirs and coolers). Connected to the turbine housing output (ie. the exhaust side) would be an exit orifice, with adjustable "fins" on the output to direct the thrust. The turbine wheel (blades) would have to be modified to be more thrust happy and actually produce thrust out of the exhaust outlet instead of trying to minimize this (as in an automotive application). I would imagine that two large turbos should produce enough power to lift a person.
The pack itself would be mounted on the back, with a kevlar/asbestos coated flame guard to protect the legs. Stabilizing wings would probably be required. The only issue is that these turbines would just plain drink fuel, so flights would be short based on a reasonable amount of fuel to be carried. Starting would be annoying as some good high pressure compressed air would be needed to spin the compressor up to around 30,000 RPM to produce enough boost to start the turbine.
Just an idea. 
Did a search on homemade jet turbines and came up with these:
http://mdavis19.tripod.com/turbine/index.html http://www.gasturbine.pwp.blueyonder.co.uk/page1.htm http://www.reality.demon.co.uk/gasturb.htm http://www.users.zetnet.co.uk/gas/dtt.htm http://home.earthlink.net/~turbochris/index.html
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191 Posts |
Posted - Feb 19 2003 : 1:10:04 PM
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Aaron wow you give me a new project to do this summer. Not a jet pack to kill my self but just a turbo reactor for make a litle go cart with a lots of boost..... cool.
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Aaron Cake
Administrator
    
Canada
6718 Posts |
Posted - Feb 19 2003 : 1:50:48 PM
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Actually, now I am seriously thinking about the jet pack...
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191 Posts |
Posted - Feb 19 2003 : 2:19:49 PM
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The problem of making it as a jet pack, is not the fire but the heat....
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191 Posts |
Posted - Feb 19 2003 : 2:20:51 PM
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I forgot to ask you! What happen if your motor faild in the air????? Hope you will think about it
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Aaron Cake
Administrator
    
Canada
6718 Posts |
Posted - Feb 19 2003 : 4:41:28 PM
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quote:
The problem of making it as a jet pack, is not the fire but the heat....
True, but heatshields are easy to make. This summer I designed a heat shield for the turbo on my car. It was effective enough that after hours of high-boost driving I could still place my hand inches above it without feeling any discomfort. An air gap between two pieces of metal is remarkably good at insulating heat transfer.
quote:
What happen if your motor faild in the air????? Hope you will think about it
I would fall. That much is obvious. But a small parachute could easily be built into the pack, or worn accross the chest.
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191 Posts |
Posted - Feb 20 2003 : 10:32:28 AM
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Parachute.. Hope that you will take the mass of the hole things in your mind before buing it.
You know if it's work, I will be the first one to see that. I'm in Physics so gravity is something cool for me.
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Aaron Cake
Administrator
    
Canada
6718 Posts |
Posted - Feb 21 2003 : 10:46:04 AM
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Well, the parachute would simply be large enough to prevent death, not necessarily injury. So it would be rather small, and the fall rate would still be pretty high.
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BEatonNo1
Nobel Prize Winner
    
USA
1133 Posts |
Posted - Mar 17 2003 : 4:29:57 PM
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the jet pack in one of the James Bond movies was actually real. I saw it fly on TV. It works differently than what yall are proposing. It uses a compressed gas and has a top frame that steers it by moving the jets. the flight time was i think less than 2 min but it looked cool.
I dont think that you could use a gas turbine because it wouldnt have a high enough trust to weight ratio. usually gas turbines are used for their torqe not their thrust.
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191 Posts |
Posted - Mar 18 2003 : 11:41:35 AM
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LOLLLLL Hey whats about adding a fan in front of it.... Like the real jets.......
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Aaron Cake
Administrator
    
Canada
6718 Posts |
Posted - Mar 18 2003 : 3:02:12 PM
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To produce thrust you would modify the turbine wheel.
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BEatonNo1
Nobel Prize Winner
    
USA
1133 Posts |
Posted - Mar 18 2003 : 5:25:53 PM
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what about gas, the flying of it would be pretty touchy. as you progressed in flight time their would be less gas so you would need less thrust. this happens in other aircraft but in the jet pack it would be more noticeable because it would suck the gas so quickly. another problem would be that the liquid gas would make the pack unstable as you come to a stop or jerked suddenly, because it would slosh around. this would be especialy a problem in the jet pack because if your pitch changes too much you would rocket into the ground (at that point the parachute wouldnt help:-<) if you used gas you would have to have a buch of little cells. therefore it would probably be better to use propane, which would also perform better and be lighter.
Edited by - BeatonNo1 on Mar 18 2003 5:59:27 PM |
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BEatonNo1
Nobel Prize Winner
    
USA
1133 Posts |
Posted - Mar 18 2003 : 5:43:59 PM
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www.gas-turbines.com/nt5/nt5.htm look how big this gas turbine is and it only gets 60lbs of thrust. I really find it hard to believe that you can modify a smaller one to provide enough to lift you off the ground. you would be better off using the torq instead
Edited by - BeatonNo1 on Mar 18 2003 5:54:57 PM |
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Aaron Cake
Administrator
    
Canada
6718 Posts |
Posted - Mar 20 2003 : 10:32:38 AM
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OK. Instead of building your own gas turbine, either build or buy a "real" jet engine. Should not be hard to find.
Sloshing fuel is easy to solve. Just use a baffled tank.
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