- #1
monkeybizz
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Hi, why isn't anyone out there making a jetboard, based on an old experiment carried out by engineer Charles Zimmerman?
In 1959, the man tethered a US airforce pilot and made him stand on a jet of air for minutes on end.
Two flexible air hoses connected to two tanks of compressed air (at 20bars only) made a T connection with a short nozzle of 3 cm diameter that poked down through the center of an ultra simple plaform. The pilot stood on it and moved the board simply by instinctively balancing himself. He managed to get out of ground effect and kept a stable hover for a very long time. Later on, he succeeded in moving horizontally at nice speeds, with ease.
They tested the thing outdoors and breezes or even gusts of wind didn't affect the stability of the platform. Zimmerman proved that kinaestethic control (or "thrust vector flight") worked very well. Man's keen sense of balance was all you need to move around on a jetboard.
A quote from an old article:
It worked beyond the best anticipation of his theory. Balance control through the feet was so instinctive that it operated below the level of conscious thought. He went up and experienced it again. Paul Hill tried it. Testing further, they found that besides hovering perfectly by not thinking about it, you could control consciously, too--but here you tended to teeter your feet unnecessarily in a flurry of overcontrol.
...
News of these activities at NACA got around in channels that were entitled to receive confidential government information. Visitors came to "ride the board." Most of them did well. A few at first swung like flopping fish on the safety
line. It wasn't a question of skill-which wasn't needed--but confidence.
Later on, Zimmerman made a few flying platforms (with gas engines and rotors) for the US Navy (they worked amazingly well), and Hiller picked up on the idea as well, and added his ducted fan.
Zimmerman tried to make a jetboard that could carry its own compressed air. But tanks at that time were way too heavy (made of steel) and didn't contain that much air (and only at 20bar). Today, there are lightweight, ultra-strong tanks used in transport vehicles that can hold air at pressures of up to 300 bars easily (the ones used in buses and natural gas vehicles).
So WIBNI to make such a jetboard? It shouldn't be that difficult, I think (even though I'm not an engineer).
Such a jetboard would look like a simple "flying platform" (ducted fan, with the duct containing the compressed air), and the only control you'd need would be a handle to control the airflow. Lateral movements would be controlled entirely kinaesthetically. In the middle of the duct, you have a small platform on which you stand, with under your feet a few air jets.
Advantages:
-No engine
-No moving parts
-No rotors
-Very very lightweight (compared to flying platforms with engines)
-A lot of fun
Some pics:
Hiller's ducted fan: http://www.aardvark.co.nz/pjet/images/hiller1.jpg
Colonel Henderson standing on a jet of air: http://www.howtoadvice.com/Image/Photo/ColDavidHenderson.jpg
Simple but heavy flying platform, commercially available: http://www.flying-platform.com/
What do you think? Is this doable (this is a boy's dream, I know)? Or should I just go back and watch "Back to the Future: Part 2", once more?
In 1959, the man tethered a US airforce pilot and made him stand on a jet of air for minutes on end.
Two flexible air hoses connected to two tanks of compressed air (at 20bars only) made a T connection with a short nozzle of 3 cm diameter that poked down through the center of an ultra simple plaform. The pilot stood on it and moved the board simply by instinctively balancing himself. He managed to get out of ground effect and kept a stable hover for a very long time. Later on, he succeeded in moving horizontally at nice speeds, with ease.
They tested the thing outdoors and breezes or even gusts of wind didn't affect the stability of the platform. Zimmerman proved that kinaestethic control (or "thrust vector flight") worked very well. Man's keen sense of balance was all you need to move around on a jetboard.
A quote from an old article:
It worked beyond the best anticipation of his theory. Balance control through the feet was so instinctive that it operated below the level of conscious thought. He went up and experienced it again. Paul Hill tried it. Testing further, they found that besides hovering perfectly by not thinking about it, you could control consciously, too--but here you tended to teeter your feet unnecessarily in a flurry of overcontrol.
...
News of these activities at NACA got around in channels that were entitled to receive confidential government information. Visitors came to "ride the board." Most of them did well. A few at first swung like flopping fish on the safety
line. It wasn't a question of skill-which wasn't needed--but confidence.
Later on, Zimmerman made a few flying platforms (with gas engines and rotors) for the US Navy (they worked amazingly well), and Hiller picked up on the idea as well, and added his ducted fan.
Zimmerman tried to make a jetboard that could carry its own compressed air. But tanks at that time were way too heavy (made of steel) and didn't contain that much air (and only at 20bar). Today, there are lightweight, ultra-strong tanks used in transport vehicles that can hold air at pressures of up to 300 bars easily (the ones used in buses and natural gas vehicles).
So WIBNI to make such a jetboard? It shouldn't be that difficult, I think (even though I'm not an engineer).
Such a jetboard would look like a simple "flying platform" (ducted fan, with the duct containing the compressed air), and the only control you'd need would be a handle to control the airflow. Lateral movements would be controlled entirely kinaesthetically. In the middle of the duct, you have a small platform on which you stand, with under your feet a few air jets.
Advantages:
-No engine
-No moving parts
-No rotors
-Very very lightweight (compared to flying platforms with engines)
-A lot of fun
Some pics:
Hiller's ducted fan: http://www.aardvark.co.nz/pjet/images/hiller1.jpg
Colonel Henderson standing on a jet of air: http://www.howtoadvice.com/Image/Photo/ColDavidHenderson.jpg
Simple but heavy flying platform, commercially available: http://www.flying-platform.com/
What do you think? Is this doable (this is a boy's dream, I know)? Or should I just go back and watch "Back to the Future: Part 2", once more?
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