"Red" wrote in message ...
I like the idea of compressed gas for the pre-rotar! That might be do very
able...

Where is the gas going to exit...at the tips of the blades, I'm
presuming? Now you have plumbing running through the blades plus a
lot of plumbing and complexity where the gas enters the roots of the
blades. Gyro blades are hard enough to balance as is, with a gram
added here and there via powdered lead or a tiny washer or 2.

I got a long ride in an Air & Space and the blades are depitched to
zero until about 300+ rpm, I believe. Then the blades are quickly
released to their normal pitch for the jump. I doubt you'll get
anywhere leaving them pitched and spinning them up, even to a high
number. Otherwise A & E would have skipped the complexity of being
able to depitch and repitch the blades rapidly if all it took was some
rpm. Then you'd have a "helicopter" spinning wildly out of control as
soon as it left the ground because it doesn't have any means to
counteract the torque. To those that think it's doable...do it and
then show us how you did it. We'll all be anxiously awaiting.

Ken J. - SDCAUSA




"sanman" wrote in message
om...
Hi,

I'd done some reading about pre-rotators for gyroplanes which can be
used to give them a jump takeoff. I was wondering if any of them have
tried using compressed gas to power the pre-rotator?

I got the idea after reading these links:
http://www.howstuffworks.com/question133.htm
http://news.bbc.co.uk/1/hi/world/africa/988265.stm
http://auto.howstuffworks.com/air-car.htm
http://www.evworld.com/databases/sho...=news190503-04

Gee, now that I think about it, why couldn't compressed air even be
used to power the gyroplane pusher prop during regular flight?

An onboard compressor could even be used to compress air into the
cylinder in the first place. Liquified nitrogen gas can store a lot of
energy, pressure-wise -- more so than what a battery could store. That
compressor could be reversible as a motor.