"Rip" wrote in message
...
Phil, sorry for the tongue-in-cheek answers. It's just that there is
very little new under the sun. In my admittedly misguided youth, I built
a one man helicopter, with the tail rotor driven exactly as you suggest
(variable speed hydraulic motor driven by a pump from the main engine, a
wankel from a snowmobile). I never had the balls to take the contraption
out of ground effect, but it did work. Hydraulics can be very efficient
at transporting considerable amounts of power from one end of a tube to
the other, but as others have pointed out, tend to be very heavy.
"Lightweight" is a relative term when speaking of industrial machines
(look at all of the effort involved in certifying aviation diesels, as
one example).




Not a problem. When I say "lightweight" I mean in comparison to most
motors. I see many that are 50-100 (or more) pounds. To me, a hydraulic
motor than weighs in at 20 lbs, spins at the proper speed without a gearbox,
and provide 100+ ft lbs of torque, is lightweight. Eaton *claims* 90%
efficiancy.


And I don't blame you for not getting out of ground effect. What was that
wankle good for... 50 hp?