Morgans wrote:

Eliminate the moving prop, as thrust for ground propulsion. Doing so will
solve the acceleration problem. The dust it would throw up will make it
very unpopular, if not outlawed. The guard would have to have bars close
enough together to keep even a finger from getting into it, and most likely
even hair.

I don't know, if you were to go the ducted fan route you could have the
inlet and outlet of the duct far enough from the prop that the guard
wouldn't have to be all that restrictive and it could be easily removed
for flight. Also the ducted fan would provide more thrust for the same
horsepower if I'm not mistaken. If it is a constant speed fan, I bet
you could get acceptable acceleration out of it. However the dust it
would throw up and noise would probably be big down side. You may be
able to minimize the dust problem by mounting the fan high on the
vehicle. But the noise would be pretty bad still.

I really don't like the idea of having 2 power plants but if you are
going to drive the wheels I don't see that there is a practical
alternative.... or wait.... maybe hydrostatic drive off the same drive
shaft as the prop. A lot of research is going into hydrostatic
transmissions these days. The can be pretty compact but are generally
heavy. Since you only want around town slow driving capability, maybe a
compact light weight engine with low gearing would fit the bill. If you
could make some use of that power plant during flight, so it wasn't
completely dead weight that would be nice..... maybe have it drive all
the engine accessories for flight and ground use.


--
Chris W

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