David CL Francis wrote in message ...
On Thu, 12 Aug 2004 at 11:01:06 in message
, Corky Scott
wrote:
The designer of the prop I mentioned wrote in the article about the
fallacy of single bladed prop. Regardless the dubius advantage of
biting into clean air, the problems associated with the unbalanced
thrust produced by the single blade spinning around, despite it being
counter balanced weightwise, are for all practical purposes
insurmountable.

This is successfully been done at model scale, where the effective
diameter is more important and High Mach numbers are not used. This is
especially true of rubber powered models where the high torque needs a
large diameter slow turning airscrew. The mass balance is angled
backwards so the offset thrust can be, to some extent, be balanced.

I have seen a motorglider at a couple of airshows that has a single-
blade counterweighted propeller. In this case the purpose is to make
the engine and prop stowable in the gliding mode. The propulsion as-
sembly is mounted on a mast above and behind the pilot, and pivots
backwards into a well in the fuselage. The drill is to rotate the
prop till the blade is pointing straight down, then lower the mast
assembly into the well and close the bay doors. It obviously works -
I watched the owner take off and fly away. Whether or not it is
satisfactory would be for those who fly it to decide. I haven't
heard any comments either way

David Johnson