Thread: Discussion Monotwirl Electric Autogyro
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Old Dec 30, 2006, 04:22 PM
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Salisbury,England
Joined Jan 2005
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Hi Bob,

In the first movie, the rotor mast angle was at 5 degrees aft. The C of G was about 1 inch forward of the rotor axis and the 3mm thick depron rotor blades were covered in paper top and bottom, along with a double spar made from lollipop sticks - very stiff indeed. You can probably see that the rotor speed was quite low, round about the 200 rpm mark, and it needed almost all of the rotor tilt control to the right when coming in to land.

In the second movie, the rotor mast angle was changed to 10 degrees aft, the autogyro now balanced level when held by the rotor pivot and the rotor blades were now simple 3mm depron with a 3mm x 3mm spruce spar. Additionally, the blade pitch was slightly more negative, achieved by adding 1/16 balsa plates underneath the inboard trailing edge of the blades. The rotor has built-in flexibility/flapping and, as a result, needs little or no lateral correction throughout the speed range and is very easy to build.

In both cases the rotor rotates CCW as seen from above.

There were a number of iterations in between the two movies of course, but I have not made any further changes since the second movie.

Hope this answers your questions,

Al
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