B287

DESIGN: UniCopter ~ Rotor - Blade - VR-modified

Outside Helicopter

UniCopter

Working Thoughts re Mockup as at March 23, 2004:

The blade is to be extremely rigid, therefore;

Locate the feathering axis at the root, chordwise at the thickest location on the upper portion part of the blade, which is 33% of chord. This will give an optimum spar thickness. Locate the feathering axis at the tip at 25% of chord. This is an 8% difference and it will put the location at a theoretically ideal 27% of chord at 0.75 R. See where Robinson put their feathering axis, out of curiosity.

??? Locate the feathering axis, above the chord line. Locate it midway between the chord line and the middle of the thickness, at least at the root end. This will make the centroids of the upper and lower spar flanges more equal. It should also increase the pitch angle where the blade has a neutral pitch tendency.

The root chord is 17" and the tip chord is 6". The chord taper is 11"/9' = 1.22" per foot.

Last Revised: September 25, 2011