Item 1176

DESIGN: Dragonfly ~ Control - Flight - Cyclic - Overview

Drawing:

From SynchroLite:

Longitudinal cyclic ~ Range on rotor blades is +13 to -9 degrees.

Lateral cyclic ~ Range on rotor blades is +8 to -8 degrees.

"It is also observed that a flap frequency above 1/rev significantly reduces the tilt required for a given center-of-gravity offset and hence reduces the cyclic control tavel." ~ [Source ~ HT p.248] Because of the Dragonfly's offset, it may be allowable to make the above angles slight less, if necessary.

May require a forward velocity sensing/control device or pilot operated control to adjust for opposed (differential) lateral cyclic positioning in forward flight.

Lateral Cyclic:

May require a forward velocity sensing/control device or pilot operated control to adjust for opposed (differential) lateral cyclic positioning in forward flight. See B134. Perhaps this could be achieved by raising and lowering the central pivot device.

To negate any chance of lateral cyclic causing rotor - rotor blade clash, the amount of lateral input cyclic should be limited. This should not represent a problem because the large offset will give a fast and strong response.

The absolute maximum lateral horizontal movement at the bottom of a 10" rotor stick is 2.75". This value is for SynchroLite's angular displacement, and the Dragonfly's will be about 25% less; which would be 2.1" (+/- 6º). Shortening the stick will reduce the travel, the angular displacements and make the device more compact.

To eliminate the possibility of blade to hub contact during full lateral cyclic, consider having a differential pitch angle. In other words, when rolling to the left, the left rotor will have a greater lateral pitch (and teeter) than the that of the right rotor. This should be quite easy to do in the linkages. For clearances see; DESIGN: Dragonfly ~ Rotor - Disk - Blade to Hub Clearance

Longitudinal Cyclic:

The absolute maximum longitudinal horizontal movement at the bottom of a 10" rotor stick is 3.75". This value is for SynchroLite's angular displacement, and the Dragonfly's will be about 25% less; which would be 2.8" (+10º -7º). Shortening the stick will reduce the travel, the angular displacements and make the device more compact.

Linkage Methods:

Related Pages:

DESIGN: Dragonfly ~ Control - Flight - Assembly - Phase Lag

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Last Revised: December 4, 2003