Seeing Thingiverse Challange #CatchTheWind the first thing that came to my mind was Leonardo Da Vinci's flying machine and his fascination with the wind altogether.
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So I made his design (with a few intentional alterations) into model that is easy (no support needed, custom brim already incorporated into the model) and quick to print. Every part except body (2 h) needs approximately 1 hour to print.
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The wings are printed like a flat surface but are bend according to the main ribs when assembled. The wing span is 65 cm.
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The body is designed so that is aerodynamic and lets the 4 screws that hold the tail and main ribs to the body to penetrate making it ideal for a variety of add-ons.
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You can now print it, assemble it and have your own DaVinci's flying machine that can actually fly like a kite.
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No additional materials needed (the wings are printed so that they are not able to loosen up, they are light, strong and flexible so they can be bended), just print all the parts, screw everything together (the wings are holding themselves tight to the main ribs even without the screws) add some nylon threads and make it fly!
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UPDATE 1

Added STL files Left wing_big and Right wing_big for printing the wings in one piece on large printers.

UPDATE 2

Uploaded new files for large wings (Left wing_big_new and Right wing_big_new). The old ones were deleted - parts were not modeled correctly.