[Tom Stanton] Builds An Osprey

The V-22 Osprey is an aircraft like no other. The tiltrotor multirole military aircraft makes an impression wherever it goes; coincidentally, a flight of two of these beasts flew directly overhead yesterday and made a noise unlike anything we’ve ever heard before. It’s a complex aircraft that pushes the engineering envelope, so naturally [Tom Stanton] decided to build a flight-control accurate RC model of the Osprey for himself.

Sharp-eyed readers will no doubt note that [Tom] built an Osprey-like VTOL model recently to explore the basics of tiltrotor design. But his goal with this build is to go beyond the basics by replicating some of the control complexity of a full-scale Osprey, without breaking the bank. Instead of building or buying real swash plates to control the collective and cyclic pitch of the rotors, [Tom] used his “virtual swashplate” technique, which uses angled hinges and rapid changes in the angular momentum of the motors to achieve blade pitch control. The interesting part is that the same mechanism worked after adding a third blade to each rotor, to mimic the Osprey’s blades — we’d have thought this would throw the whole thing off balance. True, there were some resonance issues with the airframe, but [Tom] was able to overcome them and achieve something close to stable flight.

The video below is only the first part of his build series, but we suspect contains most of the interesting engineering bits. Still, we’re looking forward to seeing how the control mechanism evolves as the design process continues.

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Building A Tilt Rotor UAV

We see a lot of quadcopters, and even the occasional octocopter around here. But this build does it with just two propellers. It’s a tiltrotor build which allows the two upward-pointing propellers to tilt forward and backward. The real world equivalent of this UAV design that pops to mind is the V-22 Osprey.

The motors are mounted on a beam running perpendicular to the direction of travel. Each of them is mounted on a bearing which can be rotated by a servo motor. They rotate independently of each other, which allows for yaw. Of course roll is controlled by driving the propellers at different speeds and pitch is adjusted by tilting both mounts at the same time.

[Stephen] mentions that the tiltrotor design has several advantages over its relatives that use more than two props. This design costs less to build, uses less electricity, and makes for an easier autopilot implementation. If you want to see it in the air, don’t miss the clip after the break.

This is just the second tiltrotor build we remember seeing. The other one was a Halloween prop.

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