Here is an animation I made for my Lego Ideas project, Air Galleys, using POV-ray:
See more renderings and the full project at:
https://ideas.lego.com/projects/108617
The most difficult part to animate was the flapping motion of the wings. At first I considered using a simple sine curve for the angle of the wings but the results were unsatisfactory. I ended up modeling the physical constraints of the model; as the wing shafts rest on the bottom of the ports they protrude from, their bases rotate with the gear they are connected to. As their contact point on the gear drops beneath the ledge of the port, the wings rise slowly and then quickly fall again as the opposite occurs.
Here is a diagram: