Day 3: Birds

For the first half of class today, we started a new topic: creating bird-like machines. They have to have some sort of body and wings that flap when a crank is turned. After quickly Googling birds, I came up with this model:

In this model, the cam on top spins around, and each time around it pushes a piston attached to the wings down. As the piston moves down, the wings move up. The weight of the wings naturally makes them fall back down.

To illustrate this point to my partner, I ran around like a crazy person and quickly set up a LEGO model:

Although the model is a bit crude, it works exactly the way it should. In the bird, the cam (which is a oblong shape) would go where my hand is in the photo above. Here is a video of my "bird" in action:   We had to come up with 4 more designs, each with a different mechanism. These first three pictures use a "chomping" motion. Two rods are joined together at a point, allowing them to open and close in a chomping motion. A cam  pushes on one of the rods, making the "mouth" open and close. The rod that moves is attached to another by a hinge and as the end of the rod moves down, the second moves up, and vice versa. This simulates a flapping motion. These next three pictures are another design, this time using an axis to turn the wings up and down. We need to iron out some kinks... These two pictures are diagrams of our fourth machine. This one also has a few kinks, but essentially a large gear would rotate in the center and it would be turning two smaller gears attached to the wings, making them flap. Unfortunately with this design, one wing would go up as the other went down, and it would also not work with a crank (which is one of our requirements).    This is a pretty cool design my partner made. Instead of traditional "flapping" wings, the wings in this design extend. In these diagrams, there is a large gear in the middle working the wings. After my classes today I went to the lab and fiddled around with  extending methods, and I came up with a workable model. Instead of a gear, I used string attached to a pole that moves horizontally, pulling the wings up and down, making them extend. I don't think it works as well as my first model, but it looks pretty darn awesome.