Jumping around a little bison this project. I decided I needed to sort out how the eyes and eyelids of the head on the the Bipolar Brain were going to work before getting to far on the mechanical design. Pictured below are the two eyeballs and eyelids I have made.
Making the eyelids is a potential finger ripper. Trying to cut the lemon wedge shaped piece to start the process is tricky. Cutting a 1-1/2" diameter ball on a bandsaw or scroll saw is a way to nip a finger. If you don't have a firm grip on the ball, it can roll, pulling itself into the blade, maybe fingers and all. Even clamping it is no guarantee. I use a different yet slower approach. I sand the ball on my bench sander. Getting a flat stated still requires care, but once started it goes easily enough. These wedges end up at 135 degrees of the original ball.
The trick then is to hollow out the inside to allow the eyeball to fit freely. I do this with a burr on my Dremel tool, using a calliper gauge to work to a uniform thickness for the eyelid.
I figure a sandpaper burn rather than a cut finger is a better deal, but having made a few of these in the past I came through these unscathed! These bigger eyes are easier than the small ones. You can see the pivot hole in one of the eyelids.
Automata is a creative blend of my life interests , engineering, art and woodworking.