Anamatronic Evil Eyes Proof of Concept

For Halloween, I’d like to build some evil glowing eyes that can follow a person and blink. Yesterday I got various stats about the human eye together to build something that would look human-like and obviously show motion as they followed you.

Today I put together a very primitive proof of concept to see if what I’m thinking would look realistic:

anamatronic eyes-1

anamatronic eyes-2

The idea wasn’t perfect, but it wasn’t bad. They obviously showed a scanning motion; however, I don’t think the tubes looked human enough the way light reflected off the sides.

I’m going to try this again with ping pong balls to see what that looks like.

This entry was posted in Animatronic Evil Eyes, c-electronics. Bookmark the permalink.

3 Responses to Anamatronic Evil Eyes Proof of Concept

  1. Sean Straw says:

    From the length of the LED leads out the back of your tubes, it appears the LEDs are mounted pretty far back in the tubes, which would lead to an exaggeration of their directionality. To address the reflection on the inside, you could try applying some flat black paint (if it’ll adhere to the tube material), or get some adhesive on there and brush on some black charcoal dust (take a briquette and run it on fine sandpaper).

    Coincidentally, I just wrapped up a project for timing belt sander races at my office using LDRs (Light Dependent Resistors) that are mounted inside short lengths of black straws (chiefly to make their light sensing very directional and make it easier to mount them, and hot glued from the bottom of the straw to hold the LDR in place.

    For effect, a pair of ping pong balls (though large), with an iris painted on the front (possibly draw radials with a fine tip Sharpie and then paint in the iris with glass paint, which is more translucent and won’t be a black blotch) and a diffuse LED at _less_than_full_brightness_ (PWM if you want to adjust it, or a higher value current limiting resistor) would lend to the effect. You can take a regular 5mm crystal lens and sand the head of it to diffuse it to some extent. An RGB led (or a second red led, perhaps even 3mm) would enable you to switch from normal (as it were) to evil eyes, etc.

    Between lower brightness and diffusing the LED(s), that should minimize the hot spot projection of light on the inside of the orb so it’s more of an even light, though I won’t expect it to be perfect.

    You might be able to cut or drill a hole in the ping pong ball, but heating a nail with a lighter (or using a soldering iron tip, though I don’t like to abuse my tools), and pressing it into the back of the ball should do the job nicely and prevent fractures – ping pong balls can be kind of weird. I’d put the hole where the logo and ball rating is so that the front of your orb is a blank canvas.

    To get the ping pong balls to pivot nearer to the rear or the orb, you could melt a tiny hole at the top and bottom and run a pin/wire through. As a comparison, hold your hands apart as if you were an inch or two from clapping them and pivot them side to side keeping them parallel – as you move to either side, the “outboard” side will be more forward than the other. Now, hold your hands as if you were making “glasses” with them, but hold your thumbs and index fingers as if your were holding a cirtca 1.5″ square box at the corners. if you move your fingers as if you are dialing two adjacent volume control knobs (on something with an actual knob, instead of a swipe motion), you’ll see that one “eye” or the other does not appear to project forward just because they rotate. This is more like an actual eye – moving your eyes to one side or the other does not cause one to protrude and the other to retract.

  2. Sean Straw says:

    No active blog. Don’t use wordpress myself, and have multiple websites which haven’t been updated in forever and a day.

    I’m an embedded software engineer by day, and electronic tinkerer, beekeeper, woodworker, gardener, auto enthusiast, and photographer as time permits. And father, and…

    So many interests, so little time.

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