Project If This Then That Documentation (Animatronic Head)

For this arduino project i made a animatronic face that can move it's eyes when you put your hand in front of a sensor. It can also move its jaw and eyelids on it's own.

This is a documentation for a school project. It's also my first time working with arduino and making a animatronic head. If there are any tips you would like to give please feel free to do so!

Worbla (material for the face and other parts)

Copper wire

Tiny screws and or bolts

Arduino

Breadbord

Sonar sensor

Wires

3 micro servo's

glue

optional:

Doll head to serve as a mold

female wires so you can make the sonar sensor wireless

First i started sketching out my concept and how i wanted to make it work. I watched a few youtube video's that served as inspiration and research.

I started with the jaw. At first i wanted to attach the servo to the jaw itself, but this would put to much strain on the servo. I needed a mechanism that would make it easier for it to move the jaw up and down. After some more research i found that you could make sort of a U shape from the jaw to the top of the head where the servo will be. I thought this mothod would work very well for my project.

After that the eyes and eyelids. These were really challenging. There a a few ways to make it work and you can see from the sketches i had some different ideas. eventually i made the decision to put a wire between the eyes to attach those to a servo to make them move in unison. As for the eyelids, i would also connect then with a wire. pretty much the same as the eyes. But instead of pushing them left and right i would push them up and down with a servo. This way the presure of pushing them down would lover the eyelid and when the servo would pull up, the eyelids would be pulled up aswell.

When it comes to prototyping the jaw is unfortunatly due to time the only thing i really made a few protypes on. First i made one out of paper to quickly see how the jaw would work and move. Next i made a more advanced one out of cardboard and taped a servo at the top of its head so i could watch it in action.

Now it was time to really start building the animatronic, starting with the head. I bought two things to make this. a mannequin head as a base. and a material called Worbla to make a sort cast from the head. For those who don't now what Worbla is, it's a material that feels alot like a bendable plastic. When you heat it up is starts to become very soft and flexible so you can mold stuff out of it. Many cosplayers use this material aswell for their cosplays.

I started out heating up a piece of Worbla that would fit around the mannequins head (not including the jaw and back of the head). After it was heated i folded it over the head and did my best to smooth out as many overlaps as i could in the material. I made sure to get the matrial deep into every crevice on the head to make sure i got all the details. When the cast hardened as it cooled down i cut out the eyes with a boxcutter and trimmed away any excess Worbla.

i repeaded this the process for the lower jaw. The reason i keep them sepperate and not just cut the jaw off the head after i casted it is so that i can make a little extension at the base of the jaw that moves upwards. this ways i can connect the jaw to the head more easily.

This part was the most difficult. To start i made what i like to call little catwalks inside the head where my eyes, eyelids and servo's go. In total i made three. One for the eyes and eyelids, one for the servo of the eyes and one for the servo of the eyelids and the servo of the jaw.

The eyes were very diffcult to make. i also made the eyes out of Worbla en needed to make a hole in them so i could put them in a wire or screw so they could move. Making a hole inside a ball of Worbla would prove pretty challenging. Eventually i used a drill to make a hole in each. Ati first i was going to use copper wire to keep them in place but eventually decided a screw would work better. I also made two holes in the catwalk so i could attach the eyes to them. I connected the eyes with a copper wire and attached that to the servo.

For the eyelids i made little support walls to keep them in place. I put two in the middle and one on either side on the inside of the head. The eyeslids were also made from Worbla. I made them to look like 1/4, 1/5 of a sphere. I put holes on either side of the eyelid and attached them to the supports with copper wire. Just like i did with the eyes i connected them with another copper wire and connected it directly to a servo laying on it's side.

I tried attaching the servo's themselves to the catwalks with glue. This unfortunatly did not work. Not having any more screws i put tiny metal cages over the servos out of copper wire and bended the wire around the catwalk. This way, the servo's stayed in place

For the eyes i have put up the sonar senor and told it that if it's triggered the servo needed to move a certain amount of degree's. Ofcourse i tested out a few diffirent numbers to see what gives the best result. As for the jaw and eyelids, they have code that loops over and over so that they keep moving. My eyes are servo 1, my jaw servo 2 and my eyelids servo 3.

The finished product is a head that can move it's jaw, look with it's eyes and blink. Unfortunatly in my case one of the eyelids got stuck against the front of the head and couldnt move down. With some time and care i would be able to fix this by cutting of a piece of the eyelid or shaving of a bit of the eye that it's bumping up against. The mechanics themselfs however do all work.