Let's Make Robots!

Prototype animatronic head

Well my boss is involved in organizing a robot head building contest in China and asked me to make an example to inspire the contestants. I know many will just be made from cardboard and wood but I decided that if I was going to spend time on this project then I wanted to make the most of it and develop a new product.

Some of the animatronic heads I've seen on Youtube are very advanced with custom machined metal parts and 20 -30 servos. I decided to try and make this design flexible. It can work with as little as 4 servos or as many as 11 and all servos have magnetic clutches to protect the gears. The head is intended to have a rubber halloween mask fitted to it.

Two servos are used for the mouth with flexible spring wire lips. This allows the mouth to open, close, smile, frown or grimace. A third servo can be mounted behind the lips to move bottom teeth up/down or a tongue in and out.

The eyes can be controlled with as little as 2 servos (up/down and left/right) but adding another 2 servos will allow the eyes to pan individually for "cross eyes" and blink assuming I can find 40mm table tennis balls to go over the 38mm eyeballs. It seems most table tennis balls in China are 38mm these days.

The eyebrows can be driven by 2 servos for basic movements (up or down can express sad, angry or even curious) or 4 servos for a full range of human expression.

To control these servos, there is room inside the head for a DAGU Mini Driver. Although this board can only drive 8x servos directly from the battery, it's 5V regulator is rated for 1A and can drive a couple of extra servos from the analog inputs (D14-D19) as long as they are lightly loaded.

The Mini Driver has a dual "H" bridge which need not go to waste. 1 motor can be a shaker like they used in some game console hand controllers. This will let the head shiver when it is cold. The other motor output can be used to drive bi-colour LEDs for the eyes. Another option would be a small fan inside the head so it can blow out a candle.

The head will be assembled from 4mm thick, clear acrylic plates held together with small steel 90° brackets and screws. The base can accept a 6mm or ¼ inch bolt or it can be mounted on a heavy duty servo.

Once I get the prototype working I will post it as a robot project.


I am told the laser cut parts will arrive either 9th or 10th of Octoberand my company has bought a small sample of rubber masks to experiment with.

The Clown mask will probably work best with the eybrows but I must admit I think the gorilla would be fun.




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I wonder how this will turn out as a final product...

If notihing else, you can wire up two prototypes and dress your three-headed-mutant self up and watch the scared little people run!

Wow! I really like the format of how its constructed, in addition to the placement of servos! Well done, OddBot! :)

I've tried to keep it easy to assemble so the main head has only 4 parts. All up there are about 20 laser cut parts, most for the eyes.

Way too much fun for just one person.......

This looks great OddBot
Just one thing… Do you need two servos for the movement of the eyes up and down? I have never seen anyone able to move them individually up/down..

Ideally a wire linkage should join both eyes to one servo so that they both go up and down together and the other servo will blink eyelids assuming I can find the older 40mm table tennis balls.

The only time I have seen eyes move up and down idependantly was in cartoons (when they get hit on the head and the eyes roll independantly of each other) so this head does allow for the possibility of silly cartoon faces.

If this does get sold as a kit then it probably get sold with 8 servos and the rest are optional. When I designed the head I tried to think of every possible configuration the end user might want to try.

hahaha! that's just creepingly awesome!

Just wait until i fit a halloween mask on the prototype and program it, then you will see creepy!

Hmm.. reminds me of a night at the KTV. These two/three? fine gentlemen freaked out more than a few girls at the club.

Zaphod Beeblebrox eat your heart out! You only had two heads!

I can't see the hair to be sure. In any case, I had four leftover ping pong balls from Serv-O and I thought "Hey, if I sent them to OddBot they wouldn't go to waste (I don't play ping pong) and we could see how long it takes to ship from the US to China instead of the other way round for once." So I grabbed one and ran it through the calipers and wouldn't you know it-they're only 37.5 mm in diameter! Even smaller. I had a hell of a time finding even those! I'll keep my eyes open for you though.

Max, how rude LOL.

Either the guy on OddBot's left or our left (his right) looks anything like me. I never had a beard and last time I watched my mirror image it was much younger than OddBot's friends :-)

I guess the shipping from USA to China will take even more time than the other way around.