This is my animatronic toucan head built out of knex. It has two servos which control each section of the beak independently and a DC worm gear motor which drives the neck rotation motion.

This instructable will give you a general idea of how I put it together and the control system.

Step 1: Beak Sections

I started this build with the beak without any real idea of where it was going to go or how big it was going to be. I didn't even have the intentions of making it move so it definitely evolved as it was developed.

I haven't included a parts list for this build either as it just uses a whole heap of K'nex and two servo motors.

Step 2: Head Mechanism

I tried to balance the weight of the beak parts around the pivot point to reduce the load on the servos. It actually takes very little force to move each beak section so I first set this up with 9g micro servos (you know them crappy little plastic things which have a duty cycle of about 3%) which had enough torque to move the sections but they were a pain in the arse to mount in the knex so I upgraded to some larger servos which fit the knex structure a lot better (more on that later).

Step 3: Skinned Mesh Render

Making a curved surface out of knex is always a pain in the arse, at work we just use silicon and fibreglass but where's the fun in that eh?

And eyes. Such a pain in the arse! Must have made these eyes about 5 times before I gave up/was happy with them.

Step 4: Adding the Rotating Neck Mechanism

The rotating neck mechanism is very similar to the mechanism used in the tower crane model, see here:

http://media.knex.com/instructions/instruction-boo...

The mechanism really didn't take long to make but it was quite difficult getting the correct gearing ratio for the motor to drive the head at a reasonable speed,

Step 5: Servo Install

Sorry about the picture quality here, my camera could't seem to focus on anything and there's quite a lot going on in the pictures so hopefully they make a bit of sense but you know what a servo looks like so I'm sure you can imagine how it fitted in the model.