Hi Doddy.
I build miniatures and film them, next to pets, as a hobby. The size of the pets forced me to go with 1:5 scale. That is why the smallest doorway has a width of 16-17cm and I need a robot body that can fit through that easily, and I would go with 12-14cm for that. The height of a door is 40cm, but in order to make the robot cute-ish, I would have him a bit more than half a door height. Click image for larger version. 

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The structure/platform that will house all miniatures will take me until march to complete. It is designed with a thin floor and ceiling, and tested, that I can move a max 2kg object, with the help of neodynium magnets. As I film them, I need for the robot only the illusion of movement, and not necessary the actual robotics. This would be nice just to entertain the kid part of me, but it is optional, and I will easily dump it if there is not enough space.

The tilt/pan option would be great to save me from reaching in the frame each time I need him to turn his head or look up.

The most important part, which is not defined completely as design, but absolutely sure as a functioning principle, is the function3/stepper/4position thing. Even if the proportions of the robot will change very much, it will still include this in a form or other.

I would go with on board batteries, and would like him to work for apx 30 minutes per charge, if it is possible. If I give up the stearing system, I guess I'll make room for the batteries.

I said I would use steppers as the head enclosure is max 10 by 10 by 5-6 cm in heigh and I need two of them fitted in there, but 360 servos might work as well, I don't know yet. Surest way to go is to buy a few of each components I might need, as I live in a village and delivery costs quite a bit. So I would like to make one inclusive order, even if I will not use in the end some of the components. I'm talking the time so I can figure out all the possible components, the whole list and the smallest models of all things, drivers, motors etc.

The structure of the robot is fairly simple, out of hard wood, finger jointed I think. I have only a cnc, and as soon as I will get my hand on those parts and be able to measure them, I'll design the whole thing in artcam and router it. (might need a few prototypes until I get it just right).

I am not sure yet, what type of remote should I use, a play station controller or a arduino made one. From here I can start the list.