take the Robot Lee as basic, and it could turn the head too..

Birger T yes i was thinking that buy maybe to tall for the center of gravity?

Of course when the 3D prints of the legs are as thin as paper ;-) Put more weight in the feet..?! Trim the balance with the arm's position and the weight of the hands..?!

I was thinking the same about lee. You just have to be careful of your weight. I shelved many robots because those mini servos where not powerful enough. Judging from the matrix in those eyes, he is quite tall.

we can lower and adapt then according to physics

Ohh Ohh, "gravity" and "balance" gives "calibration & trim" a very new sense for me.
Does the calibration sketch need some new features like to determine and constrain the feets' angles to move to, so the robot won't fall aside? And also to save these params into EEPROM so you won't have to mess with them when using the library functions?

More power with SG90 Servos - i found this
https://www.youtube.com/watch?v=KQkgXA1Z4R0

That first demo is crazy.

Hi Camilo Parra Palacio, OLED displays for the eyes could reduce weight in the head, and give more variety for eye animations - I think
Two 64x64 Oleds for the Eyes and an 128x64 for the teeth?!

Birger T yeah good idea we can use OLED then, i am just having problems with memory... once i put the Otto libraries combines with Adafruit GFX we can only do basic movements

Birger T with the OLED same situation need to simplify those libraries tailored to Otto