This is an expandable robot chassis. You can find the basic bluetooth build instructions here:
Building it is quick but it takes approximately 35 hours to print in its entirety. All the .stl files are here, separated for 3d printing, but the entire design is here under robotLatest.123dx for 123d Design. If your just doing the basic bluetooth build that I have made instructions for, you don't need to print the neckOneServo.stl piece or the neckBothServos.stl piece. Those are just in case you want to add motion to the head. neckOneServo.stl is up and down, and neckBothServos.stl is up down, and left to right (not demoed in the video because it doesn't work that well).
If you have any questions I would be glad to help, I am sure there are some things I missed.
Everything prints pretty nicely, if I remember correctly you only need supports when printing the middle pieces. I would definitely use a raft on both face pieces. I did not use a raft when doing mine because I was too impatient and I got a lot of warping and poor adhesion.
This was designed in 123d design because I thought it would be easier for younger people to change designs of the face or whatever else they wanted to edit.