Robots geometry based mostly on extruding method, all main parts are separated.
The hierarchy observed in parts of the body, full skeleton is built-in, (big one robot - including fingers). All main parts of the body ready for animation (sit-up, running, jumping and so on).
Attached files contents materials and Maya mental ray render as in the picture.
File .obj attached also as zip archive.
Each robot are available as separated project (ID 553551 and 560080).