Did Will Robinson build the robot in the Lost in Space movie? Or was it someone else?
The robot was built as part of the ship in the movie. Smith sneaks on board to program the robot to destroy the ship and is double-crossed after doing so (which traps him there). This is how the robot initially appears
Smith is forced to awaken the Robinsons to save himself and stop the rampaging robot. They do so, but wreck the robot in the process. Will then rebuilds the robot into one that looks more like the one in the original series