Even in a world populated entirely by mechanical beings Rodney Copperbottom is considered a genius inventor. Rodney dreams of two things, making the world a better place and meeting his idol, the master inventor Bigweld. On his journey he encounters Cappy, a beautiful executive bot with whom Rodney is instantly smitten, the nefarious corporate tyrant Ratchet who locks horns with Rodney, and a group of misfit bots known as the Rusties, led by Fender and Piper Pinwheeler.