In a world populated by sentient robots, Rodney Copperbottom is an aspiring young inventor from Rivet Town who idolizes Bigweld, an entrepreneur and philanthropist whose company provides robots with products ranging from everyday appliances to spare parts. Following Bigweld's example to "see a need, fill a need", Rodney creates Wonderbot to assist his dishwasher father Herb. When Herb's supervisor confronts them, Wonderbot panics and wreaks havoc in the kitchen, leaving Herb in debt. To help Herb pay for the damages, Rodney decides to move to Robot City, hoping to present Wonderbot to Bigweld Industries in order to get a job there; despite objections from his mother Lydia, Herb encourages Rodney to pursue his dream, as he gave up his musical ambitions for his safer dishwashing job. Upon arrival at Robot City, Rodney is ejected from Bigweld Industries by his second-in-command Phineas T. Ratchet, who in Bigweld's absence has stopped producing spare parts in favor of expensive "Upgrades", thereby "outmoding" robots who are unable or refuse to pay for them. Ratchet's mother, Madame Gasket, runs the Chop Shop, a facility that collects scrap and spare parts with Sweeper trucks, and melts them to create Upgrades.