The growing machine (or growth ray) was an invention by Wayne Szalinski. It was intended to make objects grow in size; however, it did not work the way it was supposed to. Its only appearance was in the film Honey, I Blew Up the Kid.
Role in the film
Following the success of his shrinking machine, Wayne Szalinski licensed the device to the Sterling Lab company in Las Vegas. Wayne then worked with Dr. Charles Hendrickson to develop a new machine that could make objects expand in size. However, Hendrickson tried to take over the entire project, going as far as to bar Wayne from working on the machine without his permission.
The machine used the same technology as Wayne's original machine but was much larger in size (taking up an entire room). As with the shrinking machine, the growing one at first did not work correctly and caused objects to explode, rather than change in size. Hendrickson refused to listen to Wayne's suggestions on how to make the machine work.
One Saturday afternoon Wayne brought his two sons, Nick and Adam, to the lab to show them the machine. When they arrived, Smitty, the security guard, thought it was suspicious that Wayne was there on a Saturday, a day he typically didn't work, and alerted Hendrickson.
Wayne knew that the reason why the machine wasn't working was because the intensity of the machine's laser was too high. When he tried to use the computer software to lower the laser intensity, he was given the message "Access Denied." Nick then suggested that they diffuse the laser using the bottom of a soda bottle, which Wayne inserted into the machine's filter pack. Wayne decided to use Adam's favorite stuffed toy, Big Bunny, as a test subject.
While the machine was powering up, Adam slipped out of his stroller to retrieve Big Bunny. As the machine was close to reaching full power, the soda bottle Wayne used to diffuse the laser caused an explosion and a power surge. However, Wayne and Nick were too busy trying to turn the machine off to notice Adam get zapped by the machine's ray. It looked like nothing had happened, but Adam was now surrounded by an electromagnetic flux, which would cause him to grow in size whenever he was near an operating electrical device.
Upon leaving the lab, Smitty informed Wayne that his security clearance denied him access to the lab equipment without Hendrickson's permission. Once they got home, Wayne put Adam in his high chair to give him his lunch. He turned the microwave on, then left the room. The microwave caused Adam to grow to 7 feet tall. Wayne and Nick rushed him back to the lab so they could use the machine to return him to normal size.
When they got there, however, they were confronted by Hendrickson, who informed them that Wayne's experiments had damaged the lab equipment, and as a result Wayne was no longer allowed to work on the project. Wayne informed Hendrickson that he did not have the authority to make such a decision, but Hendrickson told Wayne that the director of the lab, Clifford Sterling, would not want to listen to Wayne after the damage he had caused. Wayne did not, however, tell Hendrickson that he had gotten the machine to work, as he knew Hendrickson would subject Adam to numerous testing.
Ultimately, Wayne got the shrinking machine out of the lab's warehouse where it was being stored and used it to return Adam to normal size (but not before he grew to over 100 feet tall and terrorized Las Vegas). It is unknown what happened to it following the events of the film.