Thirteen-year-old Zac Waters of Lehi, Utah, spent 300 hours of his summer building a custom 3D-printed mobility chair for a 21-month-old girl.subscribe to the Laughing Squid NewsletterThe post 13-Year-Old Spends 300 Hours Building a Custom 3D-Printed Mobility Chair for a Toddler was originally published on Laughing Squid.