Here is a robot kit that lets owners print their own toys. The X-KIT comes with an app that lets your kids choose what they want to print. You should be able to use this with a variety of 3D printers. Throughout the process, your kids will learn coding and design concepts.
The X-KIT comes with more than 60 robot templates for you to choose from. There are also 40 programs for users to try from the app. The templates are customizable, so your kids can make their own models. Users also get a Hub (brain) and can customize the robot with their own LEGO pieces.