@Greg@social.coop I've been using an UltiMaker 2+ for several years. It's very easy to use, I got it pre-assembled. UltiMaker also has excellent software "Cura" for slicing 3D models that's open source (LGPL) and supports a huge variety of printers (not just their own). If you or your children are also into math or programming as a means of creating 3D models (CAD), check out @OpenSCAD@fosstodon.org For a more WYSIWYG style of CAD, I find Shapr3D on the iPad to be elegant, intuitive, and tactile (but proprietary and freemium).