openscad Beta 2 Release of Models @ MWT Models @ MakeWithTech is on only search application and customizer for OpenSCAD models.
3d Printing Create Your Own 3d Models The DrVax YouTube channel features a playlist highlighting popular 3d design tools capable of creating models for 3d printing.
Software FreeCAD Tutorial Series FreeCAD is an open-source parametric CAD application installable on Windows, macOS, or Linux. Watch the following video to begin your journey into CAD. Learning CAD, while not trivial, is worth the effort.