Autodesk TinkerCAD
Autodesk TinkerCAD is a free CAD software by Autodesk. It allows you to “make anything” in 3 dimensions. TinkerCAD is usually used by amateurs and beginners who are trying to understand CAD and do not have any prior knowledge of CAD modeling. They are mostly used by kids, teachers, hobyists and amateur designers. You can make 3d designs of objects, create electronic circuits and can create your own objects using codeblocks. The object you create can be exported as STL files for printing using 3D printers.