Create 3 App::Link, and position them side by side, this will be the first animation step.
I’m not sure if these type of questions are tolerated here. The STEP computer-aided design file type was released in 1994 after a decade of development to make it easier to share geometric models. Freecad explode step file FreeCAD is based on Open CASCADE technology and its own main file format is FreeCAD Standard file format (.