FreeCAD

Download and install FreeCAD: FreeCAD: Your own 3D parametric modeler

FreeCAD, jargon:

• "Placement": Placement - FreeCAD Documentation
• Can I drive Placement using Python?
• "Apply incremental": How to simply use: Placement "Apply incremental" [Python] - FreeCAD Forum
• "Expressions": Expressions - FreeCAD Documentation
• "Simulation": Freecad: Spring animation / simulation in Python. Beginners guide to macro programming / scripting