One of the main advantages of current 3D modelers is that they make it possible to construct parametric models, that is to say based on mathematical parameters and expressions allowing the model to easily evolve according to changes and adaptations of the product. throughout his life.
Prepare the design
Warning: I do not pretend here to address professionals, but simply passionate amateurs who want to use FreeCAD with more confidence.
The possibility of product development must therefore be anticipated from its conception.
Preparing your design means at least:
have a global idea, however imprecise, of the project to be carried out before starting;
identify and list the basic dimensions (parameters) whose values may change;
sketch the silhouettes of the objects to be built;
predict the interdependence between these objects ...
Robustness of the model
A recurring problem of "toponaming" (naming internal to FreeCAD of geometric entities such as faces, edges and vertices) sometimes causes unwanted results when modifying certain geometries. The latest work from Realthunder (creator of the Assembly 3 WB) has greatly improved FreeCAD's behavior in this area.
However it is prudent to use for the construction of robust models the reference planes rather than the faces of the objects to draw in order to further reinforce the robustness of our work.
Other tools such as the creation of reference geometries (planes, lines or points) positionable as desired in space reinforce this robustness.
Two proposals to go further ...
a project explained with interdependence of the parts (assembly without assembly constraints);
a list of "How to ..." to find various cases separately.