Hi c/FreeCAD, totally newbie here! I’m having a ton of fun learning FreeCAD, but I have a small question. I know the toponaming problem is going away soon, and maybe that makes this kind of irrelevant, but I’d still like to know.

Sometimes when I’m watching or reading guides on avoiding the toponaming problem, the person will say something along the lines of: “actually this technique is also more professional/proper/correct anyway, real engineers do it this way.” Basically that the methods that avoid the problem are also just best practices in general. But they always say that as kind of an aside, and I wish they’d say more! What makes those methods better? Does anyone have any suggestions for articles or videos about this?

For one example, there was one guide that suggested you should use a datum plane instead of referencing one of the object’s surfaces. I understand the toponaming problem well enough to get why referencing a surface can cause it. However, the person in the guide used the same surface that would have been referenced, as the attachment point for the datum plane. Why does that not produce the same issue?

  • kersplooshA
    5•3 days ago

    I’ll use datum planes rather than drawing directly on object faces

    I haven’t had a chance to try FreeCAD, but this is generally good advice in other parametric CAD tools, too. Create “skeleton” features early on (planes, datums, simple sketches) and define later features by referencing the skeleton as much as possible. It avoids creating a long chain of feature dependencies where Feature A changes and breaks Feature B, which breaks Feature C, etc.