How do we, as a community, want to handle drafting (or technical drawing) questions that come up? What are in scope? What are out of scope?
Technical drawing should be mostly out of scope unless it deals with making a technical drawing into a illustration, some basic principles, layout of graphs, producing technical drawings to print or orthographic drawing which may be a graphics designer skill also.
Please note one of my jobs is teaching drafting to very high end automatic CAE/simulation setups at the Aalto University School of Engineering. So im more than capable of answering these questions. I however think they clearly belong to Mechanical engineering SE that's under works. Tough mainly because engineering is a alien concept to most designer and may cause lot of confusion and contradictions.
General rule of thumb would be that once you cross the line into why, and how for more complex concepts your out of scope. 3D cad would be out of scope because you can not avoid the why, how and what you intend. Hence symbolism and what the drafting means is defiitely out of scope.
PS: Technical drawing is (or has been since 1960s) being phased out from drawing so engineers do not draw as much as describe geometry mathematically.
Long ago, I did tech drawing in art school. On paper...
And I agree with Joojaa - technical drawings have certain standards, own language, terms and obey rules that are better found elsewhere. But if you mean "technical" drawings such as assembly instructions, IKEA-style, than I figure that is within scope.
But then that is illustrations, not really technical drawing. Technical drawings are - like botanic "illustration" (they are not really illustrations) - lightyears from graphic design. What I would like to see more of, however, is questions about illustrations as defined in the illustration.