I'm in the process of creating more(!) threads (I like to write to organise my thoughts, I figure I may as well kill two birds with one stone and post those thoughts for the benefit of anyone who might find them useful), but finding that I don't just wonder and posit conceptual ideas, but am actually interested in the nuts and bolts of machine design. This doesn't really fit into "Concepts and Ideas", but it's broader than any one of the build thread subforums- acceleration, precession, bending moments, materials, etc. can be applied to any of the build types, and aren't necessarily specific to OpenBuilds- for example, the Ultimo build and its custom superstructure, with OpenBuilds hardware applied at specific points. Nor does it need to overtake discussion of individual projects. There's a spot for Electronics- it seems like there should be a matching subforum for Mechanics- where instead of Motors, Boards, Interfaces and General it's like, Propulsion, Structure, Materials and General. Or something. I guess structure and materials are conceptually inseparable, but at least there would be separate spots to discuss "optimum V-Slot dimensions" and "appropriate rock gradings for Epoxy Granite" without them burying each other too much. Not sure if anyone else cares too much? I'd certainly like to hear more about @Brian Slee's experimentation with concrete and reinforcement types, as well as look it myself, anyway!